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  Subjects -> ENGINEERING (Total: 2449 journals)
    - CHEMICAL ENGINEERING (208 journals)
    - CIVIL ENGINEERING (208 journals)
    - ELECTRICAL ENGINEERING (116 journals)
    - ENGINEERING (1288 journals)
    - ENGINEERING MECHANICS AND MATERIALS (394 journals)
    - HYDRAULIC ENGINEERING (56 journals)
    - INDUSTRIAL ENGINEERING (81 journals)
    - MECHANICAL ENGINEERING (98 journals)

CIVIL ENGINEERING (208 journals)                  1 2 | Last

Showing 1 - 200 of 208 Journals sorted alphabetically
ACI Structural Journal     Full-text available via subscription   (Followers: 20)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 3)
Acta Structilia : Journal for the Physical and Development Sciences     Open Access   (Followers: 3)
Advances in Civil Engineering     Open Access   (Followers: 41)
Advances in Structural Engineering     Full-text available via subscription   (Followers: 33)
Agregat     Open Access   (Followers: 1)
Ambiente Construído     Open Access   (Followers: 1)
American Journal of Civil Engineering and Architecture     Open Access   (Followers: 35)
Architectural Engineering     Open Access   (Followers: 5)
Architecture and Engineering     Open Access  
Architecture, Civil Engineering, Environment     Open Access  
Archives of Civil and Mechanical Engineering     Full-text available via subscription   (Followers: 3)
Archives of Civil Engineering     Open Access   (Followers: 12)
Archives of Hydro-Engineering and Environmental Mechanics     Open Access   (Followers: 2)
ATBU Journal of Environmental Technology     Open Access   (Followers: 4)
Australian Journal of Structural Engineering     Full-text available via subscription   (Followers: 7)
Baltic Journal of Road and Bridge Engineering     Open Access   (Followers: 1)
BER : Building and Construction : Full Survey     Full-text available via subscription   (Followers: 10)
BER : Building Contractors' Survey     Full-text available via subscription   (Followers: 2)
BER : Building Sub-Contractors' Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Building and Construction : An Executive Summary     Full-text available via subscription   (Followers: 3)
Berkeley Planning Journal     Open Access   (Followers: 5)
Bioinspired Materials     Open Access   (Followers: 5)
Bridge Structures : Assessment, Design and Construction     Hybrid Journal   (Followers: 14)
Building & Management     Open Access   (Followers: 2)
Building and Environment     Hybrid Journal   (Followers: 15)
Building Women     Full-text available via subscription  
Built Environment Project and Asset Management     Hybrid Journal   (Followers: 15)
Bulletin of Pridniprovsk State Academy of Civil Engineering and Architecture     Open Access   (Followers: 6)
Canadian Journal of Civil Engineering     Hybrid Journal   (Followers: 13)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 6)
Case Studies in Nondestructive Testing and Evaluation     Open Access   (Followers: 11)
Case Studies in Structural Engineering     Open Access   (Followers: 9)
Cement and Concrete Composites     Hybrid Journal   (Followers: 20)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 3)
Challenge Journal of Structural Mechanics     Open Access   (Followers: 5)
Change Over Time     Full-text available via subscription   (Followers: 2)
Civil and Environmental Engineering     Open Access   (Followers: 8)
Civil and Environmental Engineering Reports     Open Access   (Followers: 8)
Civil and Environmental Research     Open Access   (Followers: 17)
Civil Engineering = Siviele Ingenieurswese     Full-text available via subscription   (Followers: 4)
Civil Engineering and Architecture     Open Access   (Followers: 23)
Civil Engineering and Environmental Systems     Hybrid Journal   (Followers: 3)
Civil Engineering and Technology     Open Access   (Followers: 12)
Civil Engineering Dimension     Open Access   (Followers: 11)
Civil Engineering Infrastructures Journal     Open Access   (Followers: 1)
Cohesion and Structure     Full-text available via subscription   (Followers: 2)
Composite Structures     Hybrid Journal   (Followers: 290)
Computer-aided Civil and Infrastructure Engineering     Hybrid Journal   (Followers: 11)
Computers & Structures     Hybrid Journal   (Followers: 37)
Concrete Research Letters     Open Access   (Followers: 7)
Construction Economics and Building     Open Access   (Followers: 4)
Construction Engineering     Open Access   (Followers: 11)
Construction Management and Economics     Hybrid Journal   (Followers: 21)
Constructive Approximation     Hybrid Journal  
Curved and Layered Structures     Open Access   (Followers: 3)
DFI Journal : The Journal of the Deep Foundations Institute     Hybrid Journal   (Followers: 1)
Earthquake Engineering and Structural Dynamics     Hybrid Journal   (Followers: 17)
Enfoque UTE     Open Access   (Followers: 4)
Engineering Project Organization Journal     Hybrid Journal   (Followers: 7)
Engineering Structures     Hybrid Journal   (Followers: 13)
Engineering Structures and Technologies     Open Access   (Followers: 2)
Engineering, Construction and Architectural Management     Hybrid Journal   (Followers: 10)
Environmental Geotechnics     Hybrid Journal   (Followers: 5)
European Journal of Environmental and Civil Engineering     Hybrid Journal   (Followers: 10)
Fatigue & Fracture of Engineering Materials and Structures     Hybrid Journal   (Followers: 19)
Frontiers in Built Environment     Open Access   (Followers: 1)
Frontiers of Structural and Civil Engineering     Hybrid Journal   (Followers: 6)
Geomaterials     Open Access   (Followers: 3)
Geosystem Engineering     Hybrid Journal   (Followers: 2)
Geotechnik     Hybrid Journal   (Followers: 4)
Géotechnique Letters     Hybrid Journal   (Followers: 8)
GISAP : Technical Sciences, Construction and Architecture     Open Access  
HBRC Journal     Open Access   (Followers: 2)
Hormigón y Acero     Full-text available via subscription  
HVAC&R Research     Hybrid Journal  
Indonesian Journal of Urban and Environmental Technology     Open Access  
Indoor and Built Environment     Hybrid Journal   (Followers: 3)
Infrastructure Asset Management     Hybrid Journal   (Followers: 3)
Infrastructures     Open Access  
Ingenio Magno     Open Access   (Followers: 1)
Insight - Non-Destructive Testing and Condition Monitoring     Full-text available via subscription   (Followers: 30)
International Journal for Service Learning in Engineering     Open Access  
International Journal of 3-D Information Modeling     Full-text available via subscription   (Followers: 3)
International Journal of Advanced Structural Engineering     Open Access   (Followers: 17)
International Journal of Civil, Mechanical and Energy Science     Open Access   (Followers: 2)
International Journal of Concrete Structures and Materials     Open Access   (Followers: 15)
International Journal of Condition Monitoring     Full-text available via subscription   (Followers: 2)
International Journal of Construction Engineering and Management     Open Access   (Followers: 10)
International Journal of Engineering and Geosciences     Open Access  
International Journal of Geo-Engineering     Open Access   (Followers: 3)
International Journal of Geosynthetics and Ground Engineering     Full-text available via subscription   (Followers: 4)
International Journal of Masonry Research and Innovation     Hybrid Journal   (Followers: 1)
International Journal of Pavement Research and Technology     Open Access   (Followers: 6)
International Journal of Protective Structures     Hybrid Journal   (Followers: 6)
International Journal of Steel Structures     Hybrid Journal   (Followers: 2)
International Journal of Structural Engineering     Hybrid Journal   (Followers: 9)
International Journal of Structural Integrity     Hybrid Journal   (Followers: 2)
International Journal of Structural Stability and Dynamics     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Built Environment     Open Access   (Followers: 5)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 8)
International Journal on Pavement Engineering & Asphalt Technology     Open Access   (Followers: 7)
International Journal Sustainable Construction & Design     Open Access   (Followers: 2)
Journal of Applied Research in Water and Wastewater     Open Access   (Followers: 1)
Journal of Bridge Engineering     Full-text available via subscription   (Followers: 13)
Journal of Building Engineering     Hybrid Journal   (Followers: 2)
Journal of Building Materials and Structures     Open Access   (Followers: 2)
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 6)
Journal of Civil Engineering     Open Access  
Journal of Civil Engineering and Construction Technology     Open Access   (Followers: 15)
Journal of Civil Engineering and Management     Open Access   (Followers: 7)
Journal of Civil Engineering and Science     Open Access   (Followers: 9)
Journal of Civil Engineering Research     Open Access   (Followers: 7)
Journal of Civil Engineering, Science and Technology     Open Access   (Followers: 1)
Journal of Civil Society     Hybrid Journal   (Followers: 5)
Journal of Civil Structural Health Monitoring     Hybrid Journal   (Followers: 4)
Journal of Composites     Open Access   (Followers: 78)
Journal of Composites for Construction     Full-text available via subscription   (Followers: 13)
Journal of Computing in Civil Engineering     Full-text available via subscription   (Followers: 23)
Journal of Construction Engineering     Open Access   (Followers: 9)
Journal of Construction Engineering and Management     Full-text available via subscription   (Followers: 17)
Journal of Constructional Steel Research     Hybrid Journal   (Followers: 6)
Journal of Earth Sciences and Geotechnical Engineering     Open Access   (Followers: 4)
Journal of Fluids and Structures     Hybrid Journal   (Followers: 6)
Journal of Frontiers in Construction Engineering     Open Access   (Followers: 2)
Journal of Green Building     Full-text available via subscription   (Followers: 10)
Journal of Highway and Transportation Research and Development (English Edition)     Full-text available via subscription   (Followers: 14)
Journal of Infrastructure Systems     Full-text available via subscription   (Followers: 19)
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction     Full-text available via subscription   (Followers: 5)
Journal of Marine Science and Engineering     Open Access   (Followers: 1)
Journal of Materials and Engineering Structures     Open Access   (Followers: 5)
Journal of Materials in Civil Engineering     Full-text available via subscription   (Followers: 8)
Journal of Nondestructive Evaluation     Hybrid Journal   (Followers: 9)
Journal of Performance of Constructed Facilities     Full-text available via subscription   (Followers: 3)
Journal of Pipeline Systems Engineering and Practice     Full-text available via subscription   (Followers: 6)
Journal of Rehabilitation in Civil Engineering     Open Access   (Followers: 3)
Journal of Solid Waste Technology and Management     Full-text available via subscription   (Followers: 1)
Journal of Structural Engineering     Full-text available via subscription   (Followers: 35)
Journal of Structural Fire Engineering     Full-text available via subscription   (Followers: 6)
Journal of Structural Mechanics     Open Access   (Followers: 1)
Journal of Structures     Open Access   (Followers: 4)
Journal of Sustainable Architecture and Civil Engineering     Open Access   (Followers: 3)
Journal of Sustainable Design and Applied Research in Innovative Engineering of the Built Environment     Open Access   (Followers: 1)
Journal of the Civil Engineering Forum     Open Access  
Journal of the South African Institution of Civil Engineering     Open Access   (Followers: 2)
Journal of Water and Environmental Nanotechnology     Open Access  
Journal of Water and Wastewater / Ab va Fazilab     Open Access  
Jurnal Spektran     Open Access   (Followers: 1)
Jurnal Teknik Sipil     Open Access  
Jurnal Teknik Sipil dan Perencanaan     Open Access   (Followers: 1)
Konstruksia     Open Access  
KSCE Journal of Civil Engineering     Hybrid Journal   (Followers: 2)
Latin American Journal of Solids and Structures     Open Access   (Followers: 4)
Materiales de Construcción     Open Access   (Followers: 1)
Mathematical Modelling in Civil Engineering     Open Access   (Followers: 4)
Media Komunikasi Teknik Sipil     Open Access  
Mokslas – Lietuvos ateitis / Science – Future of Lithuania     Open Access  
Nondestructive Testing And Evaluation     Hybrid Journal   (Followers: 15)
npj Materials Degradation     Open Access  
Obras y Proyectos     Open Access   (Followers: 1)
Open Journal of Civil Engineering     Open Access   (Followers: 9)
Periodica Polytechnica Civil Engineering     Open Access  
Photonics and Nanostructures - Fundamentals and Applications     Hybrid Journal   (Followers: 4)
Practice Periodical on Structural Design and Construction     Full-text available via subscription   (Followers: 3)
Proceedings of the Institution of Civil Engineers - Bridge Engineering     Hybrid Journal   (Followers: 8)
Proceedings of the Institution of Civil Engineers - Civil Engineering     Hybrid Journal   (Followers: 14)
Proceedings of the Institution of Civil Engineers - Management, Procurement and Law     Hybrid Journal   (Followers: 10)
Proceedings of the Institution of Civil Engineers - Municipal Engineer     Hybrid Journal   (Followers: 2)
Proceedings of the Institution of Civil Engineers - Structures and Buildings     Hybrid Journal   (Followers: 3)
Promet : Traffic &Transportation     Open Access  
Random Structures and Algorithms     Hybrid Journal   (Followers: 5)
Recent Trends In Civil Engineering & Technology     Full-text available via subscription   (Followers: 5)
Research in Nondestructive Evaluation     Hybrid Journal   (Followers: 6)
Resilience     Open Access   (Followers: 1)
Revista IBRACON de Estruturas e Materiais     Open Access   (Followers: 1)
Revista Sul-Americana de Engenharia Estrutural     Open Access  
Road Materials and Pavement Design     Hybrid Journal   (Followers: 11)
Russian Journal of Nondestructive Testing     Hybrid Journal   (Followers: 5)
Science and Engineering of Composite Materials     Hybrid Journal   (Followers: 61)
Selected Scientific Papers - Journal of Civil Engineering     Open Access   (Followers: 3)
Slovak Journal of Civil Engineering     Open Access   (Followers: 2)
Soils and foundations     Full-text available via subscription   (Followers: 5)
Steel Construction - Design and Research     Hybrid Journal   (Followers: 3)
Structural and Multidisciplinary Optimization     Hybrid Journal   (Followers: 11)
Structural Concrete     Hybrid Journal   (Followers: 11)
Structural Control and Health Monitoring     Hybrid Journal   (Followers: 8)
Structural Engineering International     Full-text available via subscription   (Followers: 11)
Structural Mechanics of Engineering Constructions and Buildings     Open Access   (Followers: 1)
Structural Safety     Hybrid Journal   (Followers: 6)
Structural Survey     Hybrid Journal  
Structure     Full-text available via subscription   (Followers: 24)
Structure and Infrastructure Engineering: Maintenance, Management, Life-Cycle Design and Performance     Hybrid Journal   (Followers: 12)
Structures     Hybrid Journal   (Followers: 1)
Study of Civil Engineering and Architecture     Open Access   (Followers: 10)
Superlattices and Microstructures     Hybrid Journal   (Followers: 2)
Surface Innovations     Hybrid Journal  
Technical Report Civil and Architectural Engineering     Open Access   (Followers: 1)
Teknik     Open Access  
Territorium : Revista Portuguesa de riscos, prevenção e segurança     Open Access  
The IES Journal Part A: Civil & Structural Engineering     Hybrid Journal   (Followers: 6)

        1 2 | Last

Journal Cover
International Journal of Structural Stability and Dynamics
Journal Prestige (SJR): 1.005
Citation Impact (citeScore): 2
Number of Followers: 7  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0219-4554 - ISSN (Online) 1793-6764
Published by World Scientific Homepage  [118 journals]
  • Reference-Free Breathing Crack Identification of Beam-Like Structures
           Using an Enhanced Spatial Fourier Power Spectrum with Exponential
           Weighting Functions
    • Authors: J. Prawin, A. Rama Mohan Rao
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Detection of incipient damage of structures at the earliest possible stage is desirable for successful implementation of any health monitoring system. In this paper, we focus on breathing crack problem and present a new reference-free algorithm for fatigue crack detection, localization, and characterization for beam-like structures. We use the spatial curvature of the Fourier power spectrum as a damage sensitive feature for fatigue crack identification. An exponential weighting function that takes into account nonlinear dynamic signatures, such as sub- and superharmonics, is proposed in the Fourier power spectrum in order to enrich the damage-sensitive features of the structure. Both numerical and experimental studies have been carried out to test and verify the proposed algorithm.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-09-14T09:48:48Z
      DOI: 10.1142/S0219455419500172
       
  • Thermo-Mechanical Buckling of CFRP Cylindrical Shells with FGPM Coating
    • Authors: Kai Xu, Zhenhuan Zhou, Qingzhen Lu, Jiabin Sun, Ziguang Jia
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, the buckling behaviors of cylindrical shells made of a new kind of carbon fiber reinforced polymer (CFRP) and coated with functionally graded polymeric material (FGPM) are investigated. The fundamental equations of a moderately-thick shell are established within the framework of Reddy’s higher-order shear deformation theory (HSDT). The material model is derived by combining the conventional micro-mechanical CFRP model with the hybrid FGPM model. Micro-crack damage in CFRP core is included via the damage variables. The buckling compressive stresses of the shells exposed to the thermal environment are obtained by the Galerkin’s method. The solutions reveal that the lay-up sequence of the laminas and the thickness ratio of the FGPM coating to CFRP core have significant influence on the computed results. The variation of the buckling loads with respect to the content of carbon fiber and distributed profile of the FGPM components follows some nonlinear laws. The structural instability induced by damages appear to be more remarkable with the increased shell thickness. However, this effect can be reduced by optimizing the ply angles of the stacking laminas. More factors, such as geometric parameters, numbers of fiber layers, lamina stacking sequences, damage, material properties and thermal loads, are also discussed in detail.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-09-12T02:33:43Z
      DOI: 10.1142/S0219455419500160
       
  • Vector Form Intrinsic Finite Element Method for Analysis of Train–Bridge
           Interaction Problems Considering The Coach-Coupler Effect
    • Authors: Y. F. Duan, S. M. Wang, J. D. Yau
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, the vector form intrinsic finite element (VFIFE) method is presented for analysis the train–bridge systems considering the coach-coupler effect. The bridge is discretized into a group of mass particles linked by massless beam elements and the multi-body coach with suspension systems is simulated as a set of mass particles connected by parallel spring-dashpot units. Then the equation of motion of each mass particle is solved individually and the internal forces induced by pure deformations in the massless beam elements are calculated by a fictitious reverse motion method, in which the structural stiffness matrices need not be updated or factorized. Though the vector-form equations resulting from the VFIFE method cannot be used to compute the structural frequencies by the eigenvalue approach, this study proposes a numerical free vibration test to identify the bridge frequencies for evaluating the bridge damping. Numerical verifications demonstrate that the present VFIFE method performs as accurately as previous numerical ones. The results show that the couplers play an energy-dissipating role in reducing the car bodies’ response due to the bridge-induced resonance, but not in their response due to the train-induced resonance because of the bridge’s intense vibration. Meanwhile, a dual-resonance phenomenon in the train–bridge system occurs when the coach-coupler effect is considered in the vehicle model.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-09-10T03:01:02Z
      DOI: 10.1142/S0219455419500147
       
  • Analytical and Experimental Flutter Analysis of a Typical Wing Section
           Carrying a Flexibly Mounted Unbalanced Engine
    • Authors: A. S. Mirabbashi, A. Mazidi, M. M. Jalili
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, both experimental and analytical flutter analyses are conducted for a typical 5-degree of freedon (5DOF) wing section carrying a flexibly mounted unbalanced engine. The wing flexibility is simulated by two torsional and longitudinal springs at the wing elastic axis. One flap is attached to the wing section by a torsion spring. Also, the engine is connected to the wing by two elastic joints. Each joint is simulated by a spring and damper unit to bring the model close to reality. Both the torsional and longitudinal motions of the engine are considered in the aeroelastic governing equations derived from the Lagrange equations. Also, Peter’s finite state model is used to simulate the aerodynamic loads on the wing. Effects of various engine parameters such as position, connection stiffness, mass, thrust and unbalanced force on the flutter of the wing are investigated. The results show that the aeroelastic stability region is limited by increasing the engine mass, pylon length, engine thrust and unbalanced force. Furthermore, increasing the damping and stiffness coefficients of the engine connection enlarges the stability domain.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-09-07T04:05:24Z
      DOI: 10.1142/S0219455419500135
       
  • Vibration Frequency Analysis of Beam–Ring Structure for Circular
           Deployable Truss Antenna
    • Authors: R. Q. Wu, W. Zhang, K. Behdinan
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The circular truss antenna of the large aperture is considered to be a flexible structure which may cause vibration in space and may affect its performance. The frequency analysis of the circular truss antenna is an important problem for understanding its vibration mechanism. In this paper, we investigate the frequency characteristics of a beam–ring structure which is proposed for the first time to model the circular truss antenna in the case of the antenna expended and locked. Based on describing the displacements of the beam–ring system in detail, the kinetic energy and potential energy are calculated. The partial differential governing equations of motion and boundary conditions for the beam–ring structure are derived by Hamilton principle. From the linear parts of the governing equations of motion and the corresponding boundary conditions, the linear frequencies of the beam–ring structure are theoretically obtained. The effects of the physical parameters on the frequency characteristics of the beam–ring structure are studied, which are further verified by the numerical results. The finding phenomena of this paper are helpful for designing and controlling the beam–ring structure such as the circular truss antenna.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-27T06:13:15Z
      DOI: 10.1142/S0219455419500123
       
  • Preface: Special Issue on Structural Assessment and Health Monitoring
    • Authors: Heung-fai Lam
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.

      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-21T08:52:52Z
      DOI: 10.1142/S0219455419020012
       
  • Generalized Second Moment of Areas of Regular Polygons for Ludwick Type
           Material and its Application to Cantilever Column Buckling
    • Authors: Joon Kyu Lee, Byoung Koo Lee
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This study deals with the generalized second moment of area (GSMA) of regular polygon cross-sections for the Ludwick type material and its application to cantilever column buckling. In the literature, the GSMA for the Ludwick type material has only been considered for rectangular, elliptical and superellipsoidal cross-sections. This study calculates the GSMAs of regular polygon cross-sections other than those mentioned above. The GSMAs calculated by varying the mechanical constant of the Ludwick type material for the equilateral triangle, square, regular pentagon, regular hexagon and circular cross-sections are reported in tables and figures. The GSMAs obtained from this study are applied to cantilever column buckling, with results shown in tables and figures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-21T07:06:30Z
      DOI: 10.1142/S021945541950010X
       
  • A Practical Wheel-Rail Interaction Element for Modeling
           Vehicle-Track-Bridge Systems
    • Authors: Quan Gu, Yongdou Liu, Wei Guo, Weiquan Li, Zhiwu Yu, Lizhong Jiang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A novel practical element is presented for simulating the vertical wheel-rail interaction (WRI) of vehicle-track-bridge (VTB) coupling systems. The WRI is time- and location-varying, which makes the simulation of the VTB system complicated. The new element simulates the WRI using a location dependent internal resisting force, which enables the finite element (FE) model of the VTB system to remain unchanged in analysis. This element is capable of simulating the nonlinear WRI, the rail irregularity and the ‘additional’ displacement of the rail. The ‘additional’ displacement is the extra displacement caused by the WRI besides that interpolated from the element nodal displacements, which is usually ignored by existing models, but may be non-negligible in some cases. The WRI element is implemented into a general FE software framework, OpenSees, and verified by the dynamic analysis of a simply-supported beam subjected to a moving sprung mass. Furthermore, a realistic VTB system with a moving four-wheel vehicle is investigated to evaluate the cases where the additional displacement and nonlinear WRI should be considered. Finally, using another realistic VTB system subjected to rail irregularities and earthquakes, the effects of rail irregularity and earthquake on the dynamic responses of the WRI system are studied and compared.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-21T07:06:28Z
      DOI: 10.1142/S0219455419500111
       
  • Nonlinear Whirling Motion of Monopile Offshore Wind Turbines Subjected to
           Harmonic and Seismic Base Excitations
    • Authors: Zhicheng Cai, Xiang Yuan Zheng
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The triggering mechanism and the vibration patterns of the nonlinear whirling motion of monopile offshore wind turbines subjected to unidirectional base excitations are investigated both theoretically and experimentally via a 64:1 scaled model of the prototype NREL-5MW monopile offshore wind turbine. For motion, two nonlinear coupled integro-differential equations containing cubic nonlinearities due to curvature and inertia are solved by both analytical and numerical methods. Harmonic and random seismic base excitations with different amplitudes and frequencies are considered in the analysis to understand the instability mechanism. Extensive shake table tests show that the experimental results have good qualitative agreements with the theoretical results, and as observed in eight load cases, the nonlinear whirling motions of nacelle do exist and tend to be induced by large harmonic excitations with structural resonant frequency.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-21T07:06:27Z
      DOI: 10.1142/S0219455419500093
       
  • Rigid-Mass Vehicle Model for Identification of Bridge Frequencies
           Concerning Pitching Effect
    • Authors: Judy P. Yang, Bo-Lin Chen
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The concept of vehicle-bridge interaction (VBI) was originally developed to investigate the dynamic behavior of bridges subjected to moving loads such as high-speed trains. In recent years, the VBI system was introduced to further explore the possibility of identifying bridge frequencies in order to monitor the health of bridges via the use of passing vehicles. Among the models of test vehicles, the sprung mass vehicle model with a single-degree-of-freedom vehicle body is the most common adopted one due to its simplicity. Nevertheless, for a test vehicle moving over the uneven pavement, the pitching effect arising from the vertical and rotational movements of the vehicle actually influences the identification of bridge frequencies. As such, a rigid-mass vehicle model is proposed in this work to improve the sprung mass vehicle model by including both vertical and rotational deflections. The analytical solutions to the rigid-mass VBI system are derived to verify the proposed model, and the numerical examples are provided to investigate the dynamic behavior of the VBI system subjected to road irregularity.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-20T04:14:56Z
      DOI: 10.1142/S0219455419500081
       
  • Seismic Interaction between a Lined Tunnel and a Hill under Plane SV Waves
           by IBEM
    • Authors: Zhongxian Liu, Hai Zhang, Alexander Cheng, Chengqing Wu, Guogang Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper investigates the dynamic interaction between a lined tunnel and a hill under plane SV waves using the indirect boundary element method (IBEM), with the displacement and stress characteristics of the system presented in frequency domain. The IBEM has several unique advantages such as reducing calculation dimension, automatically satisfying the infinite radiation condition, etc. The numerical results indicated that the dynamic response of the tunnel–hill system is strongly dependent on incident wave characteristics, geometrical and material properties of the lined tunnel, as well as the topography of the hill. For a dimension ratio between the hill and tunnel of less than 10.0, the lined tunnel has large amplification or deamplification effect on the dynamic response of the hill. Correspondingly, the hill also greatly amplifies the displacement and stress concentration of the tunnel especially in the lower-frequency range, due to the complicated interference effect among the reflected waves and diffracted waves induced by the tunnel and hill. Also demonstrated is that the displacement and stress amplitude spectrums highly depend on the incident frequency and the space location, and there exist multiple peaks and troughs in the spectrum curve with the peaks usually appearing in the low-frequency range. Thus, for the seismic safety assessment of a hill slope or hill tunnel in practice, the dynamic interaction within the tunnel–hill system should be taken into consideration.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-13T09:38:10Z
      DOI: 10.1142/S0219455419500044
       
  • Critical Comparison of Bresse–Timoshenko Beam Theories for Parametric
           Instability in the Presence of Pulsating Load
    • Authors: Isaac Elishakoff, Florian Hache, Noël Challamel
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, we investigate parametric instability of Bresse–Timoshenko columns subjected to periodic pulsating compressive loads. The results are derived from three theories, namely the Bernoulli–Euler model for thin beams and two versions of the Bresse–Timoshenko model valid for thick beams: The truncated Bresse–Timoshenko model and the Bresse–Timoshenko model based on slope inertia. The truncated Bresse–Timoshenko model has been derived from asymptotic analysis, whereas the Bresse–Timoshenko model based on slope inertia is an alternative shear beam model supported by variational arguments. These models both take into account the rotary inertia and the shear effect. Simple supported boundary conditions are considered, so that the time-dependent deflection solution can be decomposed into trigonometric spatial functions. The instability domain in the load–frequency space is analytically characterized from a Meissner-type parametric equation. For small slenderness ratio, these last two Bresse–Timoshenko models coincide but for much higher slenderness ratio, the parametric instability regions in the load–frequency space shift to the left and widen them as compared to the Bernoulli–Euler model. The importance of these effects differs between the models.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-13T09:38:07Z
      DOI: 10.1142/S0219455419500068
       
  • Nonlinear Pull-In Instability of Strain Gradient Microplates Made of
           Functionally Graded Materials
    • Authors: R. Gholami, R. Ansari, H. Rouhi
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, the size-dependent nonlinear pull-in behavior of rectangular microplates made from functionally graded materials (FGMs) subjected to electrostatic actuation is numerically studied using a novel approach. The small scale effects are taken into account according to Mindlin’s first-order strain gradient theory (SGT). The plate model is formulated based on the first-order shear deformation theory (FSDT) using the virtual work principle. The size-dependent relations are derived in general form, which can be reduced to those based on different elasticity theories, including the modified strain gradient, modified couple stress and classical theories (MSGT, MCST and CT). The solution of the problem is arrived at by employing an efficient matrix-based method called the variational differential quadrature (VDQ). First, the quadratic form of the energy functional including the size effects is obtained. Then, it is discretized by the VDQ method using a set of matrix differential and integral operators. Finally, the achieved discretized nonlinear equations are solved by the pseudo arc-length continuation method. In the numerical results, the effects of material length scale parameters, side length-to-thickness ratio and FGM’s material gradient index on the nonlinear pull-in instability of microplates with different boundary conditions are investigated. A comparison is also made between the predictions by the MSGT, MCST and CT.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-13T09:38:07Z
      DOI: 10.1142/S021945541950007X
       
  • 3D Vibration Analysis of Combined Shells of Revolution
    • Authors: Jae-Hoon Kang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A three-dimensional (3D) method of analysis is presented for determining the natural frequencies and the mode shapes of combined hemispherical–cylindrical shells of revolution with and without a top opening by the Ritz method. Instead of mathematically two-dimensional (2D) conventional thin shell theories or higher-order thick shell theories, the present method is based upon the 3D dynamic equations of elasticity. Mathematically, minimal or orthonormal Legendre polynomials are used as admissible functions in place of ordinary simple algebraic polynomials which are usually applied in the Ritz method. The analysis is based upon the circular cylindrical coordinates instead of the shell coordinates which are normal and tangent to the shell mid-surface. Strain and kinetic energies of the combined shell of revolution with and without a top opening are formulated, and the Ritz method is used to solve the eigenvalue problem, thus yielding upper bound values of the frequencies by minimizing the frequencies. As the degree of the Legendre polynomials is increased, frequencies converge to the exact values. Convergence to four-digit exactitude is demonstrated for the first five frequencies. Numerical results are presented for the combined shells of revolution with or without a top opening, which are completely free and fixed at the bottom of the combined shells. The frequencies from the present 3D Ritz method are compared with those from 2D thin shell theories by previous researchers. The present analysis is applicable to very thick shells as well as very thin shells.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-13T09:38:05Z
      DOI: 10.1142/S0219455419500056
       
  • Coupled Bi-Flexural–Torsional Vibration of Fluid-Conveying Pipes
           Spinning About an Eccentric Axis
    • Authors: Feng Liang, Xiao-Dong Yang, Wei Zhang, Ying-Jing Qian
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a dynamical model of a fluid-conveying pipe spinning about an eccentric axis. The coupled bi-flexural–torsional free vibration and stability are analyzed for such a doubly gyroscopic system. The partial differential equations of motions are derived by the extended Hamilton principle, and are then truncated by a 4-term Galerkin technique. The frequency and energy evolutions and representative mode shapes in the two transverse directions and torsional direction are investigated to unveil the essential dynamical attributes of the system. It is indicated that the stability of the present system mainly depends on spinning speed, flow velocity and eccentricity, while the torsional frequencies are almost immune to the flow velocity. The pipe reveals ‘traveling-wave’ modal vibrations in both transverse directions, and a general ‘standing-wave’ modal vibration in the torsional direction.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-13T09:38:05Z
      DOI: 10.1142/S0219455419500032
       
  • Dynamics and Stability of Non-planar Rigid Rotor Equipped with Two
           Ball-Spring Autobalancers
    • Authors: Mousa Rezaee, Mir Mohammad Ettefagh, Reza Fathi
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Recently, a new type of automatic ball balancer (ABB), called the ball-spring autobalancer (AB), has been proposed, which substantially eliminates the drawbacks of the traditional ABBs. In previous studies, the dynamics of the Jeffcott planar rotor equipped with ball-spring AB has been investigated. In the Jeffcott model, it is assumed that the ABB is located on the plane of the unbalance disk. However, for the non-planar rigid rotor with distributed imbalances, out-of-plane motions may occur, and the Jeffcott model becomes unreliable as the tilting motion cannot be explained. To this end, the aim of this paper is to analyze the capability of the ball-spring AB in balancing non-planar rotors and to reconfirm its pre-claimed advantages over the traditional ABBs for balancing non-planar rotors. To start, the mathematical model of the rigid rotor with two ball-spring ABs is established, based on which the nonlinear equations of motion are derived. Then, the system time responses are computed numerically and the balanced stable regions are acquired by the Lyapunov’s first method. The results of this study show that the ball-spring ABs can balance the non-planar rotors and the tilting motion does not impair the pre-claimed advantages of the ball-spring AB.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-08-06T08:06:07Z
      DOI: 10.1142/S0219455419500019
       
  • Stability Analysis of a Simple Strut with Elastic Springs Through
           Sensitivity Surfaces and Gradients
    • Authors: Mario Uroš, Damir Lazarević, Marija Demšić, Josip Atalić
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The global elastic stability of a strut supported by three inclined springs is studied using the exact displacement geometry. The discrete phenomenological model in the theory of stability, described by Thompson and Gaspar, exhibits different postbuckling behaviors, depending on the initial geometry for large imperfections, and this has various applications in engineering. Using the total potential energy method, a system of nonlinear algebraic equations is derived for the nondissipative system. The arc length method is adopted to solve the system of nonlinear equations, considering the stability of equilibrium points at each position, while detecting and traversing the critical points with the possibility of intervention. The characteristic equilibrium paths and their corresponding trajectories are shown and compared with the asymptotic solutions at the first critical point. A parametric analysis is performed, and sensitivity surfaces are constructed for several initial positions of the springs, represented by the initial angle in the horizontal plane. A wide range of independent imperfections with large amplitudes in two directions is considered. The concept of load capacity gradient functions of sensitivity surfaces is introduced and used to qualitatively and quantitatively analyze the stability behavior of the system located far away from the initial position. A few interesting observations and conclusions are obtained from the sensitivity analysis of a simple strut in the postcritical region. The critical combinations of imperfections for each static system are determined through analysis of the gradients. Further, the “stable” and “unstable” regions of the sensitivity surfaces are identified, with some observations made. Finally, the applications of load capacity gradient functions in structural optimization and form findings are reviewed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-07-16T09:11:33Z
      DOI: 10.1142/S0219455418501614
       
  • Capacity Estimation of Beam-Like Structures Using Substructural Method
    • Authors: Shojaeddin Jamali, Tommy HT Chan, Ki-Young Koo, Andy Nguyen, David P Thambiratnam
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Evaluating the performance of beam-like structures in terms of their current boundary conditions, stiffness and modal properties can be challenging as the structures behave differently from their designed conditions due to aging. The purpose of the current study is to determine the flexural rigidity of beam-like structures when their support conditions are not fully understood. A novel optimization scheme is proposed for estimation of the flexural stiffness and the capacity of the beam-like structures under moving loads. The proposed method is applied to various profiles of the beams made of different materials with unknown boundary conditions, and the effects of damage, excitation and optimization algorithm are rigorously investigated. The results of the numerical and experimental studies showed that the proposed substructural bending rigidity identification (SBI) method can correctly assess the in-service flexural stiffness, fixity of the boundary condition and the load-carrying capacity. This technique can be considered as a cost-effective method for periodic monitoring, load rating and model updating of the beam-like structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-07-16T09:11:32Z
      DOI: 10.1142/S0219455418501626
       
  • Structural Deterioration Detection Using Enhanced Autoregressive Residuals
    • Authors: Benyamin Monavari, Tommy H. T. Chan, Andy Nguyen, David P. Thambiratnam
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a study on detecting structural deterioration in existing buildings using ambient vibration measurements. Deterioration is a slow and progressive process which reduces the structural performance, including load-bearing capacity. Each building has unique vibration characteristics which change in time due to deterioration and damage. However, the changes due to deterioration are generally subtler than the changes due to damage. Examples of deterioration include subtle loss of steel-concrete bond strength, slight corrosion of reinforcement and onset of internal cracks in structural members. Whereas damage can be defined as major sudden structural changes, such as major external cracks of concrete covers. Herein, a deterioration detection method which uses structural health monitoring (SHM) data is proposed to address the deterioration assessment problem. The proposed novel vibration-based deterioration identification method is a parametric-based approach, incorporated with a nonparametric statistical test, to capture changes in the dynamic characteristics of structures. First, autoregressive (AR) time-series models are fitted to the vibration response time histories at different sensor locations. A sensitive deterioration feature is proposed for detecting deterioration by applying statistical hypotheses of two-sample [math]-test on the model residuals, based on which a function of the resulting [math]-values is calculated. A novel AR model order estimation procedure is proposed to enhance the sensitivity of the method. The performance of the proposed method is demonstrated through comprehensive simulations of deterioration at single and multiple locations in finite element models (FEM) of 3- and 20-storey reinforced concrete (RC) frames. The method shows a promising sensitivity to detect small levels of structural deterioration prior to damage, even in the presence of noise.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-07-16T09:11:31Z
      DOI: 10.1142/S0219455418501602
       
  • Effect of Added Mass on Wind-Induced Vibration of a Circular Flat Membrane
           by Wind Tunnel Tests
    • Authors: Yu Zhou, Yuanqi Li, Akihito Yoshida
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Flexible roof structures, such as membranes, are sensitive to wind action due to their flexibility and light weight. Previously, the effect of added mass on the vibration frequency of membrane structures has been experimentally tested. However, the effect of added mass on wind-induced vibration remains unclear. The purpose of this paper is to investigate the effect of added mass on the wind-induced vibration of a circular flat membrane based on wind tunnel tests. First, wind tunnel tests were conducted to obtain wind pressure distribution from the rigid model and wind-induced vibration from the aeroelastic model of a circular flat membrane. Secondly, a dynamic finite element analysis for the proposed added mass model was conducted to obtain the wind-induced vibration of the membrane structure. Then, with the wind pressure distribution obtained from the rigid model tests, dynamic analysis was conducted either with or without consideration of the effect of added mass. According to the dynamic analysis results and the wind tunnel test results, it is clear that considering the effect of added mass in dynamic analysis can significantly improve the accuracy of a wind-induced response. Such an effect is more significant at the windward than the central zone. The inclusion of added mass can result in a larger displacement response as wind velocity increases but a smaller response as the prestress level increases.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-19T10:44:43Z
      DOI: 10.1142/S0219455418501560
       
  • Theoretical 3D Model of Thermoelastic Damping in Laminated Rectangular
           Plate Resonators
    • Authors: Shoubin Liu, Jingxuan Ma, Xianfeng Yang, Yuxin Sun, Jialing Yang, Xin Wang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Thermoelastic damping (TED) can lead to energy loss in microscale resonators, which is an intrinsic mechanism. To minimize the energy loss, it is required to determine the TED of resonators. Laminated plate resonators are commonly used in practice. However, existing researches on TED of the laminated resonators use mainly the one-dimensional (1D) heat conduction model, as the 3D governing equation is complicated, which cannot show the influences of boundary conditions along the supporting edges. In this paper, the governing equation of thermoelastic problems with 3D heat conduction was established for the out-of-plane vibration of the laminated rectangular plate. The analytical expression of the TED was derived using its physical meaning, namely, the ratio of the energy dissipated to the total elastic strain energy stored per cycle of vibration. It was found that the size and shape of the plate affect crucially the TED. The values of TED for higher-order vibration modes were also evaluated. Most importantly, the influences of supporting conditions and heat conduction conditions along the four edges were studied, which is the first report for laminated plates. The present approach can provide guidance for the design of high-quality bilayered resonators.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-19T10:44:42Z
      DOI: 10.1142/S0219455418501584
       
  • Structural Damage Identification Based on Strain Frequency Response
           Functions
    • Authors: Fariba Shadan, Faramarz Khoshnoudian, Akbar Esfandiari
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Damage identification using the sensitivity of the dynamic characteristics of the structure of concern has been studied considerably. Among the dynamic characteristics used to locate and quantify structural damages, the frequency response function (FRF) data has the advantage of avoiding modal analysis errors. Additionally, previous studies demonstrated that strains are more sensitive to localized damages compared to displacements. So, in this study, the strain frequency response function (SFRF) data is utilized to identify structural damages using a sensitivity-based model updating approach. A pseudo-linear sensitivity equation which removes the adverse effects of incomplete measurement data is proposed. The approximation used for the sensitivity equation utilizes measured natural frequencies to reconstruct the unmeasured SFRFs. Moreover, new approaches are proposed for selecting the excitation and measurement locations for effective model updating. The efficiency of the proposed method is validated numerically through 2D truss and frame examples using incomplete and noise polluted SFRF data. Results indicate that the method can be used to accurately locate and quantify the severity of damage.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-19T10:44:41Z
      DOI: 10.1142/S0219455418501596
       
  • L1 Regularized Model Updating for Structural Damage Detection
    • Authors: Yu-Han Wu, Xiao-Qing Zhou
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Model updating methods based on structural vibration data have been developed and applied to detecting structural damages in civil engineering. Compared with the large number of elements in the entire structure of interest, the number of damaged elements which are represented by the stiffness reduction is usually small. However, the widely used [math] regularized model updating is unable to detect the sparse feature of the damage in a structure. In this paper, the [math] regularized model updating based on the sparse recovery theory is developed to detect structural damage. Two different criteria are considered, namely, the frequencies and the combination of frequencies and mode shapes. In addition, a one-step model updating approach is used in which the measured modal data before and after the occurrence of damage will be compared directly and an accurate analytical model is not needed. A selection method for the [math] regularization parameter is also developed. An experimental cantilever beam is used to demonstrate the effectiveness of the proposed method. The results show that the [math] regularization approach can be successfully used to detect the sparse damaged elements using the first six modal data, whereas the [math] counterpart cannot. The influence of the measurement quantity on the damage detection results is also studied.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-19T10:44:39Z
      DOI: 10.1142/S0219455418501572
       
  • Nonuniform Heat Effects on Buckling of Laminated Composite Beam:
           Experimental Investigations
    • Authors: Nivish George, P. Jeyaraj
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The influence of nonuniform heating on the critical buckling temperature of laminated glass-epoxy composite beam has been investigated experimentally with the help of a novel experimental setup. The beam is numerically investigated using nonlinear finite element analysis. An initial geometric imperfection is introduced to the modeled geometry in numerical technique to have an experimental–numerical comparison of temperature-deflection plot. The results indicate that the critical buckling temperature of a uniformly heated beam has a significant difference in comparison to the nonuniformly heated beam and it depends on the heating source location and the resulting temperature distribution along the length direction of the beam.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-13T01:15:59Z
      DOI: 10.1142/S0219455418501535
       
  • Experimental Study on the Effect of Temperature on Modal Frequencies of
           Bridges
    • Authors: Limin Sun, Yi Zhou, Zhihua Min
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This study investigates the relationship between the temperature and the modal frequencies of bridges through a series of model experiments using a concrete continuous beam bridge model and a steel cable-stayed bridge model in a controlled-temperature chamber. The experimental results show that, for a given boundary condition and in the absence of freezing, a change in temperature affects the structural frequencies of the bridge as it alters the elastic modulus of the bridge materials. The structural frequency tends to linearly decrease with increasing temperature and with the decrease in the frequency of steel bridges smaller than that of concrete bridges. For the particular case of wet concrete bridges, the temperature dependencies of modal frequencies vary dramatically near the freezing point, which is attributable to the freeze–thaw process of concrete pore water. The effect of air humidity on structural frequency is less significant than that of temperature when the boundary conditions remain unchanged. Furthermore, temperature changes may alter the boundary conditions of bridges, thereby affecting the structural frequencies.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-13T01:15:59Z
      DOI: 10.1142/S0219455418501559
       
  • Variational Iteration Approach for Flexural Vibration of Rotating
           Timoshenko Cantilever Beams
    • Authors: Yanfei Chen, Shaohua Dong, Zhipeng Zang, Qi Zhang, Juan Zhang, Xiaoben Liu, Hong Zhang, Fangyu Lou, Chuan Ao
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper is concerned with the flexural vibration analysis of rotating Timoshenko beams by using the variational iteration method (VIM). Accurate natural frequencies and mode shapes of rotating Timoshenko beams under various rotation speeds and rotary inertia are obtained. The VIM solutions are verified by comparing with some existing results in the literature as well as validated from a comparison study with experimentally measured ones. High accuracy and efficiency of VIM are demonstrated by the use of only a small number of iteration steps required for convergence of the first to the tenth mode frequencies of rotating Timoshenko beam.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-13T01:15:58Z
      DOI: 10.1142/S0219455418501547
       
  • Experimental Study on High-Performance Buckling-Restrained Braces with
           Perforated Core Plates
    • Authors: Liang-Jiu Jia, Yang Dong, Hanbin Ge, Kana Kondo, Ping Xiang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The compressive deformation is mainly contributed by axial compressive deformation and high-order in-plane and out-of-plane global buckling deformation for conventional buckling-restrained braces (BRBs). A novel type of all-steel BRBs with perforated core plates, termed as perforated BRBs (PBRBs), are proposed in this study, where shear deformation can occur in addition to the aforementioned deformations in a conventional BRB under compression. Experimental study was carried out using five specimens with different configurations of holes under cyclic loading. Stable hysteretic properties, high ductility, and energy dissipation capacity were obtained for the PBRBs. The effects of two parameters, i.e. the slenderness ratio of the chord and hole spacing factor defined as the ratio of the hole length to the hole spacing, on seismic performance of the specimens were investigated. The compressive deformation mechanisms of the PBRBs were further investigated through a numerical study. The compressive deformation was found to be composed of axial compressive deformation, flexural deformation owing to in-plane and out-of-plane global buckling, and in-plane shear deformation of the latticed core plate.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:33Z
      DOI: 10.1142/S0219455419400042
       
  • Operational Modal Analysis and Bayesian Model Updating of a Coupled
           Building
    • Authors: Jun Hu, Jia-Hua Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper reports the step-by-step procedures of a full-scale ambient vibration test and the corresponding modal identification and Bayesian structural model updating of a coupled building. The building is characterized as a combination of a main part and a complementary part connected together by corridors in between. Compared with the main part, the volume of the complementary part is much smaller. Therefore, the influence on the dynamic properties of the complementary part from its counterpart is expected. To capture the dynamic properties of the coupled building, a 21-setup ambient vibration test was designed to cover all the degrees of freedom (DOFs) of interest. The modal parameters of each setup were identified following the frequency domain decomposition (FDD) method and the partial mode shapes from different setups were assembled following a least-squares method. To determine the stiffness of the linkage between the two parts, the coupled building was simulated with two linked shear buildings and updated utilizing the Markov chain Monte Carlo (MCMC)-based Bayesian model updating method. The identified modal parameters revealed interesting features about the coupled effects between the main part and complementary part and were discussed in detail. The good match between the model-predicted and identified modal parameters verified the validity of proposed shear building model. This study provides valuable experience in the area of structural model updating and structural health monitoring.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:33Z
      DOI: 10.1142/S0219455419400121
       
  • Second Harmonic Generation of Guided Wave at Crack-Induced Debonding in
           FRP-Strengthened Metallic Plates
    • Authors: Yi Yang, Ching-Tai Ng, Andrei Kotousov
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The use of fiber-reinforced polymer (FRP) has been widely recognized to be an effective and economical way to strengthen existing structures or repair damaged structures for extending their service life. This study investigates the feasibility of using nonlinear guided wave to monitor crack-induced debonding in FRP-strengthened metallic plates. The study focusses on investigating the nonlinear guided wave interaction with the crack-induced debonding. A three-dimensional (3D) finite element (FE) model is developed to simulate the crack-induced debonding in the FRP-strengthened metallic plates. The performance of using fundamental symmetric ([math] and anti-symmetric ([math] modes of guided wave as incident wave in the second harmonic generation at the crack-induced debonding is investigated in detail. It is found that the amplitude of the second harmonic and its variation with different damage sizes are very different when using [math] and [math] guided wave as the incident wave, respectively. The results suggest that it is possible to detect potential damage and distinguish its type based on the features of the generated second harmonic.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:32Z
      DOI: 10.1142/S0219455419400066
       
  • Master [math]-[math] Curve-Based Fatigue Life Assessment of Steel Bridges
           Using Finite Element Model and Field Monitoring Data
    • Authors: X. W. Ye, Y. H. Su, T. Jin, B. Chen, J. P. Han
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The accuracy of fatigue life assessment for the welded joint in a steel bridge is largely dependent on an appropriate [math]-[math] curve. In this paper, a master [math]-[math] curve-based fatigue life assessment approach for the welded joint with an open-rib in orthotropic steel bridge deck is proposed based on the finite element model (FEM) and field monitoring data from structural health monitoring (SHM) system. The case studies on fatigue life assessment by use of finite element analysis (FEA) for constant-amplitude cyclic loading mode and field monitoring data under variable-amplitude cyclic loading mode are addressed. In the case of FEA, the distribution of structural stress at fatigue-prone weld toe is achieved using 4-node shell element model and then transformed into equivalent structural stress by fracture mechanics theory. The fatigue life of the welded joint is estimated with a single master [math]-[math] curve in the form of equivalent structural stress range versus the cycles to failure. In the case of monitoring data-based fatigue life assessment, the daily history of structural stress at diaphragm to U-rib is derived from the raw strain data measured by the instrumented fiber Bragg grating (FBG) sensors and transformed into equivalent structural stress. The fatigue life of the investigated welded joint is calculated by cyclic counting method and Palmgren–Miner linear damage cumulative rule. The master [math]-[math] curve method provides an effective fatigue life assessment process, especially when the nominal stress is hard to be defined. A single master [math]-[math] curve will facilitate to solve the difficulty in choosing a proper [math]-[math] curve which is required in the traditional fatigue life assessment methods.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:31Z
      DOI: 10.1142/S0219455419400133
       
  • Effect of Column Base Behavior on Seismic Performance of Multi-Story Steel
           Moment Resisting Frames
    • Authors: Yao Cui, Fengzhi Wang, Satoshi Yamada
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Column base is one of the most important elements of steel structures. Exposed column base is commonly used in low-to-medium-rise steel moment resisting frames because of better constructability and low cost. To study the effect of exposed column base behavior on the seismic behavior of low-to-medium-rise steel moment resisting frames, a four-story, four-bay steel moment frame is studied by the nonlinear time history analysis. In the numerical analysis, two types of column base connections (rigid and semi-rigid) are considered. The width–thickness ratio of column and stiffness ratio of column base to column are chosen as the analysis parameters. The characteristics of structural responses, hysteresis loops, and the distribution of plastic energy dissipation are compared. It indicates that the collapse margin ratio is significantly increased when the exposed column base behavior is considered for the moment resisting frames with large width–thickness ratio. Moreover, if the column base connection is allowed to rotate and transfer a portion of the moment, the demand of plastic deformation capacity of steel columns is reduced, then subsequently strength deterioration caused by the local buckling at the bottom of column could be avoided. Also, the whole structure has a better ductility, the ability of plastic deformation and energy absorbance of the moment resisting frame under earthquake are therefore enhanced. The structure with the semi-rigid column base connection has larger potential to avoid the structural collapse caused by the local buckling of first-story columns.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:31Z
      DOI: 10.1142/S0219455419400078
       
  • Neutral Axis-Based Health Monitoring and Condition Assessment Techniques
           for Concrete Box Girder Bridges
    • Authors: Ye Xia, Peng Wang, Limin Sun
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The neutral axis position is considered as a potential parameter of early abnormal and long term performance for flexural members of structures. This paper is to propose the Neutral Axis Indicator (NA) based on strain measurements, to evaluate the behavior of NA, and to investigate challenges associated with the neutral axis for structural health monitoring purpose. A numerical example of a simply supported reinforced concrete (RC) beam was first developed and analyzed followed by an experimental study for further verification. With the aim of application to real bridges, a case study was conducted on Gantao River Bridge, a typical concrete box girder bridge, for detailed analysis using field data. The numerical and experimental examples, as well as field tests, aim to figure out: (1) the sensitivity of NA to structural damages, especially at early age; (2) stability and uncertainty of NA using field data; (3) capability of NA on detecting abrupt and slowly changing structural degradation. The results show that: NA takes on good index accuracy and damage sensitivity on numerical and experimental cases; NA tends to keep constant during linear elastic phase, while responses quickly and sharply to nonlinear behaviors such as concrete cracking and hardening; and NA is a potentially reliable indicator both to capture nonlinear performance and to detect minute damage. Additionally, the uncertainty of multiple disturbing effects can be mostly eliminated through statistical analysis. Thus, it can be employed effectively in condition assessment of concrete box girder bridges for long-term health monitoring.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:30Z
      DOI: 10.1142/S0219455419400157
       
  • Dynamic Capacity Reduction of Railway Prestressed Concrete Sleepers Due to
           Surface Abrasions Considering the Effects of Strain Rate and Prestressing
           Losses
    • Authors: Chayut Ngamkhanong, Dan Li, Alex M. Remennikov, Sakdirat Kaewunruen
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In reality, railway prestressed concrete sleepers frequently experience significant aggressive loading conditions and harsh environments. Especially in sharp curves, lateral loading of train wheels in combination with incompressible hydraulic pressure aggravates the lateral oscillation and abrades the surface of sleepers right underneath the rail seats. Many investigators in the past have proposed various material models to improve abrasive resistance characteristics, but those have been mostly applied to the new products using novel materials such as fiber-reinforced concrete. On the other hand, prestressed concrete sleepers have been used for over 50 years and they have become worn over time. This paper highlights the dynamic capacity evaluation of worn sleepers, which will lead to predictive models that could be realistically applied to asset management of railway lines. This paper presents an investigation into the structural capacity reduction in worn railway prestressed concrete sleepers considering the effects of strain rate and loss of prestressing steel. RESPONSE2000 has been used to evaluate the residual dynamic capacity based on the modified compression field theory. Unprecedented parametric studies have been carried out to determine the influences of uniform and gradient prestress losses on prestressed concrete capacity. The study results exhibit the level of wear and tear, which is critical to the dynamic integrity of sleepers required for immediate replacement. The outcome of this study will help improve the practical maintenance and monitoring technology in railway industry.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:30Z
      DOI: 10.1142/S0219455419400017
       
  • Incremental Analysis for Seismic Assessment of Bridge with Functional
           Bearing System Subjected to Near-Fault Earthquake
    • Authors: Li-Wei Liu, Kuang-Yen Liu, Deng-Gang Huang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A bridge with the functional bearing system, where sticking-sliding mechanism of rubber bearing reduces the force transmission between the substructure and the superstructure, shows viscoelastoplastic behavior. In the present paper, we show a simplified two-degree-of-freedom (2DOF) model for a bridge with the bearing system containing Coulomb’s friction element that displays mechanical behavior including the sticking (viscoelastic) and the sliding (viscoplastic) modes and we arrange its mathematical formulation into a two-phase framework which is a well-implemented form for incremental analysis. Solutions of the two-phase system are explored thoroughly and the exact solution of on-phase under piecewise constant input is obtained. Furthermore, we discuss on–off switching criteria of the bridge bearing system and propose an algorithm, including off-phase (viscoelastic) module, on-phase (viscoplastic) module, pull-back module, admissible condition, and straining condition, to simulate responses of the bridge bearing system. Based on the proposed algorithm, the assessment of the bridge with the functional bearing system which undergoes the near-fault earthquakes was made by investigation of the influence of five kinds of design parameters.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:29Z
      DOI: 10.1142/S0219455419400030
       
  • Experimental Verification of the Statistical Time-Series Methods for
           Diagnosing Wind Turbine Blades Damage
    • Authors: Hesheng Tang, Suqi Ling, Chunfeng Wan, Songtao Xue
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents an experimental verification of the statistical time-series methods, which utilize adapted frequency response ratio (FRR), autoregressive (AR) model parameter and AR model residual as performance characteristics, for diagnosing the damage of wind turbine blades. Specifically, the statistical decision-making techniques are used to identify the status patterns from turbine vibration data. For experiments, a small-size, laboratory-used operating wind turbine structure is used. The performance of each method in diagnosing damages simulated by saw cut in three critical positions in the blade are assessed and compared. The experimental results show that these methods yielded a promising damage diagnosis capability in the condition monitoring of wind turbine.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:29Z
      DOI: 10.1142/S021945541940008X
       
  • Dynamic Response and Stability Analysis with Newton Harmonic Balance
           Method for Nonlinear Oscillating Dielectric Elastomer Balloons
    • Authors: Dafeng Tang, C. W. Lim, Ling Hong, Jun Jiang, S. K. Lai
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Subject to various pressure and voltage values, the deformation of a hyperelastic dielectric elastomer membrane may attain different stable and unstable equilibria. In this paper, the neo-Hookean material model is adopted to describe the hyperelastic behavior of a dielectric elastomer membrane. The effects of initial stretch ratio, pressure and voltage on the nonlinear free vibration of a spherical dielectric elastomer balloon are investigated qualitatively and quantitatively. Through a linear stability analysis of the equilibrium states, the safe regime of initial stretch ratio for the deformation of dielectric elastomer balloon is confined. Under specific static driving pressure and voltage, the system oscillates about the stable equilibrium and there is no oscillation in the neighborhood of the unstable equilibrium. Besides, the critical pressure and voltage values are determined. Beyond the critical values, there is no periodic oscillation. Along with the stability analysis, complex dynamical behavior such as drastic change of output regime, sporadic instability and sudden bifurcations can be predicted. By applying the Newton Harmonic Balance (NHB) method for quantitative analysis, the frequency response can be readily predicted. It is found that the nonlinear free vibration frequency decreases with increasing initial stretch ratio and control parameters (pressure and voltage).
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:28Z
      DOI: 10.1142/S0219455418501523
       
  • Analysis of Anti-Collapse Performance of Beam–Column Substructure with
           Welded Flange-Bolted Web Connection in Minor-Axis Direction Under
           Different Span Ratios
    • Authors: Zhong Weihui, Song Xiaoyan, Ma Baoqian
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The failure modes, mechanical properties, and resistance mechanisms of beam–column substructures with welded flange-bolted web connection in the minor-axis direction under different span ratios (1:0.6, 1:1.0, 1:1.4) were compared and analyzed under the condition of progressive collapse. The beam–column substructures included three columns and two beams, and monotonic static loading tests were conducted using the alternate load path method. The test results indicated that the specimens began to fracture at the beam tension flange; and then, part of the main internal force was transferred by the bolts on the web, followed by buckling of the compression flange at the beam end. Finally, specimens were deactivated by the shear failure of bolt holes or the fracturing of the web and junction plate. The joint with a welded flange-bolted web connection was found to have high redundancy, with sufficient rotational capacity after the fracture of the tension flange. As a result of the effective pulling force between the beam and column, combined with sufficient rotation of the beam end, the remaining structure could give full play to the catenary effect, which would play a leading role in the later stage of large deformation. The deformation of the beam–column joint increased rapidly, which was conducive to the beam–column substructure to bear the load by collaboration between the beam and column. The simplified model and the numerical simulation are proved to be reliable by test results. The results of numerical simulations and analyses of anti-collapse performances of beam–column substructures under different span ratios showed that the large beam-span ratio was beneficial to the development of ultimate failure displacement of the substructure and increase the ratio of ultimate to initial failure load. The resistance provided by catenary mechanism also increased, and the short beam developed a better catenary effect than the long one.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:28Z
      DOI: 10.1142/S0219455419400054
       
  • Uncertainty Quantification of Load Effects under Stochastic Traffic Flows
    • Authors: He-Qing Mu, Qin Hu, Hou-Zuo Guo, Tian-Yu Zhang, Cheng Su
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Load effect characterization under traffic flow has received tremendous attention in bridge engineering, and uncertainty quantification (UQ) of load effect is critical in the inference process. Bayesian probabilistic approach is developed to overcome the unreliable issue caused by negligence of uncertainty of parametric and modeling aspects. Stochastic traffic load simulation is conducted by embedding the random inflow component into the Nagel–Schreckenberg (NS) model, and load effects are calculated by stochastic traffic load samples and influence lines. Two levels of UQ are performed for traffic load effect characterization: at parametric level of UQ, not only the optimal parameter values but also the associated uncertainties are identified; at model level of UQ, rather than using a single prescribed probability model for load effects, a set of probability distribution model candidates is proposed, and model probability of each candidate is evaluated for selecting the most suitable/plausible probability distribution model. Analytic work was done to give closed-form solutions for the expression involved in both parametric and model UQ. In the simulated examples, the efficiency and robustness of the proposed approach are firstly validated, and UQ are performed to different load effect data achieved by varying the structural span length under the changing total traffic volume. It turns out that the uncertainties of load effects are traffic-specific and response-specific, so it is important to conduct UQ of load effects under different traffic scenarios by using the developed approach.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:26Z
      DOI: 10.1142/S0219455419400091
       
  • Dynamic Property Evaluation of a Long-Span Cable-Stayed Bridge (Sutong
           Bridge) by a Bayesian Method
    • Authors: Yan-Chun Ni, Qi-Wei Zhang, Jian-Feng Liu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Modal identification aims at identifying the dynamic properties including natural frequency, damping ratio, and mode shape, which is an important step in further structural damage detection, finite element model updating, and condition assessment. This paper presents the work on the investigation of the dynamic characteristics of a long-span cable-stayed bridge-Sutong Bridge by a Bayesian modal identification method. Sutong Bridge is the second longest cable-stayed bridge in the world, situated on the Yangtze River in Jiangsu Province, China, with a total length of 2 088[math]m. A short-term nondestructive on-site vibration test was conducted to collect the structural response and determine the actual dynamic characteristics of the bridge before it was opened to traffic. Due to the limited number of sensors, multiple setups were designed to complete the whole measurement. Based on the data collected in the field tests, modal parameters were identified by a fast Bayesian FFT method. The first three modes in both vertical and transverse directions were identified and studied. In order to obtain modal parameter variation with temperature and vibration levels, long-term tests have also been performed in different seasons. The variation of natural frequency and damping ratios with temperature and vibration level were investigated. The future distribution of the modal parameters was also predicted using these data.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:24Z
      DOI: 10.1142/S0219455419400108
       
  • Discrete Tangent Stiffness Estimation Method for Pseudo Dynamic Test
    • Authors: Liang Huang, Cheng Chen, Tong Guo, Menghui Chen
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In pseudo dynamic (PSD) test, researchers have long recognized the importance and potential benefits of utilizing the tangent stiffness of experimental specimen to correct the restoring force and analyze the energy error. However, improving accuracy and efficiency of the instantaneous stiffness estimation still presents a challenge. Based on the theory of discrete curve parameter recognition and the geometrical analysis approach, this paper proposes a discrete tangent stiffness estimation (DTSE) method to estimate the instantaneous tangent stiffness of a single degree of freedom (SDOF) experimental specimen. For different magnitudes of measurement noise, the proposed method can adaptively select and retain a series of latest valid data and ignore outdated information, of which the advantage is highly improving the accuracy and promptness of instantaneous stiffness estimation. The numerical study shows that the DTSE method has better accuracy and promptness of tangent stiffness estimation when compared with other existing methods. In a PSD test involving a sliding isolator, the DTSE method is utilized to analyze the cumulative energy error, the result of which shows the cumulative energy error is negative and decreases gradually. The analysis of experimental results demonstrates that the undershooting error of actuator added extra energy into the PSD testing system. Thus, the proposed method provides a desirable solution to instantaneous stiffness estimation.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:23Z
      DOI: 10.1142/S0219455419400145
       
  • Damage Identification of Periodically-Supported Structures Following the
           Bayesian Probabilistic Approach
    • Authors: Tao Yin, Hong-ping Zhu, Shao-jun Fu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a probabilistic damage identification methodology tailor-made for periodically-supported structures with finite-length. The free wave motion of a general periodically-supported structure with a single disorder is analyzed through the characteristic receptance approach, and the corresponding frequency characteristic equation is developed. In addition, a concept of nondimensional frequency is introduced, and the sensitivity matrix of the nondimensional frequencies with respect to changes in stiffness of periodic cells is obtained by solving the frequency characteristic equation and utilizing the sensitivity analysis technique. Following the sensitivity-based identification equation with nondimensional frequency information, the probabilistic methodology for identifying the damage occurring in the periodically-supported structures is developed by implementing the Bayesian approach and the Markov chain Monte Carlo (MCMC) simulation with the Metropolis–Hasting sampling algorithm. The validity of the proposed methodology is demonstrated by both numerical simulations for a periodically-supported flanged pipeline example and experimental case studies conducted for a multi-span aluminum beam model endowed with bolted connections in the laboratory.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:21Z
      DOI: 10.1142/S021945541940011X
       
  • Performance of Steel-Reinforced Concrete-Filled Stainless Steel Tubular
           Columns at Elevated Temperature
    • Authors: Qinghua Tan, Leroy Gardner, Linhai Han
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Steel-reinforced concrete-filled stainless steel tubular (SRCFSST) columns combine the advantages of concrete-filled stainless steel tubular (CFSST) columns and steel-reinforced concrete (SRC) columns, resulting in excellent corrosion resistance, good economy, good ductility, and excellent fire resistance. Thus, SRCFSST columns have many potential structural engineering applications, especially in offshore structures. The performance of SRCFSST columns at elevated temperatures is investigated by finite element (FE) analysis in this paper. Firstly, FE models capable of capturing the full load-deformation response of structural members at elevated temperatures are developed and validated against relevant published tests on CFSST and SRC columns under fire conditions. Based on the validated FE models, the behavioral mechanisms of the SRCFSST columns under fire are explained by analysis of the sectional temperature distribution, typical failure modes, axial deformation versus time response, and load redistribution. Finally, the fire resistance of SRCFSST columns is evaluated in comparison to CFSST columns with equivalent sectional load-bearing capacity at ambient temperature or equivalent steel ratios. The results lay the foundation for the development of fire resistance design rules for SRCFSST columns.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-06-01T06:08:20Z
      DOI: 10.1142/S0219455419400029
       
  • Dynamic Stability of Rotating FG-CNTRC Cylindrical Shells under Combined
           Static and Periodic Axial Loads
    • Authors: Yasin Heydarpour, Parviz Malekzadeh
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The dynamic stability behavior of rotating functionally graded carbon nanotube reinforced composite (FG-CNTRC) cylindrical shells under combined static and periodic axial forces is investigated. The governing equations are derived based on the first-order shear deformation theory (FSDT) of shells. The initial mechanical stresses due to the steady state rotation of the shell are evaluated by solving the dynamic equilibrium equations. The equations of motion under different boundary conditions are discretized in the spatial domain and transformed into a system of Mathieu–Hill type equations using the differential quadrature method (DQM) together with the trigonometric series. The influences of both the initial mechanical stresses and Coriolis acceleration are considered. Then, the parametric resonance is analyzed and the dynamic instability regions are determined by employing the Bolotin’s first approximation. After validating the approach, the effects of rotational speed, Coriolis acceleration, carbon nanotubes (CNTs) distribution in the thickness direction, CNTs volume fraction, length and thickness-to-mean radius ratios on the principal dynamic instability regions are examined in detail.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-30T02:03:34Z
      DOI: 10.1142/S0219455418501511
       
  • Codimension-Two Bifurcation Analysis of a Vehicle Suspension System Moving
           Over Rough Surface
    • Authors: Chun-Cheng Chen, Shun-Chang Chang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper examines the dynamics of a nonlinear semi-active suspension system using a quarter-car model moving over rough road profiles. The bifurcation analysis of the nonlinear dynamical behavior of this system is performed. Codimension-two bifurcation and homoclinic orbits can be discovered in this system. When the external force of a road profile was added to this system as a parameter with a certain range of values, a strange attractor can be found using the numerical simulation. Finally, the Lyapunov exponent is adopted to identify the onset of chaotic motion and verify the bifurcation analysis.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-30T02:03:29Z
      DOI: 10.1142/S0219455418710128
       
  • Aeroelastic Stability Analysis of Aircraft Wings with High Aspect Ratios
           by Transfer Function Method
    • Authors: Jing Bo Duan, Zhong Yuan Zhang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A new method is developed for the aeroelastic stability analysis of a high-aspect-ratio wing based on the transfer function. First, the flutter governing equations for three types of wing elements including clear wing element, wing element with a control surface and that with an external store are, respectively, established by combining the corresponding bend-twist vibration model with the Theodrosen’s unsteady aerodynamic model. Then, in order to use the transfer function method, the element governing equations are processed by the Fourier transform and are formulated in a state-space form using state vector. Based on the finite element procedure, the global governing equations of the whole wing are obtained. Both the flutter velocity and flutter frequency are derived by solving a complex eigenvalue problem with the graphical approach. Additionally, the torsional divergence of the high-aspect-ratio wing is obtained by solving a real eigenvalue problem, which is a degenerated form of the wing flutter governing equations. Finally, illustrative examples are prepared to demonstrate the validity of the present method, which is insensitive to mesh density and does not require structural modal analysis for aeroelastic stability.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-25T09:54:40Z
      DOI: 10.1142/S021945541850150X
       
  • Damage Identification Using Wavelet Packet Transform and Neural Network
           Ensembles
    • Authors: Xiang Zhang, Renwen Chen, Qinbang Zhou
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This study presents a damage identification method that combines wavelet packet transforms (WPTs) with neural network ensembles (NNEs). The WPT is used to extract damage features, which are taken as the input vectors in the NNEs used for damage identification. An experiment was performed on a helicopter rotor blades structure to verify the proposed method. First, the vibration responses collected by different sensors are decomposed using the WPT. Second, the relative band energy of each decomposed frequency band is calculated and fused as the damage feature vectors. Third, two types of the NNEs are designed. One is based on the backward propagation neural networks (BPNNs) for detecting the damage locations and severities and the other one is based on the probabilistic neural network (PNN) to detect the damage types. Finally, the trained NNEs are employed in damage identification. From the identification outcomes, it is concluded that damage information can be extracted effectively by the WPT and the identification accuracy of the NNEs is better than that of individual neural networks (INNs).
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-25T09:54:38Z
      DOI: 10.1142/S0219455418501481
       
  • Nonlinear Free Flexural Vibration of Curvilinear Fibre Composite Laminates
           Using a Higher-Order Element
    • Authors: Manickam Ganapathi, Anand Venkatachari, Mohamed Haboussi, Arun Tom Mathew
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In the present work, the nonlinear free flexural vibration of thick curvilinear fiber composite laminates is investigated using a higher-order shear flexible eight-noded quadrilateral element developed considering the variation of in-plane and transverse displacement through the thickness. The formulation includes both the geometric nonlinearity and inertia effects. The governing equations, derived based on Lagrange’s equations of motion, are solved iteratively through an eigenvalue approach. The formulation is tested against various problems for which the solutions are available in the literature. A detailed analysis is made to assess the influence of fiber angles, lamination schemes, boundary conditions, thickness, and aspect ratios on the nonlinear frequency ratio at large amplitude vibrations of the laminates. A comparative study is also done along with the first-order and simple higher-order theory deduced from the present model by neglecting the thickness stretching effects. The present analysis shows the degree of hardening behavior getting affected noticeably compared to those of the traditional straight fibers, thus exhibiting the occurrence of drop off in frequency ratio and redistribution of mode shapes at certain amplitudes of vibration.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-25T09:54:38Z
      DOI: 10.1142/S021945541850147X
       
  • Time-Variant Seismic Performance of Offshore RC Bridge Columns with
           Uncertainty
    • Authors: Hong-Nan Li, Hu Cheng, Dong-Sheng Wang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      To establish a framework for evaluating the time-variant seismic performance of deteriorated reinforced concrete (RC) structures with uncertainty, offshore RC bridge columns exposed to marine environments are studied in this paper. The uncertainties from the material parameters, corrosion initiation time and earthquake ground motions are taken into account. Due to the different corrosion characteristics in various zones (i.e. the submerged zone, splash and tidal zone, and atmospheric zone) along the column height, corrosion-induced damages in each zone are considered separately, and the geometric mean of the yield displacements of the three zones is used to define the structural capacity (limit state). Meanwhile, the time-variant limit states are determined based on nonlinear static analyses, which reflect the current state of deteriorating RC columns. A total of four cases are studied using the Latin hypercube sampling (LHS) technique based on the probability distributions of the material parameters and corrosion initiation time, including the effects of statistical correlations among the material parameters. The results reveal that the seismic fragility is underestimated by a deterministic numerical model. The uncertainty in the corrosion initiation time influences the seismic fragility less significantly than that in the structural material parameters whether or not anti-corrosion measures are implemented. It is suggested that probabilistic methods should be used for seismic evaluation of deteriorating RC structures to consider the uncertainty involved.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-25T09:54:38Z
      DOI: 10.1142/S0219455418501493
       
  • Dynamics of a Pedestrian’s Walking Motion Based on the Inverted
           Pendulum Model
    • Authors: Lijun Ouyang, TingTing Li, Bin Zhen, Lei Wei
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, the inverted pendulum model is proposed to describe a pedestrian’s walking motion by considering that the pivot point vibrates periodically up and down. The stability, periodic solutions and oscillations of the inverted pendulum are theoretically investigated, the correctness of which is illustrated by numerical simulations. According to frequency spectrum analysis, the inverted pendulum can exhibit periodically or quasi-periodically stable oscillations. However, we demonstrate that the inverted pendulum will maintain the ratio between the lateral and vertical vibration frequencies near [math] as an optimizing selection of stability. The theoretical result agrees with the measurement result for a normal pedestrian such that the lateral step frequency is always half the vertical step frequency, which means that it is feasible and reasonable to describe a pedestrian’s walking motion using the inverted pendulum with the pivot vibrating harmonically in the vertical direction. The inverted pendulum model suggested in this paper could contribute to the study of pedestrian–footbridge interaction, which overcomes the difficulty of directly determining the expression of the lateral force induced by pedestrians.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-22T08:48:26Z
      DOI: 10.1142/S0219455418501456
       
  • Vibration Behavior and Serviceability of Arched Prestressed Concrete Truss
           Due to Human Activity
    • Authors: Jiang Li, Jiepeng Liu, Liang Cao, Y. Frank Chen
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The current trend toward longer spans and lighter floor systems, combined with reduced damping and new activities, have resulted in an increasing complaints on floor vibration from building owners and occupants. Heel-drop, jumping, and walking impacts, which may lead to discomfort problems in daily life, were imposed on a large-span arched prestressed concrete truss (APT) girder system studied. The natural frequencies, peak acceleration, average root-mean-square acceleration (ARMS), maximum transient vibration value (MTVV), and perception factor for the girder were obtained and checked against the existing codes and standards. The purpose of this paper is to provide researchers and engineers with a detailed evaluation on the vibration behavior of the APT girder under different human activities, with a comprehensive review on the relevant criteria and some suggestions. Lastly, the following threshold peak accelerations are suggested: 650[math]mm/s2 for transient heel-drop impact, 1450[math]mm/s2 for transient jumping impact, and 250[math]mm/s2 for steady-state walking. In addition, the threshold values of 90[math]mm/s2 and 50[math]mm/s2 are suggested for MTVV and ARMS, respectively, under steady-state walking.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-22T08:48:25Z
      DOI: 10.1142/S0219455418501468
       
  • Medium- and High-Frequency Vibration Characteristics of a Box-Girder by
           the Waveguide Finite Element Method
    • Authors: Lizhong Song, Xiaozhen Li, Hong Hao, Xun Zhang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      An approach to predicting the vibration responses of a bridge and analyzing the wave propagation characteristics along the bridge is proposed based on the waveguide finite element (WFE) method. For verification, a field vibration test was performed on a 30[math]m-long simply supported box-girder on the fourth line of Guangzhou Metro in China. The numerical results were shown to agree well with the test results, demonstrating the accuracy of the proposed approach. The advantages of the WFE approach are discussed by comparing the WFE with finite element (FE) analyses. The dispersion characteristics and mode shapes of waves propagating in the box-girder are calculated by using the WFE method, from which the dominant wave modes corresponding to the peaks of the medium- and high-frequency train-induced vibrations are identified. A vibration reduction measure is considered. Both the test and numerical results show that the medium- and high-frequency vibrations of the box-girder are predominately in the 1/3 octave center frequency range of 63–100[math]Hz with maximum occurring at the center frequency of 80[math]Hz. The WFE method has higher computational efficiency and requires smaller storage space than the FE counterpart, but provides similar predictions as the latter. In total, there are 14 wave modes propagating in the box-girder below 200[math]Hz. The G1, A1 and D2 wave modes are the dominant wave modes generating vibration velocity peaks on the top, bottom and flange slabs, respectively. Adding a middle web slab to the center of the cross-section is an effective way to mitigate the vibration of the box-girder bridge.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-18T11:09:50Z
      DOI: 10.1142/S0219455418501419
       
  • Thermal Buckling and Postbuckling Analysis of Functionally Graded Concrete
           Slabs with Initial Imperfections
    • Authors: Huanqing Zhang, Zheng Zhang, Helong Wu, Sritawat Kitipornchai, Guozhong Chai, Jie Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper proposes a novel functionally graded (FG) concrete slab and investigates its thermal buckling and postbuckling performance using the finite-element (FE) method. The concrete slab consists of three homogeneous thick layers — a fiber-reinforced concrete layer, a geopolymer concrete layer, and a plain Portland cement (PPC) layer — with a thin FG layer between the thick layers. The mechanical properties of the thin FG layers are exponentially graded across the thickness direction. The effects of initial imperfection, the self-weight of the slab, and the friction between the slab and rigid foundation are considered in the analysis. The FE model is validated against the results reported in the literature. A comprehensive parametric study is conducted to examine the effects of the thickness and volume fraction index of the FG layer, initial imperfection, self-weight, friction, and slab slenderness ratio on the thermal buckling and postbuckling behaviors of the concrete slab. The numerical results demonstrate that the proposed FG slab exhibits remarkably better buckling and postbuckling resistance than a conventional PPC concrete slab and that the influences of both self-weight and friction are important and cannot be neglected.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-18T11:09:48Z
      DOI: 10.1142/S0219455418501420
       
  • Vibration Analysis of Woven Fiber Metal Laminated Plates —
           Experimental and Numerical Studies
    • Authors: E. V. Prasad, S. K. Sahu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The present study deals with numerical and experimental investigations on the vibration behavior of fiber-metal-laminated (FML) plates, a new aircraft material. A finite element (FE)-based formulation is established for the plate using the first-order Reissner–Mindlin theory, including both fibers and metals of different material properties in alternate layers. A four-node isoparametric quadratic element with five degrees of freedom per node is adopted in the analysis. Convergence studies and comparison with previous studies are made to validate the present FE formulation. A set of experiments was conducted to get natural frequencies of vibration for glass FML (GFML) plates using Bruel and Kjaer (B&K) Fast Fourier Transform (FFT) analyzer with PULSE platform. The effects of different parameters such as aspect ratio, side-to-thickness ratio, ply orientation, and boundary conditions on the dynamic behavior of the FMLs are studied. Good agreement is achieved between the numerical and experimental results. Both results indicate that increasing the aspect ratio can increase the natural frequency of the FML plate, while the increase in the side-to-thickness ratio decreases the natural frequency of vibration. The boundary conditions can significantly affect the natural frequency of the FML plates due to the restraint effect at the edges.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-18T11:09:47Z
      DOI: 10.1142/S0219455418501444
       
  • Dynamic Analysis of a Coupled System of High-Speed Maglev Train and Curved
           Viaduct
    • Authors: Z. L. Wang, Y. L. Xu, G. Q. Li, S. W. Chen, X. L. Zhang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This study presents a framework for dynamic analysis of a coupled system of high-speed maglev train and curved viaduct. A series of trajectory coordinates are used to define the motion of maglev vehicles moving over a horizontally curved track, the stiffness and damping matrices of the equations can be thus reduced into those of the straight track. The curved viaduct system is modeled in the global coordinate system using the finite element method, in which the inner and outer rails in the different horizontal planes are duly included. The electromagnet force-air gap model is adopted for the maglev vehicle via its electromagnets and rails on the viaduct, by appropriate transformation of coordinates. By applying the proposed framework to the Shanghai maglev line, curved path-induced dynamic responses and characteristics of the vehicle are explored, which agree well with the measurement ones. The dynamic responses of the curved viaduct are also examined in the vertical, lateral and rotational directions by comparison with the straight viaduct. Moreover, the effect of various curve radii and cant deficiencies on the coupled system are investigated. The results show that for a maglev vehicle moving with an initial equilibrium state, its lateral and rotational response are mainly excited by track roughness. In addition to the track radius, cant deficiencies significantly affect the operational safety of the viaduct.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-18T11:09:46Z
      DOI: 10.1142/S0219455418501432
       
  • A Higher Order Shear Deformation Approach to the Local Buckling Behavior
           of Moderately Thick Composite Laminated Beams
    • Authors: Johannes Herrmann, Torsten Kühn, Tjorven Müllenstedt, Siham Mittelstedt, Christian Mittelstedt
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a novel closed-form analytical approximate solution for the local buckling behavior of composite laminated beams under uniform axial compression. The laminates that constitute the segments of the beam cross-sections (i.e. webs and flanges) are assumed to be moderately thick so that the current analysis approach is based on Reddy’s third-order shear deformation theory' (TSDT). The idealization relies on the discrete plate approach, meaning that the individual segments are separated from the beam cross-section, and the local buckling behavior is analyzed by performing a TSDT-based plate buckling analysis by assuming adequate boundary conditions for webs and flanges. At those edges where the segment under consideration has been separated from the cross-section, elastic restraints are applied to the stiffness values of which depend on the geometric and material properties of the adjacent segments. The analysis approach uses the principle of minimum elastic potential of the considered discrete plate in the buckled state and relies on rather simple shape functions for the buckling modes, thus eventually enabling a closed-form analytical approximate solution that does not necessitate any numerical means of evaluation. Results are generated for a number of I-beam configurations and are compared to results generated in the framework of classical laminated plate theory (CLPT) and first-order shear deformation theory (FSDT). It is shown that the present new approach delivers reliable results without any significant computational effort and thus can be recommended for all engineering analysis tasks where computational time and effort are deciding factors in day-to-day engineering work, such as systematic optimizations or extensive parametric studies.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-07T08:20:17Z
      DOI: 10.1142/S0219455418501390
       
  • Response Control of a High-Rise Television Tower under Seismic Excitations
           by Friction Dampers
    • Authors: Bo Chen, Deng Yang, Yue Zheng, Ke Feng, Yiqin Ouyang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      High-rise television towers are prone to external wind and earthquake-induced oscillations in severe environments. To avoid excessive vibration under strong earthquakes, a large television tower requires certain measures to abate its dynamic responses. Friction dampers are simple and low-cost solutions for realizing the response control of television towers. In this study, response mitigation and performance assessment are conducted on a large-scale television tower with friction dampers under strong earthquakes. A 3D finite element static model of the high-rise television tower is first established, and then a 2D lumped mass dynamic model is developed. The mechanical model for the friction dampers is presented with the axial stiffness considered. The equations of motion of the damper–tower system under seismic excitations are then determined. The control force transformation, displacement increment transformation, and numerical integration of the coupled damper–tower system’s equations of motion are defined on the basis of the two aforementioned models. Finally, the seismic responses of a high-rise television tower system constructed in China are taken as an example to investigate the validity of the proposed control approach using the friction dampers. The results demonstrate that the implementation of friction dampers with optimal parameters in a large truss tower can substantially suppress the structural seismic responses in terms of peak responses and vibrant energy.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-07T08:20:17Z
      DOI: 10.1142/S0219455418501407
       
  • Simulation of Vortex-Induced Vibration of Long-Span Bridges: A Nonlinear
           Normal Mode Approach
    • Authors: Kun Xu, Yaojun Ge, Lin Zhao, Xiuli Du
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Due to the lack of analytic technique for simulating the vortex-induced vibration (VIV) of long-span bridges, a combination of the VIV semi-empirical model with the structural equation of motion is widely employed to calculate the responses of bridge structures. However, the applicability of this method has seldom been investigated before. In this study, the theoretical defects of the conventional combination strategy (i.e. the finite element procedure or the linear normal mode procedure, LNM) are first discussed, a more theoretically reliable approach (the nonlinear norm mode approach, NNM) is then proposed, and the closed-form expression for the NNM of the VIV system is derived. The accuracy of the proposed method is further illustrated by two case studies. This new approach offers a theoretically reliable tool for analyzing the VIV of long-span bridges. It can also be applied to the process of VIV fatigue analysis or control strategy optimization.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-03T10:11:00Z
      DOI: 10.1142/S0219455418501365
       
  • Free Vibration and Elastic Critical Load of Functionally Graded Material
           Thin Cylindrical Shells Under Internal Pressure
    • Authors: Yueyang Han, Xiang Zhu, Tianyun Li, Yunyan Yu, Xiaofang Hu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      An analytical approach for predicting the free vibration and elastic critical load of functionally graded material (FGM) thin cylindrical shells filled with internal pressured fluid is presented in this study. The vibration of the FGM cylindrical shell is described by the Flügge shell theory, where the internal static pressure is considered as the prestress term in the shell equations. The motion of the internal fluid is described by the acoustic wave equation. The natural frequencies of the FGM cylindrical shell under different internal pressures are obtained with the wave propagation method. The relationship between the internal pressure and the natural frequency of the cylindrical shell is analyzed. Then the linear extrapolation method is employed to obtain the elastic critical load of the FGM cylindrical shell from the condition that the increasing pressure has resulted in zero natural frequency. The accuracy of the present method is verified by comparison with the published results. The effects of gradient index, boundary conditions and structural parameters on the elastic critical load of the FGM cylindrical shell are discussed. Compared with the experimental and numerical analyses based on the external pressure, the present method is simple and easy to carry out.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-03T10:10:59Z
      DOI: 10.1142/S0219455418501389
       
  • Further Revelation on Damage Detection by IAS Computed from the
           Contact-Point Response of a Moving Vehicle
    • Authors: Y. B. Yang, Bin Zhang, Yao Qian, Yuntian Wu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The instantaneous amplitude squared (IAS) of the driving component of the contact-point response of a moving test vehicle was proposed for the damage detection of the sustaining bridge. As a supplement to the properties previously presented for the IAS, this paper is aimed at unveiling the key feature of the discontinuity amplification inherent in the IAS through the double guarantee of a “square operation” in the definition and a “second derivative” in computing the contact-point response. The capability of the IAS was demonstrated with regard to the effects of the environmental noise, vehicle damping and bridge damping in the numerical simulation. It is confirmed that the IAS can be reliably used in the damage detection of bridges by a moving test vehicle.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-05-03T10:10:58Z
      DOI: 10.1142/S0219455418501377
       
  • Thermoelastic Vibration of Shear Deformable Functionally Graded Curved
           Beams with Microstructural Defects
    • Authors: Mohammad Amir, Mohammad Talha
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In the present study, the thermoelastic vibration of shear deformable functionally graded material (FGM) curved beams with microstructural defects (porosity) has been analyzed by the finite element method. The formulation is based on the higher-order shear deformation theory. The material properties of FGM beams are allowed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the constituents. Even and uneven distributions of porosities in the beam have been considered with temperature-dependent material properties. Comparison and convergence study has been performed to validate the present formulation. Parametric studies have been done to study the effect of different influencing parameters on the frequency of the FGM curved beam, i.e. porosity, temperature rise, volume fraction index and opening angle. Some new results are presented which can be used as benchmark solutions for future research.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-04-30T03:23:44Z
      DOI: 10.1142/S0219455418501353
       
  • Distributed Strain Damage Identification Technique for Long-Span Bridges
           Under Ambient Excitation
    • Authors: Zhao-Dong Xu, Shu Li, Xin Zeng
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Distributed strain measurement, such as long-gauge fiber bragger grating (FBG) techniques, has developed rapidly in the field of structural health monitoring. However, strategies of corresponding damage identification still need to be enhanced. The damage identification technique based on distributed strain measurement is proposed identifying the structural damage under ambient excitation. Damage indices, like the distributed strain energy difference (DSED) and the relative distributed strain energy (RDSE), are derived from the power spectral density of the frequency response function of distributed strain response and further employed by detecting damages in the structure. A numerical analysis is performed on a long-span cable-stayed bridge with several assumed damage scenarios at various degrees in the girder. Damage localization capability and robustness of the proposed damage indices are discussed. In addition, damage quantification utilizing the proposed indices is conducted. The results indicate that the proposed technique can accurately identify the locations and extent of the damage under ambient vibration excitation.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-04-23T08:53:28Z
      DOI: 10.1142/S021945541850133X
       
  • Edgewise Bending Vibration Analysis of a Rotating Sandwich Beam with
           Magnetorheological Elastomer Core
    • Authors: S. Bornassi, H. M. Navazi, H. Haddadpour
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The vibration of a rotating sandwich beam with magnetorheological elastomer (MRE) as a core between two elastic layers is theoretically analyzed in this paper. This study is focused on the bending vibration along the edgewise direction of a sandwich beam of rectangular cross-section, which, to the best of our knowledge, has not been addressed yet. The classical Euler–Bernoulli beam theory is used to model the dynamic behavior of the elastic layers. In the modeling, the effect of the MRE layer is considered by incorporating its shear strains and the inertia due to shear deformation and bending motion. The governing equations of motion of the rotating sandwich beam are derived by using the Ritz method and the Lagrange’s equations. The effects of the applied magnetic field, core layer thickness, rotational speed, setting angle and hub radius on the natural frequencies and the corresponding loss factors are investigated parametrically. The results show the significant effect of the magnetic field intensity and the MRE layer thickness on the modal characteristics of the MRE sandwich beam.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-04-23T08:53:28Z
      DOI: 10.1142/S0219455418501341
       
  • Ritz-Based Analytical Solutions for Bending, Buckling and Vibration
           Behavior of Laminated Composite Beams
    • Authors: Ngoc-Duong Nguyen, Trung-Kien Nguyen, Thuc P. Vo, Huu-Tai Thai
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, the Ritz-based solutions are developed for the bending, buckling and vibration behaviors of laminated composite beams with arbitrary lay-ups. A quasi-3D theory, which accounts for a higher-order variation of both the axial and transverse displacements, is used to capture the effects of both shear and normal deformations on the behaviors of composite beams. Numerical results for various boundary conditions are presented and compared with existing ones available in the literature. Besides, the effects of fiber angle, span-to-height ratio, material anisotropy and Poisson’s ratio on the displacements, stresses, natural frequencies and buckling loads of the composite beams are investigated.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-04-12T08:13:23Z
      DOI: 10.1142/S0219455418501304
       
  • Static and Dynamic Analyses of Mindlin Plates Resting on Viscoelastic
           Foundation by Using Moving Element Method
    • Authors: Van Hai Luong, Tan Ngoc Than Cao, Junuthula Narasimha Reddy, Kok Keng Ang, Minh Thi Tran, Jian Dai
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Presented herein is a novel computational approach using the moving element method (MEM) for simulating the dynamic response of Mindlin plate resting on a viscoelastic foundation and subjected to moving loads. The governing equations and the element mass, damping and stiffness matrices are formulated in a convected coordinate system in which the origin is attached to the point of the moving applied load. Thus, the method simply treats moving loads as ‘stationary’ at the nodes of the plate to avoid updating the locations of moving loads due to the change of the contact points on the plate. To verify the accuracy of the proposed computational approach, static and free vibration analyses of plates are investigated first. Next, the dynamic response of plate resting on a viscoelastic foundation subjected to a moving load is examined. A parametric study is performed to determine the effects of the load’s velocity, foundation damping and foundation stiffness on the dynamic response of a plate. Finally, the comparisons of the dynamic response of plates resting on viscoelastic foundation and subjected to moving vehicles with three models of load (single-wheel, single-axle and tandem-axle) are discussed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-04-12T08:13:23Z
      DOI: 10.1142/S0219455418501316
       
  • Out-of-Plane Responses of Overspeeding High-Speed Train on Curved Track
    • Authors: Jian Dai, Kok Keng Ang, Van Hai Luong, Minh Thi Tran, Dongqi Jiang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a numerical study on the out-of-plane responses of a high-speed train running on a curved railway track segment using the moving element method. The accuracy and efficiency of the proposed computation model presented herein are compared with available analytical results from the literature and a finite element solver based on a simplified moving load model. Thereafter, a half-railcar moving sprung-mass model and a double-rail track-foundation model are presented to investigate the behavior of a high-speed train traversing a curved track, particularly when the train speed is greater than the design speed of the curved track segment. The results show that the train speed and severity of track irregularity significantly affect the contact forces on the rails. This paper also presents a case of a railcar overturning when the train speed is greater than 2.5 times the design speed of a curved track segment.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-04-12T08:13:22Z
      DOI: 10.1142/S0219455418501328
       
  • Numerical Simulation of Dynamic Stability of Fractional Stochastic Systems
    • Authors: Jian Deng
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The modern theory of stochastic dynamic stability is founded on two main exponents: the largest Lyapunov exponent and moment Lyapunov exponent. Since any fractional viscoelastic system is indeed a system with memory, data normalization during iterations will disregard past values of the response and therefore the use of data normalization seems not appropriate in numerical simulation of such systems. A new numerical simulation method is proposed for determining the [math]th moment Lyapunov exponent, which governs the [math]th moment stability of the fractional stochastic systems. The largest Lyapunov exponent can also be obtained from moment Lyapunov exponents. Examples of the two-dimensional fractional systems under wideband noise and bounded noise excitations are presented to illustrate the simulation method.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-29T09:57:42Z
      DOI: 10.1142/S0219455418501286
       
  • Floating Ice Load Reduction of Offshore Wind Turbines by Two Approaches
    • Authors: Kehua Ye, Chun Li, Fudong Chen, Zifei Xu, Wanfu Zhang, Junwei Zhang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The offshore wind turbines (OWTs) constructed at the northern sea areas under cold climate are frequently subjected to floating ice loads. It is imperative to reduce the damage owing to the floating ice with some appropriate approaches. The purpose of this paper is to ascertain the effectiveness of the tuned mass damper (TMD) and the ice-breaking cone for reducing floating ice loads on OWTs. The National Renewable Energy Laboratory’s (NREL) 5 MW OWT, which is treated as a multibody system with rigid and flexible parts, is adopted as the example model here. The multiple loads taken into consideration in the fully coupled simulation include floating ice and turbulent wind. The aerodynamic load acting on the blades is solved by the blade element momentum method based on a full-field turbulent wind farm generated by the Kaimal spectrum. The Matlock model and the Ralston model are adopted for evaluating the floating ice loads on the cylindrical and conical structures, respectively. The TMD system in the nacelle and the ice-breaking cone on the tower at the mean sea level are the two load reduction approaches of concern in this paper. A weak aeroelastic simulation of the OWT model is conducted. The solution of flexibility effectiveness depends on some accurate mode shapes by the linear modal representation. Finally, Kane’s method is used for predicting the motion of the whole OWT. The relevant results reveal some positive effectiveness of the TMD system and the ice-breaking cone for reducing the floating ice load. The displacement of tower top decreases significantly with the utilization of the two approaches. The TMD system has a better performance for the side-side displacement than the fore-aft displacement. By switching the ice failure mode from crushing to bending, the ice-breaking cone reduces the floating load more effectively than the TMD system. It affects equally significantly the fore-aft and side-side displacements.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-29T09:57:42Z
      DOI: 10.1142/S0219455418501298
       
  • Elastic Rebound of a Blast Door Under Explosion Loadings
    • Authors: Qiushi Yan, Dong Guo
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Rebound effects can be caused for a blast door under explosion loadings of conventional weapons. Such effects reaching a certain extent can lead to severe reversed stresses and even destroy the hinge and lock system before the door leaf. In this study, an analytical model for the elastic rebound of a blast door under explosion loadings was proposed and analyzed. Based on the calculations, the effects of aspect ratio and load duration on the rebound behavior were analyzed. Furthermore, for extension of the analysis from the elastic to plastic range, comparison of the solutions with the analytical ones was made. The results showed that the positive and negative dynamic shear force peaks of the blast door deceased gradually with the aspect ratio, whereas the rebound strength was inversely proportional to the load duration. For blast doors entering into the plastic stage, the rebound behavior was similar to the elastic stage, implying that the design of a blast door can be based on its characteristics in elastic stage.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-29T09:57:42Z
      DOI: 10.1142/S0219455418710116
       
  • Effect of the Casimir Force on Buckling of a Double-Nanowire System with
           Surface Effects
    • Authors: J. Zou, X.-F. Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Structural stability of a double-nanowire system with surface effects subjected to axial compressive forces is analyzed. Taking into account the Casimir force between the two nanowires, two coupled governing equations for buckling of a double-nanowire system are derived. For four typical end supports including simply-supported, clamped, cantilevered, and clamped-pinned double-nanowire systems, the characteristic equations are derived and the critical loads are determined for the out-of-phase in-plane buckling. Numerical results indicate that positive surface elasticity enhances the load-carrying capacity of the nanowires, and the reverse is also true. The Casimir force and residual surface tension always increase the critical loads.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-29T08:17:10Z
      DOI: 10.1142/S0219455418501183
       
  • Experimental Study on Pedestrians’ Perception of Human-Induced
           Vibrations of Footbridges
    • Authors: Rujin Ma, Lu Ke, Dalei Wang, Airong Chen, Zichao Pan
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Owing to the slenderness and lightness of most modern footbridges, vibration serviceability assessment becomes a crucial issue in the design process. As one of the key factors, the vibration comfort criterion has an important influence on the assessment of the final result. However, there is an obvious lack of experimental studies in this field, especially regarding the pedestrians’ perception of the induced vibrations. In this study, an experiment was conducted to investigate the pedestrians’ perception of human-induced vibrations of footbridges. During the experiment, the subjects walked on a pathway that was mounted on top of a shaking table. By imposing sinusoidal excitations with different amplitudes and frequencies, the experiment aimed to determine the influence of the two factors on the walking people’s perception. Based on the data collected, perception scales were proposed for both the vertical and lateral vibrations of the footbridge. The established scales comprise five levels that depend on the acceleration amplitude and the frequency. Finally, a comparison between the proposed scales, existing comfort criteria in the literature and international codes was carried out.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-27T09:04:16Z
      DOI: 10.1142/S021945541850116X
       
  • Probabilistic Damage Detection of Long-Span Bridges Using Measured Modal
           Frequencies and Temperature
    • Authors: Yang Deng, Aiqun Li, Dongming Feng
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper aims to develop a new probabilistic monitoring-based framework for damage detection of long-span bridges, by eliminating the temperature effects from the measured modal frequencies, probabilistic modeling of modal frequencies using kernel density estimate, and detection damage using the control chart. A methodology is presented to address the issue of modal frequencies’ non-normal distribution, which has been neglected in the past studies using the control chart to detect the modal frequencies’ abnormality caused by structural damages. The efficiency of the proposed framework is validated through a case study of long-term monitoring data of a long-span suspension bridge. The results show that after elimination of the temperature effects, the selected modal frequencies are not normally distributed, while the Q statistics transferred from the modal frequencies follow the standard normal distribution. The abnormality of modal frequencies can be detected when the data points of the Q statistics exceed the limits of the control chart. Further, the control chart has sufficient sensitivity and thus can be used to detect minor abnormalities of the prototype bridge’s modal frequencies. It is concluded that the proposed probabilistic monitoring-based framework offers an effective technique for structural health monitoring of long-span bridges.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-26T02:45:07Z
      DOI: 10.1142/S0219455418501262
       
  • Seismic Performance Assessment of RC Frame Structures Subjected to
           Far-Field and Near-Field Ground Motions Considering Strain Rate Effect
    • Authors: Rou-Han Li, Hong-Nan Li, Chao Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper investigates the influence of strain rate effect on the seismic performance of Reinforced concrete (RC) frame structures subjected to far-field and near-field ground motions. An approach for the nonlinear dynamic analysis of RC frame structures considering the strain-rate sensitivity of concrete and reinforcing steel materials is proposed and its effectiveness is validated by the experimental data of RC columns under dynamic loadings. A non-dimensional index is put forward to reveal the regularities of strain rate under different types of ground motions with various intensity levels. The influences of strain rate effect and input ground motion on the seismic performance of the exemplar RC frame are studied by comparing the seismic responses and fragilities of rate-dependent structural models with those of rate-independent ones. Numerical results indicate that the strain rates in structural members increase with the ground motion intensity and the strain rates induced by the near-field pulse-like earthquakes are higher than those by the far-field and near-field non-pulse-like earthquakes. The global response, critical member response, local damage and seismic fragility are all influenced by the strain rate effect, especially under the near-field pulse-like ground motions. Neglecting the influences of strain rate effect, variations in strain rates of different structural members and inputs of pulse-like ground motions may lead to erroneous seismic performance assessments of RC frame structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-26T02:45:07Z
      DOI: 10.1142/S0219455418501274
       
  • Vibrations of a Multi-Span Beam Structure Carrying Many Moving Oscillators
    • Authors: Bingen Yang, Hao Gao, Shibing Liu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A beam structure carrying multiple moving oscillators is a mathematical model for various engineering applications, including rapid transit systems. With many moving oscillators having different speeds and varying inter-distances, the number of oscillators on the structure is time-varying, which inevitably complicates the beam–oscillator interactions. Consequently, the order of a mathematical model for the coupled beam–oscillator system changes with time, with many possibilities. Because of this, it is extremely difficult, if not impossible, for a conventional method to determine the dynamic response of a beam structure carrying many moving oscillators. In the literature, previous investigations have been limited to a beam structure with only one moving oscillator, which may not totally capture the physical behaviors of a structure with many moving oscillators, as seen in certain engineering applications. Developed in this work is a new semi-analytical method that can systematically handle arbitrarily many moving oscillators in both modeling and solution. In the development, an extended solution domain (ESD) is defined and based on the ESD a generalized assumed-mode method is devised. This modeling method completely resolves the issue of changing order in mathematical modeling. Because the proposed method makes use of the exact eigenfunctions of the beam structure (instead of traditional admissible functions), it renders determination of the dynamic response of a coupled beam–oscillator system highly accurate and efficient. The proposed method is demonstrated in several numerical examples. Furthermore, in a benchmark problem, it is shown that for the same accuracy in computation, the elapsed computation time used by the proposed method is just 3.3% of the time required by the finite element method.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-26T02:45:06Z
      DOI: 10.1142/S0219455418501250
       
  • Effect of Porosity on Flexural Vibration of CNT-Reinforced Cylindrical
           Shells in Thermal Environment Using GDQM
    • Authors: Hamed Safarpour, Kianoosh Mohammadi, Majid Ghadiri, Mohammad M. Barooti
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This article investigates the flexural vibration of temperature-dependent and carbon nanotube-reinforced (CNTR) cylindrical shells made of functionally graded (FG) porous materials under various kinds of thermal loadings. The equivalent material properties of the cylindrical shell of concern are estimated using the rule of mixture. Both the cases of uniform distribution (UD) and FG distribution patterns of reinforcements are considered. Thermo-mechanical properties of the cylindrical shell are supposed to vary through the thickness and are estimated using the modified power-law rule, by which the porosities with even and uneven types are approximated. As the porosities occur inside the FG materials during the manufacturing process, it is necessary to consider their impact on the vibration behavior of shells. The present study is featured by consideration of different types of porosities in various CNT reinforcements under various boundary conditions in a single model. The governing equations and boundary conditions are developed using Hamilton’s principle and solved by the generalized differential quadrature method. The accuracy of the present results is verified by comparison with existing ones and those by Navier’s method. The results show that the length to radius ratio and temperature, as well as CNT reinforcement, porosity, thermal loading, and boundary conditions, play an important role on the natural frequency of the cylindrical shell of concern in thermal environment.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-22T06:37:51Z
      DOI: 10.1142/S0219455418501237
       
  • Feasibility Study of Prestress Force Prediction for Concrete Beams Using
           Second-Order Deflections
    • Authors: Marco Bonopera, Kuo-Chun Chang, Chun-Chung Chen, Yu-Chi Sung, Nerio Tullini
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The safety and sustainability of prestressed concrete bridges can be improved with accurate prestress loss prediction. Considerable loss of the prestress force may imply damages hidden in the bridge. In this study, a prestress force identification method was implemented for concrete beams. Based on the Euler–Bernoulli beam theory, the procedure estimates the prestress force by using one or a set of static displacements measured along the member axis. The implementation of this procedure requires information regarding the flexural rigidity of the beam. The deflected shape of a post-tensioned concrete beam, subjected to an additional vertical load, was measured in a short term in several laboratory experiments. The accuracy of the deflection measurements provided favorable prestress force estimates. In particular, the “compression-softening” theory was validated for uncracked post-tensioned concrete beams.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-22T06:37:51Z
      DOI: 10.1142/S0219455418501249
       
  • Dynamic Response of High-Speed Train-Track System Due to Unsupported
           Sleepers
    • Authors: Jian Dai, Kok Keng Ang, Dongqi Jiang, Van Hai Luong, Minh Thi Tran
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper is concerned with a numerical study on the dynamic response of a high-speed rail (HSR) system subjected to unsupported sleepers using the moving element method (MEM). A three-phase computational scheme in conjunction with the MEM is proposed to account for the motion of the unsupported sleepers in relation to the truncated rail segment in the moving coordinate system. The accuracy of the proposed computational scheme is examined by comparison with available analytical results in the literature and against the finite element method using commercial software. A parametric study is conducted using a computational model consisting of a 10-degree of freedom train model and a three-layer ballasted track model to investigate the effect of unsupported sleepers on the dynamic response of the HSR system. Various factors affecting the response of the HSR system, including the speed of the train, the number of unsupported sleepers and the distance between the unsupported sleepers, are examined and discussed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-20T03:21:03Z
      DOI: 10.1142/S0219455418501225
       
  • A Meshfree Higher Order Mass Matrix Formulation for Structural Vibration
           Analysis
    • Authors: Junchao Wu, Dongdong Wang, Zeng Lin
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      An accurate meshfree formulation with higher order mass matrix is proposed for the structural vibration analysis with particular reference to the 1D rod and 2D membrane problems. Unlike the finite element analysis with an explicit mass matrix, the mass matrix of Galerkin meshfree formulation usually does not have an explicit expression due to the rational nature of meshfree shape functions. In order to develop a meshfree higher order mass matrix, a frequency error measure is derived by using the entries of general symmetric stiffness and mass matrices. The frequency error is then expressed as a series expansion of the nodal distance, in which the coefficients of each term are related to the meshfree stiffness and mass matrices. It is theoretically proved that the constant coefficient in the frequency error vanishes identically provided with the linear completeness condition, which does not rely on any specific form of the shape functions. Furthermore, a meshfree higher order mass matrix is developed through a linear combination of the consistent and lumped mass matrices, in which the optimal mass combination coefficient is attained via eliminating the lower order error terms. In particular, the proposed higher order mass matrix with Galerkin meshfree formulation achieves a fourth-order accuracy when the moving least squares or reproducing kernel (RK) meshfree approximation with linear basis function is employed; nonetheless, the conventional meshfree method only gives a second-order accuracy for the frequency computation. In the multidimensional formulation, the optimal mass combination coefficient is a function of the wave propagation angle so that the proposed accurate meshfree method is applicable to the computation of frequencies associated with any wave propagation direction. The superconvergence of the proposed meshfree higher order mass matrix formulation is validated via numerical examples.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-14T07:24:32Z
      DOI: 10.1142/S0219455418501213
       
  • Experiment and Simulation Study on Vibration Control of an Ancient Pagoda
           with Damping Devices
    • Authors: Tao Li, Sheliang Wang, Tao Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In order to choose an effective method for improving the seismic performance of an ancient pagoda called the Small Wild Goose Pagoda, 12 damping devices of varying properties are developed. They are made of shape memory alloy-suspension pendulum damping systems (SMA-SPDSs) based on the restoring force of the SMA wires. By means of the shaking table test, the frequency, equivalent damping and equivalent damping force of the SMA-SPDS are analyzed first to acquire their respective trend of influence. Then, four shock absorption plans (one without SMA-SPDS) are analyzed numerically, and the frequency, displacement and acceleration amplitude, inter-story displacement angle and inter-story shear force calculated are compared with those of the experiment. The results show that the shock absorption rate of Plan 3 is better than all the others, and the simulation results are in agreement with the corresponding experimental results, which also prove that the simulation presented in this paper is feasible, which can be used to verify the rationality and applicability of the device (SMA-SPDS). Therefore, it provides a theoretical means for conducting the strengthening and repairing work of the pagoda concerned.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-14T07:24:31Z
      DOI: 10.1142/S0219455418501201
       
  • Parametric Resonance of Pipes with Soft and Hard Segments Conveying
           Pulsating Fluids
    • Authors: Qian Li, Wei Liu, Zijun Zhang, Zhufeng Yue
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, the parametric resonance of pipes with soft and hard segments induced by pulsating fluids is investigated. The lowest six natural frequencies and mode shapes of the soft–hard combination pipe simply supported at both ends are obtained by the modified Galerkin’s method. The Floquet method is used to numerically determine the parametric resonance regions, including subharmonic resonance regions and combination resonance regions. The parametric resonance results are verified by comparison with published ones, which confirm the validity of the present model establishment and numerical calculation. Compared with a uniform pipe conveying fluid simply supported at both ends, the soft–hard pipe conveying fluid is found to reveal different dynamical behaviors. Decreasing the length of the soft pipe, while increasing the stiffness ratio of the hard pipe compared to the soft one, can effectively improve the stability of the pipe system. The parametric resonance results show that the mean flow velocity and pulsation amplitude of the fluid have a great influence on the width of the parametric resonance regions. It is advisable that the ratio (the soft pipe/the whole pipe) of the length may be designed to be 0.4–0.5 for a flexural rigidity ratio (the hard pipe/the soft pipe) of 2. As the stiffness ratio (the hard pipe/the soft pipe) increases beyond 26, the hard pipe may be regarded as a rigid pipe. The probability of parametric resonance occurrence will be smallest if the soft–hard combination pipe is supported in a clamped–pinned way. For certain application cases, the safety design length of the two pipes with different materials can be determined through numerical calculation.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-14T07:24:29Z
      DOI: 10.1142/S0219455418501195
       
  • Nonlinear Stability Behavior of Cable-Stiffened Single-Layer Latticed
           Shells Under Earthquakes
    • Authors: Pengcheng Li, Lei Wang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A cable-stiffened single-layer latticed shell is an efficient and lightweight structural system in the category of spatial structures. In the past, much emphasis was placed on determining the static stability behavior of this structural system. Relatively little research was attempted on the seismic behavior of cable-stiffened single-layer latticed shells. The article aims to investigate numerically the seismic behavior of this structural system and to compare the behavior of the cable-stiffened single-layer latticed shell with that of the conventional unstiffened shell. The natural vibration characteristics, including the vibration modes and natural frequencies, were examined initially by modal analysis. Subsequently, a time-history analysis was conducted to analyze the nonlinear behavior of the cable-stiffened single-layer latticed shell under the El Centro earthquake. It was demonstrated that the seismic behavior of single-layer latticed shells can be greatly enhanced by the cable-stiffening system. In addition, the effects of pretension in cables, cross-sectional area, and other parameters relating to the seismic behavior of the cable-stiffened latticed shell have also been investigated.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2018-03-02T02:04:51Z
      DOI: 10.1142/S0219455418501171
       
 
 
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