Subjects -> BUILDING AND CONSTRUCTION (Total: 146 journals)
    - BUILDING AND CONSTRUCTION (138 journals)
    - CARPENTRY AND WOODWORK (8 journals)

BUILDING AND CONSTRUCTION (138 journals)                     

Showing 1 - 35 of 35 Journals sorted alphabetically
A+BE : Architecture and the Built Environment     Open Access   (Followers: 34)
Academia : Architecture and Construction     Open Access   (Followers: 3)
ACI Structural Journal     Full-text available via subscription   (Followers: 24)
Advances in Building Education     Open Access   (Followers: 7)
Advances in Building Energy Research     Hybrid Journal   (Followers: 13)
Ambiente Construído     Open Access   (Followers: 1)
Anales de Edificación     Open Access   (Followers: 1)
Asian Journal of Civil Engineering     Hybrid Journal   (Followers: 1)
Australasian Journal of Construction Economics and Building     Open Access   (Followers: 10)
Australasian Journal of Construction Economics and Building - Conference Series     Open Access   (Followers: 1)
Baltic Journal of Real Estate Economics and Construction Management     Open Access   (Followers: 3)
Baurechtliche Blätter : bbl     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 3)
BER : Architects and Quantity Surveyors' Survey     Full-text available via subscription   (Followers: 6)
BER : Building and Construction : Full Survey     Full-text available via subscription   (Followers: 12)
BER : Building Contractors' Survey     Full-text available via subscription   (Followers: 2)
BER : Building Sub-Contractors' Survey     Full-text available via subscription   (Followers: 2)
BER : Capital Goods Industries Survey     Full-text available via subscription  
BER : Survey of Business Conditions in Building and Construction : An Executive Summary     Full-text available via subscription   (Followers: 3)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2)
Building & Management     Open Access   (Followers: 3)
Building Acoustics     Hybrid Journal   (Followers: 4)
Building Research Journal     Open Access   (Followers: 4)
Building Services Engineering Research & Technology     Hybrid Journal   (Followers: 3)
Buildings     Open Access   (Followers: 8)
BUILT : International Journal of Building, Urban, Interior and Landscape Technology     Open Access   (Followers: 1)
Built Environment Inquiry Journal     Open Access  
Built-Environment Sri Lanka     Full-text available via subscription  
Case Studies in Construction Materials     Open Access   (Followers: 10)
Cement and Concrete Composites     Hybrid Journal   (Followers: 22)
Cement and Concrete Research     Hybrid Journal   (Followers: 22)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 7)
Challenge Journal of Concrete Research Letters     Open Access   (Followers: 6)
Change Over Time     Full-text available via subscription   (Followers: 3)
City, Culture and Society     Hybrid Journal   (Followers: 26)
Civil Engineering = Siviele Ingenieurswese     Full-text available via subscription   (Followers: 4)
Clay Technology     Full-text available via subscription  
Concreto y cemento. Investigación y desarrollo     Open Access   (Followers: 1)
Construction Economics and Building     Open Access   (Followers: 4)
Construction Engineering     Open Access   (Followers: 11)
Construction Management and Economics     Hybrid Journal   (Followers: 23)
Construction Research and Innovation     Hybrid Journal   (Followers: 4)
Construction Robotics     Hybrid Journal   (Followers: 3)
Corporate Real Estate Journal     Full-text available via subscription   (Followers: 6)
Dams and Reservoirs     Hybrid Journal   (Followers: 4)
Developments in the Built Environment     Open Access  
Energy and Built Environment     Open Access   (Followers: 1)
Engineering Project Organization Journal     Hybrid Journal   (Followers: 8)
Environment and Urbanization Asia     Hybrid Journal   (Followers: 4)
Frontiers in Built Environment     Open Access   (Followers: 1)
FUTY Journal of the Environment     Full-text available via subscription   (Followers: 1)
Gaceta Técnica     Open Access  
GISAP : Technical Sciences, Construction and Architecture     Open Access  
Glass Structures & Engineering     Hybrid Journal  
Handbook of Adhesives and Sealants     Full-text available via subscription   (Followers: 2)
HBRC Journal     Open Access   (Followers: 2)
Heritage Matters : The Magazine for New Zealanders Restoring, Preserving and Enjoying Our Heritage     Full-text available via subscription   (Followers: 2)
Housing and Society     Hybrid Journal   (Followers: 6)
HVAC&R Research     Hybrid Journal  
Indoor and Built Environment     Hybrid Journal   (Followers: 3)
Informes de la Construcción     Open Access  
Intelligent Buildings International     Hybrid Journal   (Followers: 1)
International Journal of Advanced Structural Engineering     Open Access   (Followers: 25)
International Journal of Air-Conditioning and Refrigeration     Hybrid Journal   (Followers: 17)
International Journal of Architectural Computing     Full-text available via subscription   (Followers: 7)
International Journal of Built Environment and Sustainability     Open Access   (Followers: 7)
International Journal of Concrete Structures and Materials     Open Access   (Followers: 16)
International Journal of Construction Engineering and Management     Open Access   (Followers: 11)
International Journal of Construction Management     Hybrid Journal   (Followers: 4)
International Journal of Masonry Research and Innovation     Hybrid Journal   (Followers: 1)
International Journal of Protective Structures     Hybrid Journal   (Followers: 6)
International Journal of River Basin Management     Hybrid Journal   (Followers: 1)
International Journal of Structural Stability and Dynamics     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Building Technology and Urban Development     Hybrid Journal   (Followers: 13)
International Journal of Sustainable Built Environment     Open Access   (Followers: 7)
International Journal of Sustainable Construction Engineering and Technology     Open Access   (Followers: 9)
International Journal of Sustainable Real Estate and Construction Economics     Hybrid Journal   (Followers: 2)
International Journal of the Built Environment and Asset Management     Hybrid Journal   (Followers: 5)
International Journal of Ventilation     Full-text available via subscription   (Followers: 1)
International Journal Sustainable Construction & Design     Open Access   (Followers: 4)
Journal for Education in the Built Environment     Open Access   (Followers: 3)
Journal of Aging and Environment     Hybrid Journal   (Followers: 6)
Journal of Architecture, Planning and Construction Management     Open Access   (Followers: 11)
Journal of Asian Architecture and Building Engineering     Open Access  
Journal of Building Construction and Planning Research     Open Access   (Followers: 11)
Journal of Building Engineering     Hybrid Journal   (Followers: 4)
Journal of Building Materials and Structures     Open Access   (Followers: 3)
Journal of Building Pathology and Rehabilitation     Hybrid Journal  
Journal of Building Performance Simulation     Hybrid Journal   (Followers: 8)
Journal of Civil Engineering and Construction Technology     Open Access   (Followers: 16)
Journal of Civil Engineering and Management     Open Access   (Followers: 9)
Journal of Computational Acoustics     Hybrid Journal   (Followers: 6)
Journal of Computing in Civil Engineering     Full-text available via subscription   (Followers: 22)
Journal of Construction Engineering     Open Access   (Followers: 9)
Journal of Construction Engineering, Technology & Management     Full-text available via subscription   (Followers: 6)
Journal of Construction Project Management and Innovation     Full-text available via subscription   (Followers: 8)
Journal of Green Building     Full-text available via subscription   (Followers: 12)
Journal of Legal Affairs and Dispute Resolution in Engineering and Construction     Full-text available via subscription   (Followers: 5)
Journal of Sustainable Cement-Based Materials     Hybrid Journal  
Journal of Sustainable Design and Applied Research in Innovative Engineering of the Built Environment     Open Access   (Followers: 2)
Journal of the South African Institution of Civil Engineering     Open Access   (Followers: 2)
Journal of Transport and Land Use     Open Access   (Followers: 26)
Landscape History     Hybrid Journal   (Followers: 14)
Materiales de Construcción     Open Access   (Followers: 2)
Mauerwerk     Hybrid Journal  
Modular and Offsite Construction (MOC) Summit Proceedings |     Open Access   (Followers: 4)
Naval Engineers Journal     Hybrid Journal   (Followers: 2)
Open Construction & Building Technology Journal     Open Access  
Organization, Technology and Management in Construction     Open Access  
PARC Pesquisa em Arquitetura e Construção     Open Access  
Proceedings of the Institution of Civil Engineers - Forensic Engineering     Hybrid Journal  
Proceedings of the Institution of Civil Engineers - Urban Design and Planning     Hybrid Journal   (Followers: 13)
Revista ALCONPAT     Open Access   (Followers: 2)
Revista de la Construcción     Open Access  
Revista de Urbanismo     Open Access   (Followers: 2)
Revista Hábitat Sustenable     Open Access   (Followers: 1)
Revista IBRACON de Estruturas e Materiais     Open Access   (Followers: 1)
Revista Ingenieria de Construcción     Open Access   (Followers: 1)
Revista INVI     Open Access  
RILEM Technical Letters     Open Access  
Room One Thousand     Open Access  
Ruang-Space: Jurnal Lingkungan Binaan (Journal of The Built Environment)     Open Access  
Russian Journal of Construction Science and Technology     Open Access  
Science and Engineering of Composite Materials     Open Access   (Followers: 62)
Science and Technology for the Built Environment     Hybrid Journal   (Followers: 1)
Steel Construction - Design and Research     Hybrid Journal   (Followers: 5)
Stroitel’stvo : Nauka i Obrazovanie     Open Access  
Structural Concrete     Hybrid Journal   (Followers: 10)
Structural Mechanics of Engineering Constructions and Buildings     Open Access   (Followers: 2)
Sustainable Buildings     Open Access   (Followers: 2)
Sustainable Cities and Society     Hybrid Journal   (Followers: 25)
Technology|Architecture + Design     Hybrid Journal  
Terrain.org : A Journal of the Built & Natural Environments     Free   (Followers: 3)
The Historic Environment : Policy & Practice     Hybrid Journal   (Followers: 6)
The IES Journal Part A: Civil & Structural Engineering     Hybrid Journal   (Followers: 6)
Tidsskrift for boligforskning     Open Access  
YBL Journal of Built Environment     Open Access  
Zeitschrift für Miet- und Raumrecht     Hybrid Journal  

           

Similar Journals
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  [119 journals]
  • Prediction of Beyond Design and Residual Performances of Viscoelastic
           Dampers by a Simplified Fractional Derivative Model
    • Authors: Shiang-Jung Wang, Qun-Ying Zhang, Chung-Han Yu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      When subjected to excessive shear deformation, viscoelastic (VE) dampers may inevitably suffer from damages, due to their VE material layers with limited thickness. Under the circumstance, their stiffness and energy dissipation capabilities may deteriorate but not totally vanish. To estimate the seismic performances of viscoelastically damped structures, the beyond design and residual performances of damaged VE dampers are crucial to protect structures from severe failure during the following main shock or aftershocks. On the other hand, for new viscoelastically damped structures under the normal design earthquakes, neglecting the residual performance of damaged VE dampers may result in nonconservative design. Thus, this study aims to provide approaches to analytically characterize the beyond design and residual performances of damaged full-scale VE dampers. Based on the simplified fractional derivative model, the analytical predictions have been compared with the experimental results. The proposed model works well for the design performance of the intact full-scale VE dampers. Particularly, it can also reproduce the beyond design and residual performances of damaged full-scale VE dampers, if due consideration is taken of the effects of excitation frequencies, ambient temperatures, temperature rises, softening, and hardening.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-11T08:00:00Z
      DOI: 10.1142/S0219455421500814
       
  • Frictional Impact-Contacts in Multiple Flexible Links
    • Authors: M. Ahmadizadeh, A. M. Shafei, R. Jafari
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Multiple impacts of 2D (planar) open-loop robotic systems composed of [math] elastic links and revolute joints are studied in this paper. The dynamic equations of motion for such systems are derived by the Gibbs-Appell recursive algorithm, while the regularized method is employed to model the impact-contact mechanism. The Timoshenko beam theory is used to model the transverse vibrations of the links. Also, both the structural damping and air damping are considered to enhance the modeling accuracy. The system joints are assumed to be frictionless and slack-free, but friction force is included for the links colliding with the ground. The [math]-flexible-link system considered goes through a flight phase and an impact phase during its motion. In the impact phase, new equations of motion are derived by including the terms caused by the viscoelastic forces in the system’s differential equations. Owing to the extremely short acting time of the impact force, the related differential equations can be solved only via special treatment, i.e. by detecting the exact moment of impact. To this end, entering or leaving the impact phase is analyzed and controlled with high precision by a special computational algorithm presented in this work. To demonstrate the efficacy and precision of the algorithm developed, computer simulations are conducted to study the dynamic behavior of a 3-link robotic mechanism. To investigate the effect of mode shape on the elastic deformation of links, four different mode shapes are used in the simulations and their results are compared.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-10T08:00:00Z
      DOI: 10.1142/S0219455421500759
       
  • A Dimensionless Number for Response of Blast Loaded Steel Plates
    • Authors: Hongyuan Zhou, Pengli Cong, Xiaojuan Wang, Tianyi Song, Xin Huang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The response of monolithic steel plates subjected to blast was extensively studied, and dozens of dimensionless numbers were proposed to predict the response. While the existing dimensionless numbers are not convenient to use in some scenarios with relatively complicated conditions, the dimensionless number proposed for blast loaded steel plates based on dimensional analysis extends the range of application. Different from other dimensionless numbers, the properties of medium with which the blast load transmits are incorporated to extend the application range to more general scenarios. The responses of the plate subjected to both near-field blast with non-uniform load and far-field blast with uniform load, i.e. both the external and internal blasts (for steel boxes), are reasonably predicted. The physical implication of the proposed dimensionless number is clear in that the media properties, geometrical features, characteristics of material, and loading are incorporated, which are readily available in test. A variety of test data are used to validate the applicability and versatility of the proposed dimensionless number.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-08T08:00:00Z
      DOI: 10.1142/S0219455421500723
       
  • Further Assessment of Three Bathe Algorithms and Implementations for Wave
           Propagation Problems
    • Authors: Jinze Li, Kaiping Yu, Hong Tang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper further analyzes three Bathe algorithms ([math]-Bathe, [math]-Bathe and [math]-Bathe) with their unknown properties revealed. The analysis shows firstly that three Bathe algorithms can cover two common integration schemes, trapezoidal rule and backward Euler formula, and that the second-order [math]-Bathe algorithm is algebraically identical to the [math]-Bathe algorithm. Via formulation of the generalized two-sub-step Newmark algorithm, it is shown that the common Newmark method cannot be considered as a special case of the [math]-Bathe algorithm. For wave propagation problems, optimal Courant–Friedrichs–Lewy (CFL) numbers for reducing dispersion errors are found for the three Bathe algorithms by considering spatial and temporal discretizations simultaneously, while the modified integration rules are used for the element mass and stiffness matrices to reduce the anisotropy in wave propagating directions. The recommended optimal algorithmic parameters are given for the three Bathe algorithms to help users effectively solve various dynamic and wave propagation problems.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-08T08:00:00Z
      DOI: 10.1142/S0219455421500735
       
  • Attenuation and Prediction of the Ground Vibrations Induced by High-Speed
           Trains Running Over Bridge
    • Authors: Yunshi Zhang, Yu Lou, Nan Zhang, Yanmei Cao, Liu Chen
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper aims to study the transfer laws of vibration signals in the free field near a high-speed train line by conducting a field test. The characteristics of ground vibration acceleration were analyzed in the time and frequency domains, and a prediction method in the frequency domain was proposed. The results show: (1) there is a vibration amplification area away from the bottom of the pier under the influence of high-speed trains running over the bridge due to the fluctuation attenuation of the vibration waves; (2) the dominant peak frequency points in the frequency spectrum of the acceleration can be regarded as the resonance frequency induced by periodic loading; and (3) the soil vibration can be effectively predicted by the proposed method with a strong capability to defend the interference of environmental vibrations according to the comparison between the predicted value and the experimental data.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-08T08:00:00Z
      DOI: 10.1142/S0219455421500760
       
  • Analytical Analysis of Interaction Between a Heavy Vehicle and a Simply
           Supported Light Bridge Based on Frequency Modulation
    • Authors: Yao Zhang, Kang Hai Tan
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper analyzes the interaction between a heavy vehicle and a simply supported light bridge based on frequency modulation technique, in which variations of instantaneous frequencies of both bridge and heavy vehicle are considered. The bridge is modeled as a simply supported Euler beam and the heavy vehicle is simplified as a spring-mass system. The variation of instantaneous frequencies of both bridge and vehicle induced by the moving vehicle is usually neglected in classical analysis to decouple the pair of governing equations. However, the coupled vehicle–bridge interaction (VBI) system becomes time-varying and the pair of governing equations cannot be decoupled when the vehicle/bridge mass ratio cannot be neglected. The instantaneous frequencies of both bridge and heavy vehicle including their higher vibration modes are investigated herein. An analytical solution describing the dynamic response of the time-varying VBI system is developed by using the frequency modulation technique. Both Finite Element (FE) method and published experimental data are used for comparison purpose. The predictions of the proposed method match better with those obtained from the FE simulations and experimental measurements than the classical method. Five numerical examples have been adopted to compare the performance of the proposed model and the classical method: the former performs generally well, especially when the vehicle is heavy, or the vehicle frequency is near to the bridge frequency. The classical method is only a special case of the proposed model if either the mass or the stiffness of the vehicle is relatively small compared to the corresponding terms of the bridge. The performance of the proposed method has also been examined in four typical scenarios, where vehicle damping, multi-degree-of-freedom (MDOF) vehicle, road surface roughness, and two-span continuous bridge are involved.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-08T08:00:00Z
      DOI: 10.1142/S021945542150084X
       
  • Forced Vibration Responses of Smart Composite Plates using Trigonometric
           Zigzag Theory
    • Authors: Aniket Chanda, Rosalin Sahoo
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The Trigonometric Zigzag theory is utilized in this research for analytically evaluating the forced vibration responses of smart multilayered laminated composite plates with piezoelectric actuators and sensors. This theory, as the name suggests, incorporates a trigonometric function, namely the secant function for describing the nonlinear behavior of transverse shear stresses through the thickness of the smart composite plates. The kinematics for the in-plane displacement components are obtained by superposing a globally varying nonlinear field through the thickness of the plate structure on a piecewise linearly varying zigzag field with slope discontinuities at the layer interfaces. The model also satisfies the inter-laminar continuity conditions of tractions at the interfaces of the multilayered plate. The equations of motion are derived using Hamilton’s principle, and the separation of the variables technique is extended to assume the solutions for the primary variables in space and time and solved analytically using Navier’s solution technique along with Newmark’s time integration scheme. A detailed analytical investigation of the dynamic behavior of the smart laminated plate coupled with piezoelectric materials like PVDF and piezoelectric fiber-reinforced composite (PFRC) is carried out by considering several forms of the time-dependent electromechanical excitations and also covering different geometrical and material features of the smart plate structure. The responses are found to be in close agreement with the elasticity solutions and some new results are also presented to show the dynamic controlling capacity of the piezoelectric layers.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-04T08:00:00Z
      DOI: 10.1142/S021945542150067X
       
  • Seismic Wave Propagation in Framed Structures by Joint-Based Wave
           Refraction Method
    • Authors: R. Rafiee-Dehkharghani, M. Samadzad, M. Bitaraf, R. Fallahi
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper studies the dynamic behavior of the structural frames subjected to seismic loadings using a joint-based wave refraction method. The beams of the frame are modeled by the Timoshenko beam theory to consider the rotary inertia and shear deformation effects. The whole frame is considered as an assemblage of the waveguides connected with joints and boundary conditions, including discrete spring–dashpots for modeling the foundation supports that are generally treated as discontinuities. The wave refraction matrices at the discontinuities are derived analytically and the final assembled system of equations are solved numerically. The accuracy of the method is validated using an experimental setup and its performance is assessed for a 15-story concrete moment frame subjected to real ground motions. The soil structure interaction effect is also considered in the simulations using discrete spring–dashpot elements. The results show that the wave refraction method can be effectively used as an alternative means for the seismic analysis of the frames. In comparison with numerical methods such as finite element method, the proposed method is computationally efficient, while its accuracy and cost are independent of the loading frequency and the length of waveguides.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-03T08:00:00Z
      DOI: 10.1142/S0219455421500541
       
  • Numerical Studies on the Air–Membrane Interaction of ETFE Cushions
    • Authors: Xiaofeng Wang, Zhuoran Li, Qingshan Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Inflated membranes are popularly used in civil and aerospace engineering. They are flexible and their behaviors are featured by the interaction between the inner air pressure and deformation of the enveloping membrane (air–membrane interaction) which has not yet received attention in the literature. This paper aims at studying the air–membrane interaction and its influence on the static and dynamic properties of an inflated membrane by numerically analyzing a square ETFE (ethylene–tetrafluoroethylene) cushion. To account for the air–membrane interaction, the inner air was regarded as a linear potential fluid in developing the governing equations. The finite element model was derived from the discretized equations and verified through comparison with experimental results and those in the literature. Thereafter, the air–membrane interaction and its variation with influencing factors were investigated in the static and dynamic analysis by comparing results from the verified finite element model with the numerical solutions where the inner air was treated as the traction boundary conditions of the enveloping membrane. Results of this study indicate that (1) air–membrane interaction becomes more prominent with increasing external load and is gradually weakened with a rise in the frequency order; (2) air–membrane interaction makes the top membrane joined with the bottom membrane in the deformation and vibration; and (3) air–membrane interaction is strengthened with an increase in the initial inner pressure or geometric dimensions, but weakened when the membrane thickness or rise–span ratio increases. The present research is helpful to the understanding of the role the inner air plays in the behavior of inflated membranes, and may therefore improve the accuracy in analysis and the rationality in the design.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-03-03T08:00:00Z
      DOI: 10.1142/S0219455421500711
       
  • Buckling and Postbuckling of Plates Made of FG-GPL-Reinforced Porous
           Nanocomposite with Various Shapes and Boundary Conditions
    • Authors: R. Ansari, R. Hassani, R. Gholami, H. Rouhi
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Within the framework of a variational mixed formation and higher-order shear deformation theory (HSDT), a numerical approach is developed in this research to investigate the buckling and post buckling behaviors of variously-shaped plates made of functionally graded graphene platelet-reinforced composites (FG-GPLRCs) taking the effect of porosity into account. By the proposed approach, which can be named as VDQ-FEM, thick and moderately thick plate-type structures with different shapes (e.g. rectangular, skew, or quadrilateral) with arbitrary-shaped cutout (e.g. circular or rectangular) can be studied. Various types for porosity distribution scheme and GPL dispersion pattern including uniform and different functionally graded patterns are considered along the thickness of plate. In the computation of material properties, the closed-cell Gaussian Random field scheme and Halpin–Tsai micromechanical model are utilized. One of the key novelties of proposed approach is developing an efficient way according to the mixed formulation to accommodate the continuity of first-order derivatives on the common boundaries of elements for the used HSDT model. Several numerical examples are given to analyze the influences of porosity coefficient/distribution pattern, GPL weight fraction/dispersion pattern, cutout and boundary conditions on the buckling and postbuckling characteristics of FG-GPLR porous composite plates.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-27T08:00:00Z
      DOI: 10.1142/S0219455421500632
       
  • Two-Stage Automated Operational Modal Analysis Based on Power Spectrum
           Density Transmissibility and Support-Vector Machines
    • Authors: Zhi-Wei Chen, Kui-Ming Liu, Wang-Ji Yan, Jian-Lin Zhang, Wei-Xin Ren
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Power spectrum density transmissibility (PSDT) functions have attracted widespread attention in operational modal analysis (OMA) because of their robustness to excitations. However, the selection of the peaks and stability axes are still subjective and requires further investigation. To this end, this study took advantage of PSDT functions and support-vector machines (SVMs) to propose a two-stage automated modal identification method. In the first stage, the automated identification of peaks is achieved by introducing the peak slope (PS) as a critical index and determining its threshold using the SVM classifier. In the second stage, the automated identification of the stability axis is achieved by introducing the relative difference coefficients (RDCs) of the modal parameters as indicators and determining their thresholds using the SVM classifier. To verify its feasibility and accuracy, the proposed method was applied to an ASCE-benchmark structure in the laboratory and in a high-rise building installed with a structural health monitoring system (SHMS). The results showed that the automated identification method could effectively eliminate spurious modes and accurately identify the closely spaced modes. The proposed method can be automatically applied without manual intervention, and it is robust to noise. It is promising for application to the real-time condition evaluation of civil structures installed with SHMSs.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-26T08:00:00Z
      DOI: 10.1142/S0219455421500681
       
  • Dynamic Stiffness Formulation for Out-of-Plane Natural Vibration of
           Elastically Supported Functionally Graded Plates
    • Authors: Md. Imran Ali, Mohammad Sikandar Azam
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, the natural vibration characteristics of elastically supported functionally graded material plate are investigated using the dynamic stiffness method (DSM). Power-law functionally graded (P-FG) plate, the material properties of which vary smoothly along the thickness direction following the power-law function, that has been used for the analysis. Classical plate theory and Hamilton’s principle are used for deriving the governing differential equation of motion and associated edge conditions for P-FG plate supported by elastic foundation. During the formulation of dynamic stiffness (DS) matrix, the concepts of rotary inertia and neutral surface are implemented. Wittrick–Williams (W-W) algorithm is used as a solving technique for the DS matrix to compute eigenvalues. The results thus obtained by DSM for the isotropic, P-FG plate, and the P-FG plate with elastic foundation compare well with published results that are based on different analytical and numerical methods. The comparisons indicate that this approach is very accurate. Furthermore, results are provided for elastically supported P-FG plate under four different considerations in order to see the differences in frequencies with the inclusion or exclusion of neutral surface and/or rotary inertia. It is noticed that the inclusion of rotary inertia and neutral surface influences the eigenvalues of P-FG plate, and that cannot be discounted. The study also examines the influence of plate geometry, material gradient index, edge conditions, and elastic foundation modulus on the natural frequency of P-FG plate.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-25T08:00:00Z
      DOI: 10.1142/S0219455421500620
       
  • Nonlinear Vibration Analysis of Viscoelastic Smart Sandwich Plates Through
           the use of Fractional Derivative Zener Model
    • Authors: Hamid Reza Talebi Amanieh, Seyed Alireza Seyed Roknizadeh, Arash Reza
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, the nonlinear vibrational behavior of a sandwich plate with embedded viscoelastic material is studied through the use of constitutive equations with fractional derivatives. The studied sandwich structure is consisted of a viscoelastic core that is located between the faces of functionally graded magneto-electro-elastic (FG-MEE). In order to determine the frequency-dependent feature of the viscoelastic layer, four-parameter fractional derivative model is utilized. The material properties of FG-MEE face sheets have been distributed considering the power law scheme along the thickness. In addition, for derivation of the governing equations on the sandwich plate, first-order shear deformation plate theory along with von Karman-type of kinematic nonlinearity are implemented. The derived partial differential equations (PDEs) have been transformed to the ordinary differential equations (ODEs) through the Galerkin method. After that, the nonlinear vibration equations for the sandwich plate have been solved by multiple time scale perturbation technique. Moreover, for evaluating the effect of different parameters such as electric and magnetic fields, fractional order, the ratio of the core-to-face thickness and the power low index on the nonlinear vibration characteristics of sandwich plates with FG-MEE face sheets, the parametric analysis has been performed. The obtained results revealed the enhanced nonlinear natural frequency through an increment in the fractional order. Furthermore, the prominent influence of fractional order on the nonlinear frequency of sandwich plate was declared at the negative electric potential and positive magnetic potential.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-24T08:00:00Z
      DOI: 10.1142/S0219455421500619
       
  • Analysis of the Bi-Stable Hybrid Laminate under Thermal Load
    • Authors: M. Fazli, M. H. Sadr, H. Ghashochi-Bargh
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Adaptive structures have the ability to modify their shapes in different operational conditions. Multi-stable structures are one of the methods of making adaptive structures. In the bi-stable square laminates, due to geometric symmetry and equality of strain energy between stable states, it is possible to continue actuating between stable states, specially when using dynamic or thermal load. The bi-stability of the hybrid square laminated structure with the stacking sequence of [0/90/Al] is asymmetric. This leads to inequality of strain energy in stable states and therefore, development of an effective method to control and avoid automatic actuating. In this paper, the deformation and strain energy of the bi-stable hybrid square laminated structure is investigated. To show the effect of elastic boundary condition, a similar section with the stacking sequence of [0/0/Al] is connected to the mentioned hybrid laminate. The effects of the temperature, the presence of an aluminum layer and its thickness on the potential multiple shapes are also studied. To check the accuracy, the bi-stability behavior is investigated using finite element analysis and the results are compared with the experimental data.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-24T08:00:00Z
      DOI: 10.1142/S0219455421500693
       
  • Simulation of the Dynamic Behavior of a Centenary Metallic Bridge under
           Metro Traffic Actions Based on Advanced Interaction Models
    • Authors: D. Ribeiro, B. Costa, L. Cruz, M. Oliveira, V. Alves, P. Montenegro, R. Calçada
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The present work focuses on the evaluation of the dynamic behavior of a centenary steel arch bridge, located in Portugal, under light railway traffic loads. This works aims to assess the dynamic behavior of the bridge subjected to an alternative type of railway vehicle, more specifically, a typical underground vehicle that is currently in service in the Lisbon Metro. The dynamic response of the system has been evaluated using two distinct methodologies, namely a moving loads model and a vehicle–bridge interaction model. To achieve this goal, finite element (FE) models from both the bridge and the vehicle have been developed and a comprehensive study has been carried to evaluate the influence of distinct factors in the dynamic response of the bridge–train system, namely the methodology used to assess the dynamic response, the location of the response reference point in the deck, the train speed and the vehicle configuration (single or double vehicle). Moreover, both the traffic safety, passenger comfort and pedestrian comfort have also been evaluated using normative criteria based on acceleration responses. The results shown that the normative limits related to traffic safety and passenger comfort were never exceeded in any condition analyzed in the study. However, the pedestrian comfort was jeopardized when the train speed exceeded 20[math]km/h.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-20T08:00:00Z
      DOI: 10.1142/S0219455421500577
       
  • Evaluation of Kriging-NARX Modeling for Uncertainty Quantification of
           Nonlinear SDOF Systems with Degradation
    • Authors: Xiaoshu Gao, Hetao Hou, Liang Huang, Guangquan Yu, Cheng Chen
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Structural assessment for collapse is commonly approached by observing the failure or collapse of systems fully incorporating degradation. Challenges however exist in the performance indicator or damage measure due to compound impacts of uncertainties of external (seismic excitation) and internal (structural properties) characteristics with degradation behavior. To account for the impacts of uncertainties, the state-of-the-art kriging nonlinear autoregressive with exogenous (NARX) model is explored in this study to replicate the response of nonlinear single-degree-of-freedom systems. The generalized hysteretic Bouc-Wen model with internal uncertainties is selected to emulate the stiffness and strength degradation. A probabilistic stochastic ground motion model is introduced to represent the external uncertainties. The global terms of NARX model are selected by least-angle regression algorithm and the kriging model is utilized to surrogate uncertain parameters into corresponding NARX model coefficients. The predictions of kriging NARX models are further compared with that of the polynomial chaos nonlinear autoregressive with exogenous input form model as well as Monte Carlo simulation. The comparisons show that kriging NARX model presents an effective and efficient meta-model technique for uncertainty quantification of systems with degradation.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-20T08:00:00Z
      DOI: 10.1142/S0219455421500607
       
  • Analysis of Structural Vibrations of Vertical Axis Wind Turbine Blades via
           Hamilton’s Principle — Part 3: Pitch Angle and Equilibrium State
    • Authors: Jianyou Huang, Chia-Ou Chang, Chien-Cheng Chang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Pitch angle is one of the most important parameters of wind turbine blade. This study is aimed to investigate the effect of the pitch angle on the deformation of a VAWT. Lagrangian mechanics and Euler’s beam theory are used to derive the motion equations of linear structural vibration for straight blade vertical axis wind turbine blade with the pitch angle [math]. The complete equations of motion take account of the 4-DOF deformation of flexural–flexural–torsion–extension as well as the material damping. Vibration analysis of generalized displacement about the equilibrium state (GDAES) is carried out with respect to the displacement of the equilibrium state (DOES), which is separated from the motion of vibration. After simplifying the equilibrium equation of 4-DOF into 1-DOF system, the exact solution of displacement [math] of the equilibrium state is derived. The correction [math] of [math] due to the pitch angle and the characteristics of [math] with constant linear speed are analyzed. Furthermore, we investigate the coupling effect of lateral bending and axial extension of the blade on [math] is analyzed. Finally, the exact solution of [math] is verified by the central difference method.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-20T08:00:00Z
      DOI: 10.1142/S021945542150070X
       
  • Optimal Design of Dampers for Multi-Mode Cable Vibration Control Based on
           Genetic Algorithm
    • Authors: Fangdian Di, Lin Chen, Limin Sun
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Cables in cable-stayed bridges are subjected to the problem of multi-mode vibrations. Particularly, the first ten modes of long cables can have a frequency less than 3[math]Hz and hence are vulnerable to wind-rain induced vibrations. In practice, mechanical dampers are widely used to mitigate such cable vibrations and thus they have to be designed to provide sufficient damping for all the concerned vibration modes. Meanwhile, the behaviors of practical dampers are complicated and better to be described by mechanical models with many parameters. Furthermore, additional mechanical components such as inerters and negative stiffness devices have been proposed to enhance the damper performance on cables. Therefore, it is increasingly difficult to optimize the damper parameters for suppressing multi-mode cable vibrations. To address this issue, this study proposes a novel damper design method based on the genetic algorithm (GA). The procedure of the method is first introduced where the damper performance optimization is formulated as a single-objective multi-parameter optimization problem. The effectiveness of the method is then verified by considering a viscous damper on a stay cable. Subsequently, the method is applied to optimize three typical dampers for cable vibration control, i.e. the positive stiffness damper, the negative stiffness damper, and the viscous inertial mass damper. The results show that the GA-based method is effective and efficient for cable damper design to achieve best multi-mode control effect and it is particularly useful for dampers with more parameters.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-19T08:00:00Z
      DOI: 10.1142/S0219455421500589
       
  • On Stability of SDOF Systems with Asymmetric Bi-Linear Hysteresis
           Subjected to Seismic Excitations
    • Authors: Patricio Quintana Gallo, Rodrigo Meneses
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This technical note presents a numerical study on the stability of single degree of freedom (SDOF) systems with asymmetric bi-linear hysteretic restoring force, subjected to earthquake excitations. The aim is to report: (a) the existence of an unstable behavior in the response of such systems, under a specific ground motion, given small modifications of the yielding conditions of the hysteresis model, and (b) the introduction of a novel three-dimensional graphic visualization of the problem. The modifications of the yielding conditions were introduced via the symmetry-breaking produced by very small variations of the static equilibrium position of the system, equivalent to having an initial position and restoring force different from zero and symmetric yielding. The concise study comprises of nonlinear dynamic analyses of three system cases, one of them with symmetric (reference) and two with asymmetric yielding conditions. The results show that the system presented a stable response and severe ratcheting toward the weakest yielding direction for the symmetric and asymmetric cases, respectively. Differences as large as [math]% between the asymmetric and reference cases were obtained for the residual displacement of the systems, due to variations as small as [math]% in the static-equilibrium position, and consequent [math]% variations of the positive/negative yielding displacements and forces. In turn, negligible variations of the velocity between the three cases were predicted. To conclude, the paper introduces novel three-dimensional representations of the solution-curve and of the hysteresis cycles of the systems, deepening the discussion on the identified bifurcation. The 3D hysteresis curve, in particular, can be of much use for seismic engineering and mechanical studies, either numerical or experimental, as it allows visualizing the sequence of events in the hysteresis plots in a much clearer fashion compared to the traditional two-dimensional counterparts.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-19T08:00:00Z
      DOI: 10.1142/S0219455421710024
       
  • Nonlinear Traveling-Wave Vibration of a Ring-Stringer Stiffened
           Cylindrical Shell
    • Authors: Lun Liu, Shupeng Sun, Jiajie Han
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The nonlinear traveling-wave vibration of a ring-stringer stiffened cylindrical shell is analyzed. Using Donnell’s nonlinear shell theory and Lagrange equations, the nonlinear dynamic model of the ring-stringer stiffened cylindrical shell is derived. Galerkin’s method based on multi-mode instead of single-mode approximation is used to discretize the shell’s displacements. Two types of orthogonal circumferential modes with same frequency are used and the interaction between them is considered in the analysis of the shell’s nonlinear traveling-wave vibration. The harmonic balance (HB) method, along with the pseudo-arc length continuation algorithm, is adopted to solve the forced vibration responses of the shell. The stability of the solution is determined by the Floquet theory. Through comparison with the results available in the literature, the correctness of the present nonlinear dynamic model and its solution process are validated first. Next, the mode selection rules are determined through a convergence study. Finally, the nonlinear traveling-wave vibration of the ring-stringer stiffened cylindrical shell is studied. Also, the paper investigates, in detail, the effects of stiffener parameters on the nonlinear dynamic characteristics of the stiffened shell.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-16T08:00:00Z
      DOI: 10.1142/S0219455421500590
       
  • A Computational Study on Buckling Behavior of Cold-Formed Steel Built-Up
           Columns Using Compound Spline Finite Strip Method
    • Authors: Akshay Mangal Mahar, S. Arul Jayachandran
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a computational methodology to compute the critical buckling stress of built-up cold-formed steel columns joined with discrete fasteners. The fasteners are modeled as three-dimensional beam elements, and their effect is integrated into the spline finite strip framework, evolving the compound strip methodology. Although this technique has been presented in the literature, this paper presents yet another robust framework for the buckling load evaluation of compound cold-formed steel columns with arbitrarily located fasteners. The proposed framework is applied to study the effect of fasteners on the formation of local, distortional, and global buckling modes of built-up section and a comparison is drawn with the buckling behavior of a single section. In this study, the proposed formulations are also used to get insights into the stability behavior of single-span and multi-span compound cold-formed steel columns in the presence of (i) fasteners with varied spacings with respect to span and (ii) the presence of the additional restraining system such as wall panels. For different buckling modes, a significant increment in buckling stress for a built-up section from a single section is observed when the fastener spacing is kept less than the critical buckling half-wavelength of the respective buckling modes. The study on the effect of wall panels shows that in comparison to unsheathed wall studs, the sheathed wall studs that produce additional constraints lead to the elimination of the global buckling deformations. The proposed formulations are simple, yet rigorous and have been validated using finite element-based numerical results.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-16T08:00:00Z
      DOI: 10.1142/S0219455421500644
       
  • Vibration Characteristics of Unsaturated Runways Under Moving Aircraft
           Loads
    • Authors: Chuxuan Tang, Zheng Lu, Hailin Yao, Shuan Guo, Yukun Han
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The dynamic vibrations of airport runways induced by moving aircraft loads are semi-analytically studied in this paper. The airport runway consists of an infinite Kirchhoff plate, an elastic base course, and an unsaturated poroelastic half-space. The aircraft loads are modeled according to the mechanical properties of the main landing gear of the A380 civil airliner. The governing equations of the whole system are solved in the wavenumber domain using the double Fourier transform. Then the results in the spatial domain are obtained by applying the inverse double Fourier transform. Various parameters including the observation location, soil saturation, load speed, load frequency, and pavement rigidity on the vibration characters of the whole system are investigated. It is found that all these effects are crucial, and the increase of soil saturation leads to a larger maximum vertical displacement and lower critical speed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-16T08:00:00Z
      DOI: 10.1142/S0219455421500656
       
  • A Computationally Efficient Method for Optimum Tuning of Single-Sided
           Pounding Tuned Mass Dampers for Structural Vibration Control
    • Authors: Yildirim Serhat Erdogan, Mehmet Ada
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Pounding tuned mass dampers (PTMD), which relies on impact to dissipate vibration energy, have shown remarkable performance in suppressing structural vibrations with its modest design. However, the optimum design of PTMDs is computationally expensive due to non-smooth contact-impact behavior. This study provides a computationally efficient approach to determine the optimal parameters of single-sided PTMDs used in vibration control of structural systems. An optimization strategy is used to minimize the maximum response of the controlled structure. As is well-known, the calculation of the dynamic response of a structure could be cumbersome when conventional time-stepping techniques are used in each iteration of the optimization routine. Hence, an exact analytical solution of the steady-state vibration is used to calculate the response for different excitation frequencies, which substantially decreases the computational burden. The adopted method is computationally very inexpensive with respect to the conventional time-stepping techniques used to solve the nonlinear equations of motion to obtain response quantities. The exact solution only requires the solution of the system of five nonlinear equations in order to evaluate the steady-state response per each excitation frequency of harmonic force. A four-storey shear building is used to evaluate the optimally-tuned PTMD by the proposed procedure. In addition, simplified design equations for the coefficient of restitution and frequency ratio are provided using curve and surface fitting for preliminary design. It was shown that the effect of damping ratio of the primary structure on the optimal coefficient of restitution value is not considerable, while it has significant influence on the optimal frequency ratio. It was also realized that the objective function used in optimum parameter design has only one local optimum, which is suitable for the application of gradient-based optimization methods.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-10T08:00:00Z
      DOI: 10.1142/S0219455421500668
       
  • Optimal Placement of Sensors for Controlling Smart Base Isolation Systems
    • Authors: Mohtasham Mohebbi, Hamed Dadkhah
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Smart base isolation composed of a low-damping base isolation and a supplemental magneto-rheological (MR) damper is one of the most effective semi-active control systems to protect the structures against earthquake. In this study, optimal placement of sensors is determined by using a mixed-integer genetic algorithm for best possible performance. The results show significant effect of sensor configuration on the control system performance, revealing that the sensor configuration should be taken as an important factor in design process of smart base isolation. Besides, although optimal determination of sensor placement improves the control system performance, a high number of sensors is needed to measure structure responses. A method using the least number of sensors is proposed in order to reduce the control cost. The results show the effectiveness of this method in achieving near-optimal response and reducing the control cost.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-05T08:00:00Z
      DOI: 10.1142/S0219455421500553
       
  • A Non-Iterative Integration Scheme Enriching the Solution to the Coupled
           Maglev Vehicle–Bridge System
    • Authors: Wei Liu, Wenhua Guo
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A non-iterative integration scheme is presented in this study to enrich the solutions to the coupled equations of the maglev vehicle–bridge system. The proposed integration scheme is composed of two integration methods aiming at providing the solutions to equation of motion and state-space equation. First, the equation of motion of the simply supported girder bridge is transformed by the modal superposition method. Then the state-space equation is used to describe the motions of both the vehicle and the suspension control system, with the associated matrices assembled using the fully computerized approach. By adopting this integration scheme, only pure vector calculations arise in the solution process, regardless of the existence of time-dependent displacement and velocity on the right-hand sides of the two coupled equations. The proposed integration method is of the second-order accuracy with and without damping. Being equipped with adequate numerical dissipation and dispersion, the method also possesses the characteristic of little computing errors, as can be achieved through the use of different pairs of parameters. Finally, numerical simulations have been conducted to assess the influence of different feedback gains, three types of bridges with different lengths, and guideway irregularity on the maglev vehicle–bridge system.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-03T08:00:00Z
      DOI: 10.1142/S0219455421500528
       
  • Geometrically Nonlinear Electromechanical Instability of FG Nanobeams by
           Nonlocal Strain Gradient Theory
    • Authors: S. M. J. Hosseini, J. Torabi, R. Ansari, A. Zabihi
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper is concerned with studying the size-dependent nonlinear dynamic pull-in instability and vibration of functionally graded Euler–Bernoulli nanobeams (FG-EBNs) with the von Kármán hypothesis based on the nonlocal strain gradient theory (NLSGT). To this end, the partial differential equation (PDE) is developed by Hamilton’s principle considering the intermolecular, fringing field and electrostatic nonlinear forces. Then, the Galerkin method (GM) is utilized to acquire the ordinary differential equation (ODE) and the results are obtained with the help of an analytical approach called the homotopy analysis method (HAM). To verify the outcome of this study, the nonlinear and linear frequencies obtained are compared with those of the literature. Consequently, the pull-in voltage of the FG nanobeam is obtained and the variations of nonlinear and linear frequencies are discussed in detail. Also, the effects of initial amplitude, electrostatic force, length scale, nonlocal parameter, material gradient index and boundary condition (BC) on the electromechanical behavior of FG-EBNs are analyzed with the results commented.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-01T08:00:00Z
      DOI: 10.1142/S0219455421500516
       
  • Indirect Damage Identification in Bridges Based on Dynamic Tyre Pressure
           Monitoring
    • Authors: G. Sai Kumar, C. G. Krishnanunni, B. N. Rao
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper deals with an indirect health monitoring strategy for bridges using an instrumented vehicle. Thermodynamic principles are used to relate the change in Vehicle–Bridge-Interaction (VBI) forces to the change in dynamic tyre pressure. The damage identification process involves two stages. In the first stage, the unknown tyre model parameters are estimated using Bayesian inference based on the calibration data. The approach uses a Stein variational gradient descent implementation of the Bayes rule to quantify the uncertainty in the estimated tyre parameters. In the second stage, the calibrated tyre model is used to reconstruct the change in VBI force from measured tyre pressure data considering a damaged bridge. It is observed that damage present in the bridge produces notable changes in VBI force. Contour plots based on VBI force and natural frequency are developed for damage detection. The reconstructed VBI force change is used to quantify damage using the contour plots. Further, the least square estimation approach is adopted for damage identification by defining appropriate objective functions and imposing constraints on the damage indicators. The damage is estimated by minimizing the objective function using Cuckoo search algorithm. Numerical experiments reveal that the developed method could be used for accurate damage identification in the presence of measurement noise, uncertainty in estimated tyre parameters, and the uncertainty in bridge model parameters.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-02-01T08:00:00Z
      DOI: 10.1142/S0219455421500565
       
  • Optimal Time-Delay Control for Multi-Degree-of-Freedom Nonlinear Systems
           Excited by Harmonic and Wide-Band Noises
    • Authors: Rongchun Hu, Qiangfeng Lü
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, an optimal time-delay control strategy is designed for multi-degree-of-freedom (multi-DOF) strongly nonlinear systems excited by harmonic and wide-band noises. First, by using the generalized harmonic functions, a stochastic averaging method (SAM) is employed for the time-delay controlled strongly nonlinear system under combined harmonic and wide-band noise excitations, by which a set of partially averaged Itô equations are obtained. Then, by solving the dynamical programming equation associated with the partially averaged Itô equations, the optimal control law can be obtained. Finally, by solving the Fokker–Planck–Kolmogorov (FPK) equation, the responses of the optimally time-delay controlled system are predicted. The analytical results are compared with the Monte Carlo simulation to verify the effectiveness and efficiency of the proposed control strategy.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-27T08:00:00Z
      DOI: 10.1142/S021945542150053X
       
  • Simultaneous Online Damage Detection and Vibration Control of Structures
           Using Synchronization and Semi-Active Control
    • Authors: Mahdi Moradmand, Fereidoun Amini, Pedram Ghaderi
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, a smart structure is developed by integrating a semi-active control strategy with an online synchronization-based damage detection method. In this algorithm, the structural damages are identified in real-time with the synchronization-based method using displacement and velocity measurements of the structure. Then, a fuzzy logic controller is applied for determination of the control forces according to the occurrence of damages. A five-story linear shear building equipped with magneto-rheological (MR) dampers is studied numerically to verify the performance and efficiency of the proposed integrated method for both damage detection and vibration suppression. One damage scenario and four earthquake records are used for such purpose. Results demonstrate that the proposed algorithm has the capability of identifying structural damages satisfactorily while exerting suitable control forces to compensate for the damages occurrence and mitigating the dynamic responses of the structure. Furthermore, it is shown that in comparison with the long-established method of only vibration control, the total energy consumption is significantly reduced, an issue of concern in optimal control of structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-20T08:00:00Z
      DOI: 10.1142/S0219455421500383
       
  • Time-Varying Parameter Identification of Bridges Subject to Moving
           Vehicles Using Ridge Extraction Based on Empirical Wavelet Transform
    • Authors: Jiantao Li, Jian Guo, Xinqun Zhu
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      For a vehicle moving over a bridge, the vehicle-bridge interaction (VBI) embraces the time-varying modal parameters of the system. The identification of non-stationary characteristics of bridge responses due to moving vehicle load is important and remains a challenging task. A new method based on the improved empirical wavelet transform (EWT) along with ridge detection of signals in time-frequency representation (TFR) is proposed to estimate the instantaneous frequencies (IFs) of the bridge. Numerical studies are conducted using a VBI model to investigate the time-varying characteristics of the system. The effects of the measurement noise, road surface roughness and structural damage on the bridge IFs are investigated. Finally, the dynamic responses of an in-situ cable-stayed bridge subjected to a passing vehicle are analyzed to further explore the time varying characteristics of the VBI system. Numerical and experimental studies demonstrate the feasibility and effectiveness of the proposed method on the IF estimation. The identified IFs reveal important time-varying characteristics of the bridge dynamics that is significant to evaluating the actual performance of operational bridges in operation and may be used for structural health assessment.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-18T08:00:00Z
      DOI: 10.1142/S0219455421500462
       
  • Generative Adversarial Networks-Based Stochastic Approach to the Modeling
           of Individual Jumping Loads
    • Authors: Shuqian Duan, Jiecheng Xiong, Hui Qian
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Features of jumping loads are essentially high-dimensional random variables but have been simplistically modeled owing to the lack of proper mathematical tools. Generative adversarial networks (GANs) in conjunction with deep learning technology are adopted herein for modeling the jumping loads. Conditional GANs (CGANs) combined with Wasserstein GANs (WGANs) with gradient penalty (WGANs-GP) are adopted in the impulse modeling, where a multi-layer perceptron and a convolutional neural network are employed for the discriminator and generator, respectively. As for the impulse amplitude sequence and interval sequence modeling, similar CGANs combined with WGANs-GP are adopted, where recurrent neural networks are employed for both the generator and discriminator. A large amount of measured individual jumping loads are utilized in training GANs to ensure the generated samples can simulate the real ones well. After training, the individual jumping loads are simulated by connecting the generated impulse samples, based on the generated impulse amplitude sequence samples and interval sequence samples. The simulated jumping loads can be used to assess the vibration performance of assembly structures, such as grandstands, concert halls, and gym floors. Moreover, the established GANs can be extended to the modeling of other stochastic dynamic excitations.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-18T08:00:00Z
      DOI: 10.1142/S0219455421500474
       
  • Experimental Study of the Effect of Proximity between Adjacent Buildings
           on their Dynamic Response
    • Authors: Gonzalo Barrios, Tam Larkin, Nawawi Chouw
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Most of the experimental works on adjacent structures consider a short distance between them to analyze the interaction. Additionally, the majority of these studies focus on changes in the dynamic response of the buildings (e.g. acceleration, lateral displacement, or rocking) assuming that the fundamental frequency and the damping of the structures remain the same as those for the stand-alone case. This work intends to reveal the effect of distance on the interaction between adjacent structures and the effect of neighboring buildings on the dynamic properties of a structure. This was achieved by studying the dynamic response of single degree-of-freedom (SDOF) structures in a laminar box filled with sand sitting on a shake table. This study initially addressed the attenuation of the acceleration through the soil with the distance considering the structures at different distances. The second part of the study considers multiple configurations of adjacent structures to estimate the influence of the number of neighbors on the fundamental frequency and damping ratio of a subject building. An increasing fundamental frequency with an increasing number of participating structures was observed. An equation to estimate the influence of the number of neighboring buildings on the fundamental frequency of the subject structure is proposed. For the damping ratio, a considerable influence of the soil was observed. The lowest damping was obtained for an intermediate number of structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-18T08:00:00Z
      DOI: 10.1142/S0219455421500486
       
  • Nonlinear Behaviors of Spinning Pipes Conveying Fluid with Pulsation
    • Authors: Morteza Khoshroo, Mojtaba Eftekhari
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Bifurcation analysis is conducted to investigate the dynamics of a spinning pipe conveying fluid with pulsation. The partial differential equations of the system are obtained by considering the nonlinearity in curvature and inertia. They are then discretized to the ordinary differential equations by means of the Galerkin expansion so that the primary and combination resonance conditions are imposed to the system. Moreover, the multiple scales method is utilized to solve the resultant equations, and the stability of the equilibrium points of the system is determined through the continuation method. The equilibrium solutions are also examined by the numerical integration, by which the existence of double jump, saddle node and Hopf bifurcations are demonstrated for different values of the fluid velocity.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-18T08:00:00Z
      DOI: 10.1142/S0219455421500504
       
  • Vibration-based Monitoring for Transverse Cooperative Working Performance
           of Assembled Concrete Multi-Girder Bridge: System Design, Implementation
           and Preliminary Application
    • Authors: Zhaoyuan Xu, Danhui Dan, Lu Deng
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The hinge joints of the assembled concrete multi-girder bridge (ACMGB) are the main components of transverse transmission of loads and the decline of their transmission capacity would lead to the degradation of the transverse cooperative working performance (TCWP) of the multi-beam system. As the key working performance of this kind of bridges, its severe degradation would result in the single-girder-bearing phenomenon inducing bridge collapse. In order to detect TCWP degradation timely, this paper proposes a vibration-based monitoring scheme of the ACMGB, where structural vibration information are collected by accelerometers and dynamic strain guages at the bottom of girders in mid-span. These monitoring data are then used for identifying transverse mode shape of the multi-beam system and its derivated index in order to evaluate TCWP. This scheme has been implemented on three adjacent ACMGBs in Tongji Road Viaduct and the preliminary analysis of monitoring data proves the effectiveness and rationality of the monitoring scheme proposed in this paper, which has the potential of the TCWP evaluation.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-09T08:00:00Z
      DOI: 10.1142/S0219455421500437
       
  • Free Vibrations of Steel–Concrete Composite Beams by the Dynamic
           Direct Stiffness Method
    • Authors: Qikai Sun, Nan Zhang, Xiao Liu, Xiaoyan Tao
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A new dynamic direct stiffness method for analyzing the natural vibration characteristics of steel–concrete composite beams (SCCBs) is proposed, which considers the effect of partial interaction between the interface of the concrete slab and steel beam. The advantage of the method is that exact solutions can be obtained due to no introduction of approximated displacement and/or force fields in the derivation. Besides, the method is especially useful for the dynamic analysis of SCCBs with axial variable stiffness under four common boundary conditions. The proposed method is validated by comparing with the theoretical and experimental results available in the literature. Finally, the effects of different boundary conditions, shear connection, cross-sectional stiffness ratio, and other parameters upon the frequencies of the beam are discussed in detail.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-09T08:00:00Z
      DOI: 10.1142/S0219455421500498
       
  • Stability of Layered Structures with Hybridized Configuration by Means of
           a Reddy-Type Higher-Order Finite Element Formulation
    • Authors: Zhen Wu, Jie Zhou, Zhengliang Liu, Rui Ma, Xiaohui Ren
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      To make use of the merit of designability, each lamina in layered structures may possess diverse materials and geometry to realize specific application. For the hybridized structures, geometry and material properties relative to the middle surface are generally unsymmetrical, which have a significant impact on stability. Some models might lose capability to deal with such issues, so that these issues are less reported. Within the developed models, Reddy’s model possesses merit of simplicity and efficiency, so a Reddy-type higher-order zig-zag model is constructed by utilizing the proposed zig-zag function (ZZF). Instead of the standard finite element formulation using the principle of minimum potential energy, the three-field Hu–Washizu (HW) mixed variational principle is employed to acquire the finite element formulation which can meet the harmonious conditions of transverse shear stress at the interface of adjacent layers. By investigating buckling behaviors of hybridized structures, performance of the proposed finite element formulation is appraised by comparing with the results obtained from the three-dimensional (3D) model as well as other models. Effect of boundary conditions (BCs), material properties, and span-to-thickness ratio on the buckling loads is also studied in detail. Numerical results show that buckling loads of hybridized structures are significantly impacted by the chosen parameters. The results acquired from proposed model are in very good agreement with those obtained from the layerwise (LW) model and the 3D finite element results.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2021-01-06T08:00:00Z
      DOI: 10.1142/S0219455421500450
       
  • Adaptive Amplifier for a Test Vehicle Moving Over Bridges: Theoretical
           Study
    • Authors: Y. B. Yang, Z. L. Wang, K. Shi, H. Xu, J. P. Yang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A vibration amplifier is first proposed for adding to a test vehicle to enhance its capability to detect frequencies of the bridge under scanning. The test vehicle adopted is of single-axle and modeled as a single degree-of-freedom (DOF) system, which was proved to be successful in previous studies. The amplifier is also modeled as a single-DOF system, and the bridge as a simple beam of the Bernoulli–Euler type. To unveil the mechanism involved, closed-form solutions were first derived for the dynamic responses of each component, together with the transmissibility from the vehicle to amplifier. Also presented is a conceptual design for the amplifier. The approximations adopted in the theory were verified to be acceptable by the finite element simulation without such approximations. Since road roughness can never be avoided in practice and the test vehicle has to be towed by a tractor in the field test, both road roughness and the tractor are included in the numerical studies. For the general case, when the amplifier is not tuned to the vehicle frequency, the bridge frequencies can better be identified from the amplifier than vehicle response, and the tractor is helpful in enhancing the overall performance of the amplifier. Besides, the amplifier can be adaptively adjusted to target and detect the bridge frequency of concern. For the special case when the amplifier is tuned to the vehicle frequency, the amplifier can improve the vehicle performance by serving as a tuned mass damper, as conventionally known. This case is of limited use since it does not allow us to target the bridge frequencies. Both bridge damping and vehicle speed are also assessed with their effects addressed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-29T08:00:00Z
      DOI: 10.1142/S0219455421500425
       
  • An Efficient Dimension-Adaptive Numerical Integration Method for
           Stochastic Dynamic Analysis of Structures with Uncertain Parameters
    • Authors: Helu Yu, Bin Wang, Zongyu Gao, Yongle Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper presents a novel dimension-adaptive numerical integration method for dynamic analysis of structures with stochastic parameters subjected to deterministic excitations. First, an efficient dimension-adaptive algorithm is proposed to detect the importance of each random parameter involved in the structural model, based on which the quadrature nodes used for numerical integration can be collocated more reasonably. Then, the Gaussian quadrature formulas are used to evaluate the structural response statistics. To further improve the robustness and efficiency of the proposed method, the dimension-adaptive integration is only used to calculate the structural displacement response statistics. The velocity and acceleration response statistics are further evaluated using the finite difference formulas based on the concept of stochastic difference. Such a strategy is especially attractive when evaluating the response statistics of the derivative processes requires more quadrature nodes than that of the original process. Finally, two numerical examples encountered in civil engineering, including a shear frame with stochastic parameters subjected to a seismic ground motion and an Euler beam with unidimensional stochastic field of material properties (discretized via the Karhunen–Loève expansion) subjected to a moving load are studied to illustrate the performance of the proposed method. Via the numerical results, the accuracy and efficiency of the proposed method are verified.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-28T08:00:00Z
      DOI: 10.1142/S0219455421500358
       
  • Stability of Stainless Steel I-Section Beam-Columns at Elevated
           Temperatures
    • Authors: Merih Kucukler, Zhe Xing, Leroy Gardner
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      With the growing use of stainless steel in the construction and offshore industries, there is an increasing interest and need to study the performance of stainless structures at elevated temperatures. The behavior and design of stainless steel I-section beam-columns in fire is investigated in this paper, addressing a scarcity of previous research on this topic. Finite element (FE) models of stainless steel beam-columns, able to replicate their response at elevated temperatures, are created and validated; the validated models are then used to perform parametric studies to generate extensive benchmark structural performance data. The design rules set out in the European structural steel fire design standard EN 1993-1-2 are assessed and shown to provide rather inaccurate and often unsafe ultimate strength predictions for stainless steel I-section beam-columns in fire. New fire design rules for stainless steel beam-columns are put forward. It is shown that the new proposals are able to offer improved accuracy and design efficiency relative to the EN 1993-1-2 beam-column design rules. The reliability of the proposed design rules is also verified on the basis of the fire design reliability criteria set out by Kruppa [Eurocodes–Fire parts: Proposal for a methodology to check the accuracy of assessment methods, CEN TC 250, Horizontal Group Fire, Document no: 99/130 (1999)], thereby demonstrating the suitability of the proposed design rules for inclusion in the upcoming revised version of EN 1993-1-2.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-28T08:00:00Z
      DOI: 10.1142/S0219455421500371
       
  • Stochastic Extended Finite Element Implementation for Natural Frequency of
           Cracked Functionally Gradient and Bi-Material Structures
    • Authors: Ahmed Raza, Himanshu Pathak, Mohammad Talha
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this work, stochastic perturbation-based vibration characteristics of cracked bi-material and functionally graded material (FGM) domain with uncertain material properties are investigated using the extended finite element method. The level set function is implemented to track the geometrical discontinuities. The partition of unity-based extrinsic enrichment technique is employed to model the crack and material interface. The exponential law is used to model the graded material properties of FGM. The First-order perturbation technique (FOPT) is implemented to predict the standard deviation of natural frequency for the given uncertainties in the material properties. The numerical results are presented to show the effect of geometrical discontinuities and material randomness on vibration characteristics.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-28T08:00:00Z
      DOI: 10.1142/S0219455421500449
       
  • Breathing Crack Localization in Structures Based on Principal Component
           Analysis of Forced Vibration Responses
    • Authors: J. Prawin
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The identification of a breathing crack is a highly challenging inverse problem in structural health monitoring. A novel output-only damage diagnostic technique based on Principal Component Analysis (PCA) is proposed for breathing crack identification in structures excited by harmonic excitation. The proposed approach basically utilizes the residues obtained from PCA of the forced acceleration-time history responses of the structure for breathing crack identification. In this approach, the traditional single-tone, bitone and as well as multi-tone harmonic excitations are considered as input to the structure while exploring the residues of the responses for breathing crack identification. A new Damage Localization Index (DLI) based on the Fourier spectrum amplitudes of the nonlinear sensitive features (i.e. buried in residues), measured at varied locations spatially across the structure is proposed for breathing crack localization. The robustness and effectiveness of the proposed PCA-based breathing crack localization approach is verified through both numerical and experimental studies.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-24T08:00:00Z
      DOI: 10.1142/S0219455421500413
       
  • Periodic Response and Stability of a Maglev System with Delayed Feedback
           Control Under Aerodynamic Lift
    • Authors: Han Wu, Xiao-Hui Zeng, Ding-Gang Gao
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this research, the periodic response and stability of a nonlinear maglev system under the combined effects of steady and unsteady aerodynamic lifts is investigated, considering time delay in the feedback control loop. First, a nonlinear maglev system with a single levitation point that accounts for the nonlinearity of the electromagnetic force, time delay in the feedback control loop, and effect of aerodynamic lift is established. Then the periodic solutions of the maglev system with aerodynamic lift and time delays are obtained by an incremental harmonic balance analysis, in which the explicit time-delay action matrices used indicate that the effect of time delay on the response of the maglev system is periodic. The stability of the periodic solutions based on a finite difference continuous time approximation method and Floquet theory is studied, from which the critical time delay is obtained. Also, the relationship between the periodic vibration amplitude and the time delay is examined, along with the steady aerodynamic lift coefficient, and frequency of the unsteady aerodynamic lift, as well as the variation of critical delay with respect to the position feedback and velocity feedback with the control gain parameters. In addition, the stability boundary for the simultaneous time-delayed position and velocity feedback is obtained.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-23T08:00:00Z
      DOI: 10.1142/S0219455421500401
       
  • Thermal Postbuckling of Temperature-Dependent Functionally Graded
           Nanocomposite Annular Sector Plates Reinforced by Carbon Nanotubes
    • Authors: Raheb Gholami, Reza Ansari
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this study, the thermal buckling and postbuckling of functionally graded (FG) nanocomposite annular sector plates reinforced by carbon nanotubes (CNTs) are numerically analyzed. The effective material properties of FG nanocomposite are temperature-dependent (TD) and evaluated via the modified micromechanical method and rule of mixture. Based on the higher-order shear deformation theory (HSDT) and using the principle of virtual work and variational differential quadrature (VDQ) approach, the unified weak form of discretized nonlinear governing equilibrium equations is derived. Then, by using the linear part of equations and solving the derived eigenvalue problem, the critical temperature rise and associated mode shapes are obtained, which are used as the initial guess in solving the nonlinear thermal postbuckling problem. The pseudo-arc-length method and an iterative solver are employed to obtain the nonlinear thermal postbuckling equilibrium path of the FG nanocomposite annular sector plates. The influences of geometrical parameters, boundary conditions (BCs), CNT volume fraction, and CNT distribution pattern on the critical temperature rise and thermal postbuckling behavior of the FG nanocomposite annular sector plates are evaluated and discussed. Also, comparisons are made between the results considering the TD and temperature-independent (TID) properties. It is demonstrated that for higher values of sector angle, the effect of sector angle on the critical temperature rise and thermal postbuckling path is negligible. Moreover, by increasing the sector angle, the effect of BCs of straight edges vanishes, and the critical temperature rise and thermal postbuckling curves of for BCs of CSCS and SCSC approach those for CCCC and SSSS ones.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-22T08:00:00Z
      DOI: 10.1142/S0219455421500267
       
  • Nonlinear Blast Responses of Thin Shell Roof Over Long Span Structures
    • Authors: Jake Rennie, Sakdirat Kaewunruen, Charalampos Baniotopoulos
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper adopts both explicit and implicit finite element methods in a specialist package LS-DYNA to investigate the nonlinear, dynamic response of a long span shell roof structure when subjected to blast loading. Parametric studies have been carried out on blast loaded laminated glass plates with reference to experimental results obtained by European researchers. A case study that has been chosen is a light rail station in The Netherlands called The Erasmusline. Following the detonation of 15[math]kg TNT charge, explicit analysis showed breakage surrounding the rigid supports along the edge beam where modal vibrations are restrained. An implicit analysis has confirmed the resonances in global eigen-frequencies where most blast damage is localized around the roof canopy hence producing cracking and potential glass detachment from the panels without full structural demolition. This insight from this study will inform structural engineers about the potential modes of failure and preventative strategies to minimize further secondary losses of life or assets from a terrorist attack.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-21T08:00:00Z
      DOI: 10.1142/S0219455421500310
       
  • Damage Sensitive PCA-FRF Feature in Unsupervised Machine Learning for
           Damage Detection of Plate-Like Structures
    • Authors: Pei Yi Siow, Zhi Chao Ong, Shin Yee Khoo, Kok-Sing Lim
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Damage detection is important in maintaining the integrity and safety of structures. The vibration-based Structural Health Monitoring (SHM) methods have been explored and applied extensively by researchers due to its non-destructive manner. The damage sensitivity of features used can significantly ect the accuracy of the vibration-based damage identification methods. The Frequency Response Function (FRF) was used as a damage sensitive feature in several works due to its rich yet compact representation of dynamic properties of a structure. However, utilizing the full size of FRFs in damage assessment requires high processing and computational time. A novel reduction technique using Principal Component Analysis (PCA) and peak detection on raw FRFs is proposed to extract the main damage sensitive feature while maintaining the dynamic characteristics. A rectangular Perspex plate with ground supports, simulating an automobile, was used for damage assessment. The damage sensitivity of the extracted feature, i.e. PCA-FRF is then evaluated using unsupervised [math]-means clustering results. The proposed method is found to exaggerate the shift of damaged data from undamaged data and improve the repeatability of the PCA-FRF. The PCA-FRF feature is shown to have higher damage sensitivity compared to the raw FRFs, in which it yielded well-clustered results even for low damage conditions.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-19T08:00:00Z
      DOI: 10.1142/S0219455421500280
       
  • Dynamic Reliability Evaluation by First-Order Reliability Method
           Integrated with Stochastic Pseudo Excitation Method
    • Authors: Siyu Zhu, Tianyu Xiang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The stochastic pseudo excitation method (SPEM), which is based on the principle of pseudo excitation method (PEM), is introduced to represent the randomness of dynamic input in which the amplitude of excitation is adopted as a random variable. Based on the mathematic definition of power spectral density, a physical interpolation of the SPEM is discussed. Even if one random variable is involved in calculation, the effects of the uncertainties are required to be investigated. The SPEM offers a simple but quite effective way to solve the dynamic reliability problem. Through integrating the new algorithm into first-order reliability method (FORM), the dynamic reliability of uncertain structure subjected to random excitation is studied. A linear oscillator with three types of white noise is adopted to verify the SPEM for dynamic reliability of linear random vibration analysis. Also, the accuracy and efficiency of SPEM to handle the multi-degree-of-freedom structure is investigated in this paper.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-12T08:00:00Z
      DOI: 10.1142/S0219455421500243
       
  • An Efficient Non-Iterative Hybrid Method for Analyzing
           Train–Rail–Bridge Interaction Problems
    • Authors: Kang Shi, Xuhui He, Yunfeng Zou, Zhi Zheng
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The dynamic interaction problem for the train–rail–bridge (TRB) systems presents a computational challenge, especially for the analysis of large-size TRB coupling systems. To address this issue, an efficient non-iterative hybrid method (NHM) is proposed. With this method, the integrated TRB system is divided into three subsystems, i.e. the train subsystem, the rail subsystem, and the bridge subsystem. Based on the individual subsystems, a multi-step[math] technique is adopted in which a fine time step is used to analyze the high-frequency coupling vibration for the train and rail subsystems, and a coarse time step is adopted to calculate the low-frequency coupling vibration for the rail and bridge subsystem. Additionally, Zhais explicit integral method is used to predict the displacement of the wheelsets and the rail at the current time step before using the Newmark method. The proposed method incorporates the advantages of Zhai’s explicit method and the MS technique to avoid the iteration that may be required for the train–rail coupled analysis. The simulation fidelity and computational efficiency of the proposed method are demonstrated in the analysis of two examples of typical high-speed railway bridges. It was demonstrated that the proposed method can significantly enhance the computational efficiency, while maintaining a higher precision with a larger time step in comparison with other existing methods.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-12T08:00:00Z
      DOI: 10.1142/S0219455421500292
       
  • Parameter Influences on Rail Corrugation of Metro Tangential Track
    • Authors: Zhiqiang Wang, Zhenyu Lei
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Rail corrugation can reduce riding comfort by vibration and noise, and even cause running accident. In this paper, the vehicle–track coupled dynamic model was developed for a metro’s tangential track considering the wear in rail materials. The influences of different track structure parameters and vehicle speed on the generation and development of rail corrugation of the tangential track were analyzed using the developed model by the control variable method. The results show that for different parameters, the friction power in wheel–rail contact patch fluctuates with time, but the overall fluctuation range is relatively uniform. Meantime, an analysis of one-third octave curves of the friction power reveals that the characteristic frequencies of friction power are mainly concentrated in the middle and low frequency bands. At the dominant characteristic frequency, the longitudinal stiffness and damping of fasteners, and lateral and vertical damping of fasteners have less influence on rail corrugation, while the lateral and vertical stiffnesses of fasteners, spacing of fasteners, wheel–rail friction coefficient and vehicle speed have greater effect on rail corrugation. The changes in vertical stiffness and spacing of fasteners will cause the characteristic frequency of friction power to be offset, resulting in a shift from 80[math]Hz to 100[math]Hz, which will further lead to rail corrugation of the corresponding wavelength. Thus, it can be concluded that the vertical stiffness and spacing of fasteners have an important impact on the generation and development of rail corrugation at the specific frequency. Besides, the variations of the other variables bring little change to the characteristic frequencies of friction power as well as on rail corrugation. The mechanism of parameters unveiled here provides some guides for the parameter optimization problem on restraining the generation or development of rail corrugation on the tangential track.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-10T08:00:00Z
      DOI: 10.1142/S0219455421500346
       
  • Feasibility Study of Super-Long Span Bridges Considering Aerostatic
           Instability by a Two-Stage Geometric Nonlinear Analysis
    • Authors: Jiunn-Yin Tsay
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      To meet the need of constructing fixed cross strait links, super-long span bridge with a main span over 2 000[math]m is considered as a candidate for their ability to cross deep and wide straits. To this end, some super-long span bridges with proper cable and girder systems were previously proposed and studied. The major design considerations are aimed at adopting new cable material, increasing the entire rigidity of the bridge, stabilizing the dynamic characteristics, strengthening the deck sections, etc. In this paper, a brief review of main cable and girder system is first given of the concepts previously proposed for the design of super-long span bridges. Then some typical examples are studied, focused on various issues related to the design of super-long span bridges, including composite cable, the unstressed length and tension force of the main cable, the stiffness and mass effects of the deck on critical wind speed, and the critical wind speed of various cable systems. The most challenges in super-long span bridges are to solve aerostatic and aerodynamic instability at required design wind speed. In this connection, the wind-induced aerostatic instability of super-long span bridges is studied by a two-stage geometric nonlinear analysis for dead loads and wind loads. The developed program adopted herein for geometric nonlinear analysis was verified and confirmed before. The proposed methods (i.e. composite cable, slotted girder, increasing deck stiffness and mass, cable layout, etc.) obtained for all the examples are in agreement with this study, which indicates applicability of the design approaches presented.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-09T08:00:00Z
      DOI: 10.1142/S0219455421500334
       
  • Explicit Expressions for Buckling Analysis of Thin-Walled Beams Under
           Combined Loads with Laterally-Fixed Ends and Application to Stability
           Analysis of Saw Blades
    • Authors: Van Binh Phung, Ngoc Doan Tran, Viet Duc Nguyen, V. S. Prokopov, Hoang Minh Dang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper studies the critical issue of thin-walled beams with laterally fixed ends. The method for defining the formulae of twist moment for the beams subjected to combined loads was elucidated. Based on this, the governing differential equations of the beam were developed. The procedure for determining the critical state of the beam by the energy method was presented. With this procedure, the critical state of the beam concerned under three types of loadings such as axial force [math], bending moment [math] and distributed load [math] (or concentrated load [math]) was examined deliberately. The outcomes were presented in explicit closed-form, which can be illustrated in 2D and 3D graphs. Also, the analytical solution obtained was in agreement with the numerical one obtained by the commercial software NX Nastran. Furthermore, the analytical solutions were applied straightforwardly to explore the stability and design optimization of the tooth-blade for the new frame-type saw machine under an eccentric load. The result can also be promisingly used to study problems of thin-walled beams with laterally fixed ends subjected to other types of loads.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-07T08:00:00Z
      DOI: 10.1142/S0219455421500322
       
  • Experimental Study on Dynamic Amplification Factor of Simple-Supported
           Reinforced Concrete Beams Under Impact Loading Generated by an Impulse
           Hammer
    • Authors: Xue-Qian Wu, Bo Zhong, Yang Lv, Zhong-Xian Li, Nawawi Chouw
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The empirical formulas of dynamic amplification factor (DAF) specified in current bridge codes only consider the span or fundamental frequency of reinforced concrete (RC) girders in highway. Although investigations have been carried out on different bridges with considering the road roughness, vehicle–bridge interactions and travelling velocity, but most of them have been done numerically. In this study, experimental study of DAF was carried out on three simple-supported RC beams with different fundamental frequencies and different damage stages, i.e. without damage, cracked and yielded. Impulse hammer with four hammer heads of different hardness, i.e. black, red, green and brown, were used to generate impact forces with increasing duration. The impact tests were first carried out on the RC beams without any damage by impact hammer with different hammer heads. Then the RC beams were loaded by a concentrated static force at the mid-span to crack. Impact tests with different hammer heads were repeated on the cracked RC beams. Finally, the cracked beams were further loaded by a concentrated static force to yield of the longitudinal reinforcement. The impact tests were repeated on the yielded beams again. Load cells installed at the supports of the RC beams were used to measure the reaction force generated by the hammer, then DAF was calculated directly by dividing the peak reaction force with the peak impact force. Data obtained from tests, theoretical analysis and specification in codes were compared to examine the DAFs. Results show that the ratio of duration of the impact force and the period of the beams performed a significant effect on the DAFs of the beams.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-07T08:00:00Z
      DOI: 10.1142/S021945542150036X
       
  • Dynamic Stability of Simply Supported Beams With Multi-Harmonic Parametric
           Excitation
    • Authors: Chao Xu, Zhengzhong Wang, Baohui Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Determination of the regions of dynamic instability has been an important issue for elastic structures. Under the extreme climate, the external load acting on structures is becoming more and more complicated, which can induce dynamic instability of elastic structures. In this study, we explore the dynamic instability and response characteristics of simply supported beams under multi-harmonic parametric excitation. A numerical approach for determining the instability regions under multi-harmonic parametric excitation is developed here by examining the eigenvalues of characteristic exponents of the monodromy matrix based on the Floquet theorem, and the fourth-order Runge–Kutta method is used to calculate the dynamic responses. The accuracy of the method is verified by the comparison with classical approximate boundary formulas of dynamic instability regions. The numerical results reveal that Bolotin’s approximate formulas are only applicable to the low-order instability regions with a small value of the excitation parameter of simple parametric resonance. Multi-harmonic parametric excitation can significantly change the dynamic instability regions, it may cause parametric resonance on beams for longitudinal complex periodic loads. The influence of frequency and number of multiply harmonics on the parametrically excited vibration of the beam is explored. High-order harmonics with low-frequency have positive effects on the stable response characteristics for multi-harmonic parametric excitation. This paper provides a new perspective for the vibration suppression of parametric excitation. The developed procedure can be used for multi-degree-of-freedom (MDOF) systems under complex excitation (e.g. tsunami waves and strong winds).
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-12-05T08:00:00Z
      DOI: 10.1142/S0219455421500279
       
  • Seismic Control of a Self-Anchored Suspension Bridge Using Fluid Viscous
           Dampers
    • Authors: Dongming Feng, Jingquan Wang
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      A self-anchored suspension bridge balances forces internally without external anchorage requirements, making it suitable for sites where anchorages would be difficult to construct. It often adopts either a full-floating or a semi-floating tower-girder connection system, which may result in large displacement responses along bridge longitudinal direction during earthquakes. This study investigated the efficacy of using the fluid viscous damper (FVD) for seismic control of a single-tower self-anchored suspension bridge. First, the energy dissipation behaviors of the FVD under sinusoidal excitations were studied. It revealed that besides the damper parameters (i.e. damping coefficient and velocity exponent) of an FVD itself, the energy dissipation capacity also relies on the characteristics of external excitations. Therefore, optimum damper parameters added to a structure should be determined on a case-by-case basis. Parametric study was then carried out on the prototype bridge, which indicated a tendency of decreasing the longitudinal deck/tower displacements and tower forces with increasing damping coefficient [math] and decreasing velocity exponent [math]. Compared with the linear FVD, the nonlinear FVD with a smaller velocity exponent can develop more rectangular force-displacement loops and thus achieve better energy dissipation performance. With selected optimum damper parameters (i.e. [math][math]kN[math]m[math][math]s[math] and [math]) for the two FVDs added between the deck and the tower, the longitudinal deck and tower displacements could be reduced by 54%, while the peak bending moment and shear force at the tower base could be reduced by 30% and 19%, respectively. It is concluded that the nonlinear FVD can provide a simple and efficient solution to reduce displacement responses of self-anchored suspension bridges while simultaneously reducing the bending moment and shear force in the tower.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-28T08:00:00Z
      DOI: 10.1142/S0219455421500255
       
  • Structural Behaviors of Integrally-Jointed Plywood Columns with Knot
           Defects
    • Authors: Zhuoyang Xin, Joseph Gattas
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Modern factory automation is enabling the economic production of timber building components with sophisticated integral mechanical joints. This paper investigates the governing compressive failure mechanisms of full-length integrally-jointed plywood box columns, and in particular seeks to understand the interaction between localized material knot defects, integral box joint capacity, and column strength. A new critical failure mechanism is identified based on experimental observations and numerical analysis of sections with varying sizes of knot defect, with column capacity governed by defect-induced transverse loading of integral box joints. Column capacity was shown to improve with localized joint strengthening in knot-defective regions, or with a defect-adaptive fabrication procedure that avoids identified defects during component plate machining. The new failure mechanism was also combined with prior understanding of plate buckling and pop-off failure mechanisms to propose an overall failure process for integrally-jointed plywood columns. Results from this paper can also inform development of other types of integrally-jointed thin-walled structures.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-26T08:00:00Z
      DOI: 10.1142/S021945542150022X
       
  • A New Damage Detection Method for Special-Shaped Steel Arch Bridges Based
           on Fractal Theory and the Model Updating Technique
    • Authors: X. X. Cheng, G. Wu, L. Zhang, F. B. Ma
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this paper, an innovative two-level damage detection method applicable to real-world online structural health monitoring (SHM) systems is proposed for in-service large steel arch bridges. The method consists of Level 1 damage detection practice that includes strain data acquisition and damage location using the damage index based on the fractal theory, and Level 2 damage detection practice that includes acceleration sample acquisitions and dynamic model updating to quantify the damage. A numerical case study of the Yingzhou bridge based on various damage cases demonstrated the effectiveness of the proposed damage detection method. It is revealed that Level 1 damage detection is sufficiently robust against the standard measurement noise and normal temperature variations. The study results also indicated that the accuracy of Level 2 damage detection largely depends on whether the initial structure imperfections are taken into account, and whether the utilized model updating method is effective under model errors.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-25T08:00:00Z
      DOI: 10.1142/S0219455421500309
       
  • Undrained Seismic Stability of Dual Unsupported Circular Tunnels Subjected
           to Surcharge Loading
    • Authors: Rui Zhang, Gaoqiao Wu, Minghua Zhao, Ming Lei
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Undrained seismic stability of dual unsupported circular tunnels was investigated in this work using a self-developed code for adaptive finite element limit analysis. The so-called pseudo-static method was used to simulate the seismic effects during an earthquake. Accurate upper and lower bounds of seismic stability factor [math] were obtained by using an adaptive remeshing technique incorporated in the code. Comprehensive parametric studies of the problem variables, including the horizontal seismic coefficient [math], the relative spacing ratio [math]/[math], the relative depth ratio [math]/[math] and the strength ratio [math]/[math] were performed to provide dimensionless design tables for practical uses. In addition, visualized results from AFELA were summarized to reveal how the failure mechanism of dual tunnels would evolve with varying problems variables. Numerical results showed that both the stability and failure mechanism of dual tunnels can be much affected by seismic effects which should be carefully considered for a reasonable design in earthquake zones.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-25T08:00:00Z
      DOI: 10.1142/S0219455421710012
       
  • Failure Behavior of Double-Layer-Domes Subjected to Impact
    • Authors: E. Nazari, B. Shekastehband
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The dynamic failure behavior of double-layer-domes subjected to impact is studied numerically through the nonlinear finite element software LS-DYNA. The parameters considered in this work include the mass, velocity, and size of impactor, impact direction, roof weigh, geometric imperfection, rise-to-span ratio, and depth of dome. The dynamic time-history response and energy conversion of the structure are utilized to distinguish between the failure mechanism types. For the cases studied, it is found that failure of the structures falls into one of the three categories: (1) local shear failure, (2) partial progressive failure, and (3) full progressive failure. Non-failure case dominates the dome response when the kinetic energy of the impactor is small enough, and the structure can convert most of the kinetic energy into the strain energy, thereby absorbing the impact. Local shear failure occurs in a double-layer-dome when an impactor with very high kinetic energy strikes the dome. For an impactor striking with a mass of 5 to 300[math]ton and a velocity of 50 to 120[math]m/s, the double-layer-dome studied will suffer from partial progressive failure. Varying mass and velocity of the impactor in the range of 1 to 300[math]ton and 200 to 400[math]m/s, respectively, results in a tendency of the dome to exhibit local shear failure. Although impact direction does not cause a change in the failure mechanism type, there is a reduction in the severity of failure of the system as the impact angle increases. Roof weight has no dominant effect on the failure mechanism of the double-layer-dome. A small initial member imperfection with amplitude 0.001[math] does not change the progressive failure type. A large member imperfection of 0.01[math] triggers member buckling and leads to local shear failure of the dome. Except for some loading cases, the change in the rise to span ratio and depth of the dome does not seriously affect the failure mode.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500152
       
  • Temperature-Dependent Vibration of Various Types of Sandwich Beams with
           Porous FGM Layers
    • Authors: Mohsen Rahmani, Sajjad Dehghanpour
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      By using a high order sandwich beams theory which is modified by considering the transverse flexibility of the core, free vibration characteristics of two models of sandwich beams are studied in this paper. In type-I, functionally graded layers coat a homogeneous core, and in type-II, an FG core is covered by homogeneous face sheets. To increase the accuracy of the model of the FGM properties, even and uneven porosity distributions are applied, and all materials are considered temperature-dependent. Nonlinear Lagrange strain and thermal stresses of the face sheets and in-plane strain of the core are considered. To obtain the governing equations of motion, Hamilton’s principle is used and a Galerkin method is used to solve them for simply supported and clamped boundary conditions. To verify the results of this study, they are compared with the results of literatures. Also, the effect of variation of temperature, some geometrical parameters and porosities on the frequency are studied.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500164
       
  • Numerical and Experimental Analyses of Free and Forced Vibration of
           Thin-Walled Beams
    • Authors: Wassim Jrad, Foudil Mohri, Guillaume Robin, El Mostafa Daya
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The flexural–torsional vibration behavior of unrestrained and braced thin-walled beams is investigated by experimental and finite elements approaches. In the experimental part, tests in free and forced vibrations of thin walled beams with arbitrary sections are analyzed. By the help of an instrumental hammer test and a shaker machine, the natural frequencies and the response spectra of the beams are extracted in the range 1–400[math]Hz. Beam displacements are measured by some accelerometer transducers. The behavior is also investigated by the finite element method. In mesh process, 3D beams are adopted and an additional DOF is affected to the warping. The model is implemented in a home-made model. The numerical and experimental results are compared to numerical simulations of a commercial code. Test results and numerical simulations of the present model agree well. The model seems to be accurate especially in the presence of higher vibration and coupled modes.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500188
       
  • Energy Similitude Correction Method for Free Vibration of Cylinders
    • Authors: Lilin Zhou
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Similitude theory has been applied to design scale models in many fields of engineering. As for free vibration of cylinders, the wall thickness is too thin to manufacture scale model, which leads to similitude distortion. The aim of this study is to correct the similitude distortion and establish the distorted similitude relationship for free vibration of cylinders. First, the complete and partial similitude relationships are deduced while the similitude distortion of wall thickness is discussed. Then, with analysis of similitude for energy, an equation with prediction of modal frequencies for prototype is established and the energy similitude correction method is proposed. Finally, through numerical examples, this method is verified and the influence of wall thickness variation on the accuracy of the proposed method is analyzed.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-20T08:00:00Z
      DOI: 10.1142/S0219455421500231
       
  • A Method to Estimate Dynamic Buckling Response of an Unstiffened Plate
           Elastically Restrained Along all Edges Under In-Plane Impact
    • Authors: Bin Yang, Kunkun Fu, Yan Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      Unstiffened plates in structures are usually welded or fastened to supporting members, providing rotational restraint stiffness to the plate. Previous studies have shown that neglect of rotational restraint stiffness at the edges of a plate in a structure can introduce deviations in the analysis of dynamic elastic buckling. In this study, the in-plane impact-induced dynamic elastic buckling responses of isotropic imperfect unstiffened plates with four elastically restrained edges are analytically investigated, based on the large-deflection theory of thin plate. The evolution of the peak deflection predicted by the proposed analytical method is found to be consistent with the responses available from the literature. Then the method is further used to estimate the deformation map of an unstiffened plate with four elastically restrained edges, and the effects of rotational restraint stiffness, initial geometric imperfection and shock duration on the dynamic buckling response of the plate are examined. The results show that the critical dynamic buckling load and the maximum deflection response of the plates are significantly influenced by the rotational restraint stiffness as well as the first-order initial geometric imperfection, and thus cannot be neglected in the analysis of dynamic buckling.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-11T08:00:00Z
      DOI: 10.1142/S0219455421500218
       
  • Analysis of Factors Affecting the Accuracy of Moving Force Identification
    • Authors: Zhen Chen, Lu Deng, Xuan Kong
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      In this study, the influence of the static component in the total force and the effective frequency bandwidth on the accuracy of force identification has been investigated. The acceleration and bending moment responses at different locations of a simply supported beam under different moving forces are numerically measured. The fast Fourier transformation is also introduced to analyze the frequency-domain component of the dynamic responses of the beam. Simulation results show that the dynamic characteristics of the vehicle, such as the frequency of dynamic vehicle load, have significant effect on the proportion of static component in the total vehicle load; the higher the proportion of static component in the total force, the higher the identification accuracy. In addition, the wider the effective frequency bandwidth, the higher the identification accuracy. The numerical results also show that both the proportion of static component in the total force and the effective frequency bandwidth vary with the type and location of measurement. To more accurately identify the moving force, it is necessary to analyze first the static component and frequency characteristics of the measured responses and to select appropriate type and location of measurement.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-03T08:00:00Z
      DOI: 10.1142/S021945542150019X
       
  • A Pyramidal Lattice Frame: Pathways to Inversion
    • Authors: Yue Guan, Lawrence N. Virgin
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      This paper considers the load–deflection behavior of a pyramid-like, shallow lattice structure. It consists of four beams that join at a central apex and when subject to a lateral load, it exhibits a propensity to snap-through: a classical buckling phenomenon. Whether this structural inversion occurs, and the routes by which it happens, depends sensitively on geometry. Given the often sudden nature of the instability, the behavior is also examined within a dynamics context. The outcome of numerical simulations are favorably compared with experimental data extracted from the testing of three-dimensional (3D)-printed specimens. The key contributions of this paper are that despite the continuous nature of the physical system, its behavior (transient and equilibria) can be adequately described using a discrete model, and the paper also illustrates the utility of 3D-printing in an accessible research context.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-11-03T08:00:00Z
      DOI: 10.1142/S0219455421500206
       
  • Control of Magnetoelectric Load to Maintain Stable Compression Ratio for
           Free Piston Linear Engine Systems
    • Authors: Bo Yang, Chenheng Yuan, Jiahui Li
      Abstract: International Journal of Structural Stability and Dynamics, Ahead of Print.
      The free piston linear engine system (FPLE) is considered as a promising powerplant, which has the advantages such as compact structure, short transfer path and variable compression ratio (CR) because the crank connecting rod is removed. However, the absence of crank-connecting rod inevitably produces uncertainty to the stable operation of the FPLE. A control system of the piston motion regulating for the FPLE is necessary. In this paper, the nonlinear dynamic model simulating the piston motion in a dual-piston FPLE is derived based on energy and force balance. The feasibility of the dynamic model is verified by experiment and simulation results. Based on instability mechanism analysis, a magnetoelectric load controller with motion stroke feedback is designed to maintain the piston position in a predefined CR by regulating the magnetoelectric force. The proposed magnetoelectric load controller is shown to have good control performance for the FPLE. The piston is always stabilized at the predefined position after a short adjustment time. The time of eliminating disturbance for the operation process is less than the start process. Furthermore, the increase in disturbance will result in the increase of time for adjustment.
      Citation: International Journal of Structural Stability and Dynamics
      PubDate: 2020-10-30T07:00:00Z
      DOI: 10.1142/S0219455421500176
       
 
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