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  Subjects -> ENGINEERING (Total: 2278 journals)
    - CHEMICAL ENGINEERING (191 journals)
    - CIVIL ENGINEERING (183 journals)
    - ELECTRICAL ENGINEERING (103 journals)
    - ENGINEERING (1205 journals)
    - ENGINEERING MECHANICS AND MATERIALS (385 journals)
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ENGINEERING (1205 journals)            First | 1 2 3 4 5 6 7 | Last

Showing 401 - 600 of 1205 Journals sorted alphabetically
IET Microwaves, Antennas & Propagation     Hybrid Journal   (Followers: 30)
IET Optoelectronics     Hybrid Journal   (Followers: 1)
IET Radar, Sonar & Navigation     Hybrid Journal   (Followers: 27)
IET Renewable Power Generation     Hybrid Journal   (Followers: 10)
IET Science, Measurement & Technology     Hybrid Journal   (Followers: 2)
IET Signal Processing     Hybrid Journal   (Followers: 16)
IETE Journal of Research     Open Access   (Followers: 11)
IETE Technical Review     Open Access   (Followers: 11)
IIE Transactions     Hybrid Journal   (Followers: 2)
IIUM Engineering Journal     Open Access  
Implementation Science     Open Access   (Followers: 14)
Indian Journal of Biotechnology (IJBT)     Open Access   (Followers: 2)
Indonesian Journal of Science and Technology     Open Access  
Industrial Data     Open Access   (Followers: 1)
Industrie et Technologies     Full-text available via subscription   (Followers: 15)
Informatik-Spektrum     Hybrid Journal   (Followers: 2)
Ingeniare : Revista Chilena de Ingenieria     Open Access   (Followers: 1)
Ingenieria     Open Access   (Followers: 1)
Ingeniería     Open Access  
Ingenieria de Recursos Naturales y del Ambiente     Open Access  
Ingeniería Energética     Open Access  
Ingenieria Industrial. Actualidad y Nuevas Tendencias     Open Access  
Ingeniería Investigación y Desarrollo     Open Access   (Followers: 2)
Ingeniería solidaria     Open Access   (Followers: 1)
Ingenieria y Ciencia     Open Access   (Followers: 1)
Ingeniería y Desarrollo     Open Access  
Ingenieria y Universidad     Open Access   (Followers: 1)
Ingeniería, Investigación y Tecnología     Open Access   (Followers: 1)
Ingenio Magno     Open Access  
Ingenius : Revista de Ciencia y Tecnología     Open Access  
Innovare : Revista de ciencia y tecnología     Open Access  
Instrumentation Science & Technology     Hybrid Journal   (Followers: 7)
Integration, the VLSI Journal     Hybrid Journal   (Followers: 5)
Intelligent Control and Automation     Open Access   (Followers: 6)
Intelligent Transportation Systems Magazine, IEEE     Full-text available via subscription   (Followers: 8)
Interface Science and Technology     Full-text available via subscription  
Intermetallics     Hybrid Journal   (Followers: 22)
International Archives of Science and Technology     Open Access  
International Communications in Heat and Mass Transfer     Hybrid Journal   (Followers: 20)
International conference KNOWLEDGE-BASED ORGANIZATION     Open Access  
International Heat Treatment and Surface Engineering     Hybrid Journal   (Followers: 5)
International Journal for Numerical Methods in Engineering     Hybrid Journal   (Followers: 29)
International Journal for Numerical Methods in Fluids     Hybrid Journal   (Followers: 19)
International Journal for Simulation and Multidisciplinary Design Optimization     Open Access   (Followers: 4)
International Journal for the History of Engineering & Technology     Hybrid Journal   (Followers: 8)
International Journal of Abrasive Technology     Hybrid Journal   (Followers: 2)
International Journal of Adaptive Control and Signal Processing     Hybrid Journal   (Followers: 2)
International Journal of Adhesion and Adhesives     Hybrid Journal   (Followers: 18)
International Journal of Advanced Engineering Research and Science IJAERS     Open Access   (Followers: 8)
International Journal of Advanced engineering, Management and Science     Open Access   (Followers: 1)
International Journal of Advancements in Technology     Open Access   (Followers: 1)
International Journal of Advances in Applied Sciences     Open Access   (Followers: 4)
International Journal of Advances in Engineering Sciences     Open Access   (Followers: 3)
International Journal of Advances in Engineering Sciences and Applied Mathematics     Hybrid Journal   (Followers: 1)
International Journal of Advances in Engineering, Science and Technology     Open Access   (Followers: 3)
International Journal of Aerodynamics     Hybrid Journal   (Followers: 20)
International Journal of Air-Conditioning and Refrigeration     Hybrid Journal   (Followers: 9)
International Journal of Antennas and Propagation     Open Access   (Followers: 11)
International Journal of Applied Ceramic Technology     Hybrid Journal   (Followers: 8)
International Journal of Applied Power Engineering     Open Access   (Followers: 4)
International Journal of Architectural Computing     Full-text available via subscription   (Followers: 5)
International Journal of Automation and Control Engineering     Open Access   (Followers: 4)
International Journal of Automotive Technology and Management     Hybrid Journal   (Followers: 6)
International Journal of Autonomic Computing     Hybrid Journal   (Followers: 1)
International Journal of Autonomous and Adaptive Communications Systems     Hybrid Journal   (Followers: 4)
International Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
International Journal of Bifurcation and Chaos     Hybrid Journal   (Followers: 2)
International Journal of Biomedical and Clinical Engineering     Full-text available via subscription   (Followers: 4)
International Journal of Biomedical Imaging     Open Access   (Followers: 5)
International Journal of Cast Metals Research     Hybrid Journal  
International Journal of Circuit Theory and Applications     Hybrid Journal   (Followers: 2)
International Journal of Coal Science & Technology     Open Access   (Followers: 1)
International Journal of Collaborative Engineering     Hybrid Journal  
International Journal of Communication Systems     Hybrid Journal   (Followers: 2)
International Journal of Complexity in Applied Science and Technology     Hybrid Journal  
International Journal of Computer Aided Engineering and Technology     Hybrid Journal   (Followers: 2)
International Journal of Computer Applications in Technology     Hybrid Journal   (Followers: 3)
International Journal of Control Science and Engineering     Open Access   (Followers: 5)
International Journal of Control, Automation and Systems     Hybrid Journal   (Followers: 12)
International Journal of Corrosion     Open Access   (Followers: 11)
International Journal of Crashworthiness     Hybrid Journal   (Followers: 9)
International Journal of Design Engineering     Hybrid Journal   (Followers: 14)
International Journal of Digital Multimedia Broadcasting     Open Access   (Followers: 5)
International Journal of Education and Management Engineering     Open Access   (Followers: 2)
International Journal of Education Economics and Development     Hybrid Journal   (Followers: 3)
International Journal of Embedded Systems     Hybrid Journal   (Followers: 5)
International Journal of Energy Optimization and Engineering     Hybrid Journal   (Followers: 5)
International Journal of Engine Research     Hybrid Journal   (Followers: 1)
International Journal of Engineering & Technology     Open Access   (Followers: 6)
International Journal of Engineering and Future Technology     Open Access  
International Journal of Engineering and Manufacturing     Open Access   (Followers: 1)
International Journal of Engineering and Technologies     Open Access   (Followers: 1)
International Journal of Engineering Business Management     Open Access   (Followers: 2)
International Journal of Engineering Education     Full-text available via subscription   (Followers: 6)
International Journal of Engineering Management and Economics     Hybrid Journal   (Followers: 4)
International Journal of Engineering Mathematics     Open Access   (Followers: 3)
International Journal of Engineering Pedagogy     Open Access  
International Journal of Engineering Practical Research     Open Access  
International Journal of Engineering Research in Africa     Full-text available via subscription   (Followers: 3)
International Journal of Engineering Science     Hybrid Journal   (Followers: 6)
International Journal of Engineering Systems Modelling and Simulation     Hybrid Journal   (Followers: 10)
International Journal of Engineering, Science and Technology     Open Access  
International Journal of Engineering, Social Justice, and Peace     Open Access   (Followers: 4)
International Journal of Environmental Engineering     Hybrid Journal   (Followers: 6)
International Journal of Experimental Design and Process Optimisation     Hybrid Journal   (Followers: 5)
International Journal of Fatigue     Hybrid Journal   (Followers: 34)
International Journal of Foresight and Innovation Policy     Hybrid Journal   (Followers: 6)
International Journal of Fracture     Hybrid Journal   (Followers: 12)
International Journal of Geo-Engineering     Open Access   (Followers: 2)
International Journal of Geotechnical Engineering     Hybrid Journal   (Followers: 6)
International Journal of Grid and Utility Computing     Hybrid Journal  
International Journal of Heat and Fluid Flow     Hybrid Journal   (Followers: 34)
International Journal of Heat and Mass Transfer     Hybrid Journal   (Followers: 181)
International Journal of Heavy Vehicle Systems     Hybrid Journal   (Followers: 6)
International Journal of Imaging Systems and Technology     Hybrid Journal   (Followers: 1)
International Journal of Impact Engineering     Hybrid Journal   (Followers: 9)
International Journal of Information Acquisition     Hybrid Journal   (Followers: 1)
International Journal of Innovation and Applied Studies     Open Access   (Followers: 5)
International Journal of Innovation Science     Hybrid Journal   (Followers: 9)
International Journal of Innovative Technology and Research     Open Access   (Followers: 2)
International Journal of Integrated Engineering     Open Access  
International Journal of Intelligent Engineering Informatics     Hybrid Journal  
International Journal of Intelligent Systems and Applications in Engineering     Open Access   (Followers: 3)
International Journal of Lifecycle Performance Engineering     Hybrid Journal   (Followers: 1)
International Journal of Machine Tools and Manufacture     Hybrid Journal   (Followers: 7)
International Journal of Manufacturing Research     Hybrid Journal   (Followers: 7)
International Journal of Manufacturing Technology and Management     Hybrid Journal   (Followers: 8)
International Journal of Marine Engineering Innovation and Research     Open Access  
International Journal of Materials and Product Technology     Hybrid Journal   (Followers: 4)
International Journal of Mathematical Education in Science and Technology     Hybrid Journal   (Followers: 9)
International Journal of Mathematics in Operational Research     Hybrid Journal  
International Journal of Medical Engineering and Informatics     Hybrid Journal   (Followers: 3)
International Journal of Micro Air Vehicles     Full-text available via subscription   (Followers: 8)
International Journal of Microwave Science and Technology     Open Access   (Followers: 3)
International Journal of Mobile Network Design and Innovation     Hybrid Journal   (Followers: 1)
International Journal of Multiphase Flow     Hybrid Journal   (Followers: 7)
International Journal of Nanomanufacturing     Hybrid Journal  
International Journal of Nanoscience     Hybrid Journal   (Followers: 1)
International Journal of Nanotechnology     Hybrid Journal   (Followers: 7)
International Journal of Nanotechnology and Molecular Computation     Full-text available via subscription   (Followers: 3)
International Journal of Navigation and Observation     Open Access   (Followers: 20)
International Journal of Network Management     Hybrid Journal   (Followers: 1)
International Journal of Nonlinear Dynamics and Control     Hybrid Journal  
International Journal of Nonlinear Sciences and Numerical Simulation     Hybrid Journal  
International Journal of Numerical Methods for Heat & Fluid Flow     Hybrid Journal   (Followers: 10)
International Journal of Optics     Open Access   (Followers: 7)
International Journal of Organisational Design and Engineering     Hybrid Journal   (Followers: 6)
International Journal of Pattern Recognition and Artificial Intelligence     Hybrid Journal   (Followers: 8)
International Journal of Pavement Engineering     Hybrid Journal   (Followers: 6)
International Journal of Physical Modelling in Geotechnics     Hybrid Journal   (Followers: 5)
International Journal of Plasticity     Hybrid Journal   (Followers: 7)
International Journal of Plastics Technology     Hybrid Journal   (Followers: 1)
International Journal of Polymer Analysis and Characterization     Hybrid Journal   (Followers: 7)
International Journal of Polymer Science     Open Access   (Followers: 23)
International Journal of Precision Engineering and Manufacturing     Hybrid Journal   (Followers: 8)
International Journal of Precision Engineering and Manufacturing-Green Technology     Hybrid Journal  
International Journal of Precision Technology     Hybrid Journal  
International Journal of Pressure Vessels and Piping     Hybrid Journal   (Followers: 19)
International Journal of Production Economics     Hybrid Journal   (Followers: 14)
International Journal of Quality and Innovation     Hybrid Journal   (Followers: 4)
International Journal of Quality Assurance in Engineering and Technology Education     Full-text available via subscription   (Followers: 3)
International Journal of Quality Engineering and Technology     Hybrid Journal   (Followers: 3)
International Journal of Quantum Information     Hybrid Journal   (Followers: 3)
International Journal of Rapid Manufacturing     Hybrid Journal   (Followers: 4)
International Journal of Recent Contributions from Engineering, Science & IT     Open Access   (Followers: 1)
International Journal of Reliability, Quality and Safety Engineering     Hybrid Journal   (Followers: 14)
International Journal of Renewable Energy Technology     Hybrid Journal   (Followers: 10)
International Journal of Robust and Nonlinear Control     Hybrid Journal   (Followers: 5)
International Journal of Science Engineering and Advance Technology     Open Access   (Followers: 1)
International Journal of Sediment Research     Full-text available via subscription   (Followers: 3)
International Journal of Self-Propagating High-Temperature Synthesis     Hybrid Journal   (Followers: 2)
International Journal of Service Science, Management, Engineering, and Technology     Full-text available via subscription   (Followers: 1)
International Journal of Signal and Imaging Systems Engineering     Hybrid Journal  
International Journal of Six Sigma and Competitive Advantage     Hybrid Journal   (Followers: 2)
International Journal of Social Robotics     Hybrid Journal   (Followers: 3)
International Journal of Software Engineering and Knowledge Engineering     Hybrid Journal   (Followers: 5)
International Journal of Space Science and Engineering     Hybrid Journal   (Followers: 8)
International Journal of Speech Technology     Hybrid Journal   (Followers: 8)
International Journal of Spray and Combustion Dynamics     Hybrid Journal   (Followers: 14)
International Journal of Surface Engineering and Interdisciplinary Materials Science     Full-text available via subscription   (Followers: 1)
International Journal of Surface Science and Engineering     Hybrid Journal   (Followers: 6)
International Journal of Sustainable Engineering     Hybrid Journal   (Followers: 7)
International Journal of Sustainable Manufacturing     Hybrid Journal   (Followers: 5)
International Journal of Systems and Service-Oriented Engineering     Full-text available via subscription  
International Journal of Systems Assurance Engineering and Management     Hybrid Journal  
International Journal of Systems, Control and Communications     Hybrid Journal   (Followers: 4)
International Journal of Technoethics     Full-text available via subscription   (Followers: 1)
International Journal of Technology Management and Sustainable Development     Hybrid Journal   (Followers: 1)
International Journal of Technology Policy and Law     Hybrid Journal   (Followers: 6)
International Journal of Telemedicine and Applications     Open Access   (Followers: 4)
International Journal of Thermal Sciences     Hybrid Journal   (Followers: 15)
International Journal of Thermodynamics     Open Access   (Followers: 8)
International Journal of Turbo & Jet-Engines     Hybrid Journal   (Followers: 4)
International Journal of Ultra Wideband Communications and Systems     Hybrid Journal  
International Journal of Vehicle Autonomous Systems     Hybrid Journal  
International Journal of Vehicle Design     Hybrid Journal   (Followers: 6)
International Journal of Vehicle Information and Communication Systems     Hybrid Journal   (Followers: 2)
International Journal of Vehicle Noise and Vibration     Hybrid Journal   (Followers: 4)
International Journal of Vehicle Safety     Hybrid Journal   (Followers: 6)
International Journal of Vehicular Technology     Open Access   (Followers: 4)

  First | 1 2 3 4 5 6 7 | Last

Journal Cover Engineering Analysis with Boundary Elements
  [SJR: 1.251]   [H-I: 52]   [1 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 0955-7997
   Published by Elsevier Homepage  [3043 journals]
  • Efficient analysis of plates on nonlinear foundations
    • Abstract: Publication date: October 2017
      Source:Engineering Analysis with Boundary Elements, Volume 83
      Author(s): Ahmed Fady Farid, Marina Reda, Youssef F. Rashed
      This paper presents efficient analysis of plates on nonlinear foundations. The Reissner plate theory is used to model plates. Foundations are presented as the Winkler springs or the elastic half space. The developed analysis is mainly presented for tensionless foundation; however as demonstrated, it is straightforward extended to analysis of elastic-plastic foundations. The plate is analyzed using the boundary element method (BEM). Unlike the traditional BEM which uses equations in form ([H] {u} = [G] {t}), the presented formulation uses finite element like equations, in the form of ([K] {u} = {P}). An innovative formulation is presented to derive the relevant plate stiffness matrix [K] and load vector {P} from the BEM integral equation. Iterative procedures together with condensation process are used to eliminate degree of freedom at failed zones. Results of the present analysis are more accurate than those obtained from previously published results. The main advantages of the presented technique are its simplicity and accuracy and it gains both advantages of the boundary element and the finite element methods.

      PubDate: 2017-07-27T17:23:35Z
       
  • A variational multiscale interpolating element-free Galerkin method for
           convection-diffusion and Stokes problems
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Tao Zhang, Xiaolin Li
      By combining the interpolating moving least squares (IMLS) method with the variational multiscale method, a variational multiscale interpolating element-free Galerkin (VMIEFG) method is presented in this paper for the numerical solutions of convection-diffusion and Stokes problems. In the VMIEFG, the IMLS is used to construct shape functions based on using shifted and scaled polynomial bases. Compared with the variational multiscale element-free Galerkin (VMEFG) method, the VMIEFG method can directly apply the essential boundary conditions. The VMIEFG method is an effective meshless method, especially, for convection-dominated problems. Numerical examples show that the VMIEFG method avoids the oscillation in the element-free Galerkin (EFG) method, and the computational precision of the VMIEFG method is higher than that of the EFG, the VMEFG and the finite element methods.

      PubDate: 2017-07-20T16:50:04Z
       
  • An implicit Method of Fundamental Solutions using twofold domains
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Csaba Gáspár
      A novel meshless method is presented. It is based on completing the original problem with an additional one which is defined in the same domain and connected with the original problem through the boundary only. The boundary conditions are enforced by some internal sources appearing in the supplementary problem only. The fundamental solutions are not used explicitly. The two problems are solved simultaneously using computationally quite efficient multi-level tools. No dense and ill-conditioned linear systems have to be solved. Moreover, no external or boundary sources are to be located. The approach can easily be extended to more general elliptic problems in a natural way, since the corresponding fundamental solution is not needed to be known.

      PubDate: 2017-07-20T16:50:04Z
       
  • Energy extraction of two flapping foils with tandem configurations and
           vortex interactions
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): G.D. Xu, W.H. Xu
      The energy extraction of two flapping foils with tandem configurations has been studied based on velocity potential theory. The interactions of the hind foil and the vortices of the fore foil with typical oscillatory motions are investigated. The global phase shift, which combines the longitudinal distance and the phase shift of the motions of the two foils, is introduced as the indicating parameter of the interaction modes. The effects of longitudinal distance and phase shift of the motions on the energy extraction efficiency have been analysed. The most favourable global phase shift and the corresponding vortex pattern have been investigated.

      PubDate: 2017-07-20T16:50:04Z
       
  • The weak coupling between MPS and BEM for wave structure interaction
           simulation
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Zhe Sun, K. Djidjeli, J.T. Xing
      As a Lagrangian type meshless method, the MPS is suitable for violent free surface problems. In this paper, for problems where violent free surface deformation only occur in a constrained area, the efficiency of MPS is further improved by weak coupling with BEM. More specifically, the whole computational domain is modeled by BEM whereas the MPS model only covers the violent flow area. Since the computational time of BEM is negligible compared with the time required by MPS, the overall computational efficiency could be improved by this coupling scheme (depends on how much of the MPS domain is replaced by BEM). The MPS model is advanced by the information from BEM result at each time step up to the time when the free surface is about to break. The MPS solver will continue the simulation with the “old” BEM information just before breaking, based on the assumption that the flow change at the MPS–BEM interface area is small enough. The proposed scheme is validated by two problems and a relatively good accuracy is obtained by comparing with published results in the literature.

      PubDate: 2017-07-08T02:29:46Z
       
  • Contour integral approaches for the evaluation of stress intensity factors
           using displacement discontinuity method
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Xin Cui, Hong Li, Guanwen Cheng, Chunan Tang, Xin Gao
      The stress intensity factors (SIFs) are of great importance for the determination of stress and displacement fields near crack tip and the prediction about crack propagations. In the context of linear elastic fracture mechanics (LEFM), this paper proposes contour integral approaches to calculate SIFs for two-dimensional cracks. The proposed approaches are derived from the conservative J- and I-integrals, in which constant elements of the displacement discontinuity method (DDM) are employed. Two numerical examples, a horizontal straight crack and a slanted straight crack under uniaxial tension at infinity, are conducted to demonstrate the validation of the approaches. Numerical results confirm that highly accurate SIFs can be extracted by integral contours remote from crack tip and increasing the total number of DDM elements can improve accuracy significantly.

      PubDate: 2017-07-08T02:29:46Z
       
  • Irregular wave transmission on bottom bumps using fully nonlinear NURBS
           numerical wave tank
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Arash Abbasnia, Mahmoud Ghiasi, Amir Hossein Abbasnia
      In this study, a fully nonlinear three-dimensional numerical wave tank (NWT) is developed to simulate propagation of nonlinear random sea wave over the bottom ripple patches. Evolution of the free surface is performed by the non-uniform rational B-spline formulation (NURBS) and the mixed Eulerian–Lagrangian method (MEL). A high-order boundary integral equation is used to solve the Laplace equation in the Eulerian frame. The free surface is updated by the material node method and the fourth-order Runge–Kutta time integration scheme. Appropriate numerical solutions are obtained by deploying damping zones at the both tank end walls. Also, the NURBS approximation is applied to compute the kinematics of the free surface particles. Propagation of the irregular waves in an NWT is conducted and compared with the available experimental and numerical data. Bragg reflection of the random sea wave due to bottom ripple patches are compared with the prior numerical studies. The fully nonlinear free surface evolution of transmitted spectrum due to presence of the hemispherical bumps is modeled successfully. Also fifth-order Stokes wave is applied as a strong nonlinear incident wave to interact with the hemispherical bottom bumps.

      PubDate: 2017-07-08T02:29:46Z
       
  • Numerical simulation of soil-structure elastodynamic interaction using
           iterative-adaptive BEM-FEM coupled strategies
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): L. Godinho, D. Soares
      The study of solid–solid interaction problems is of significant interest in many engineering areas, such as structural dynamics or soil–structure interaction problems. In many of these cases, a localized and well-defined structure is embedded or connected to an infinite or semi-infinite domain, and thus the best option is to use different numerical techniques to model each part of the problem. In this paper, the authors propose two iterative coupling strategies to tackle this type of problem, considering the structure to be modelled by the FEM and the soil by the BEM. In both approaches, optimized relaxation parameters are employed, improving the efficiency of the analyses. Within the proposed iterative coupling algorithms, adaptive refinement of the FEM mesh may also be performed, in order to increase the accuracy of the calculations. Numerical examples are presented in the end of the manuscript, illustrating the main features of the proposed methods, assessing their applicability and effectiveness.

      PubDate: 2017-07-08T02:29:46Z
       
  • A meshless generalized finite difference method for inverse Cauchy
           problems associated with three-dimensional inhomogeneous Helmholtz-type
           equations
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Qingsong Hua, Yan Gu, Wenzhen Qu, Wen Chen, Chuanzeng Zhang
      The generalized finite difference method (GFDM) is a relatively new domain-type meshless method for the numerical solution of certain boundary value problems. The method involves a coupling between the Taylor series expansions and weighted moving least-squares method. The main idea here is to fully inherit the high-accuracy advantage of the former and the stability and meshless attributes of the latter. This paper makes the first attempt to apply the method for the numerical solution of inverse Cauchy problems associated with three-dimensional (3D) Helmholtz-type equations. Numerical results for three benchmark examples involving Helmholtz and modified Helmholtz equations in both smooth and piecewise smooth 3D geometries have been analyzed. The convergence, accuracy and stability of the method with respect to increasing the number of scatted nodes inside the whole domain and decreasing the amount of noise added into the input data, respectively, have been well-studied.

      PubDate: 2017-07-08T02:29:46Z
       
  • Meshfree radial point interpolation method for analysis of viscoplastic
           problems
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Z. Kazemi, M.R. Hematiyan, R. Vaghefi
      A truly meshfree radial point interpolation method (RPIM) for analysis of viscoplastic problems is presented. Without recourse to any background cell, a fast and accurate meshfree integration method is employed for computation of the domain integrals in the RPIM. The effects of the total number of nodes and the parameters of the meshfree method on the accuracy of the solutions are studied too. Moreover, the effects of the viscoplastic material parameters on the results are investigated. To demonstrate the accuracy of the proposed method and provide a comprehensive investigation of the viscoplastic and meshfree parameters, several numerical examples are presented. Excellent agreements are observed through comparing the obtained results with those retrieved by the finite element method.

      PubDate: 2017-07-08T02:29:46Z
       
  • The extended method of approximate particular solutions to simulate
           two-dimensional electromagnetic scattering from arbitrary shaped
           anisotropic objects
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Maryam Hajisadeghi Esfahani, Hadi Roohani Ghehsareh, Seyed Kamal Etesami
      The numerical simulation of electromagnetic scattering problem by cylinders of arbitrary cross-section made of homogeneous and anisotropic material is carried out. The anisotropic materials are characterized by symmetric and positive definite magnetic permeability tensors. An efficient and powerful meshfree strong form technique based on the particular solutions of anisotropic radial basis functions (A-RBFs) is extended to deal with anisotropic problem directly. The A-RBFs are constructed by introducing a special norm associated to the appearing anisotropic tensor and replacing it with the standard Euclidean norm in RBFs. The particular solutions for the anisotropic Laplace operator are approximated explicitly by using the anisotropic radial basis functions. Because of material discontinuity at the interface of anisotropic and free regions, two different sets of basis functions, the approximate particular solutions of the anisotropic generalized multiquadric (A-GMQ) and the standard generalized multiquadric (GMQ) functions are employed to approximate the total electric field inside and the scattered field outside the anisotropic scatterer respectively. Some numerical simulations are implemented to confirm the accuracy and efficiency of the method for anisotropic scatterer with arbitrary cross-sections.

      PubDate: 2017-06-27T02:09:10Z
       
  • Asymmetric rheological behaviors of double-emulsion globules with
           asymmetric internal structures in modest extensional flows
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Genmiao Xu, Xiaoyong Wang, Shen Xu, Jingtao Wang
      The oriented shift and inverse of double-emulsion globules containing two inner droplets with different sizes and locations in modest extensional flows are investigated numerically in this paper through a boundary element method. The asymmetric layout of daughter droplets leads to the asymmetric inner flow field and pressure field inside the globule, which causes its asymmetric rheological behaviors. The direction of shift is determined not only by the size ratio rR 2/rL 2 and the location ratio dR/dL of two inner droplets, but also by some flow factors such as the capillary number Ca. There is a critical capillary number Cac as a function of rR 2/rL 2 and dR/dL, beyond which the globule will move to the right, otherwise, it will shift to the opposite direction.

      PubDate: 2017-06-27T02:09:10Z
       
  • A boundary element method recursive procedure applied to Poisson's
           problems
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): V.E.S. Ramos, C.F. Loeffler, W.J. Mansur
      This paper describes a simple procedure to increase the accuracy of the boundary element method (BEM) results in Poisson's problems using coarse meshes. Usually, BEM values at internal points are obtained by reusing the boundary integral equation, after having calculated all variables at the nodal points on the boundary. Accuracy in results of these internal points is superior to that obtained at boundary nodes and the reason for that can be assigned to a new minimization of residuals performed. Therefore, this idea can be used to improve BEM results by means of choosing new source points on the boundary at positions different from those of the original nodes. Tests carried out with problems governed by Laplace's equation and Navier's equation were successful; thus, this procedure is now applied to Poisson's problems that allow a more comprehensive evaluation of the performance of proposed technique.

      PubDate: 2017-06-27T02:09:10Z
       
  • On the removal of rigid body motions in the interior BVP of plane
           elasticity by using node support in conjunction with least square
           technique
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Y.Z. Chen
      This paper provides an effective technique for removing the rigid body motions in the interior traction BVP (boundary value problem) of plane elasticity. In the technique, we assume three additional node support conditions. After substituting those conditions in the algebraic equations derived from discretization of BIE (boundary integral equation), we will obtain the algebraic equations where the number of the equations is larger than the number of unknowns. The mentioned algebraic equations can be solved by using the least square technique. Finally, the displacement vector can be evaluated. A stress component derived from the suggested technique is compared to the exact one. Excellent accuracy has been found in the suggested technique.

      PubDate: 2017-06-19T18:09:32Z
       
  • Finite integration method with radial basis function for solving stiff
           problems
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Y. Li, Y.C. Hon
      We combine in this paper the recently developed finite integration method (FIM) with radial basis function (FIM–RBF) to solve stiff problems. The idea of FIM is to transform partial differential equations (PDEs) into integral equations whose approximations can be stably and accurately obtained from standard numerical quadratures. This contributes to one distinct benefit: smoothing out the instability of solution process in solving stiff problems modelled by PDEs. The other distinct benefit comes from the truly meshfree advantage of radial basis function (RBF) method for solving various kinds of well-posed PDEs with superior accuracy. Since the RBF method gives an intrinsic full, and hence ill-conditioned, resultant matrix, it fails to tackle stiff problems. The combination of FIM and RBF method enjoys not only the distinct benefit of smoothing out stiffness but also gives a much less ill-conditioned resultant matrix. As a result, the headache problem on choosing critical value of shape parameter for spectral convergence in RBF does not persist. Numerical results indicated that the accuracy of the FIM–RBF has been increased by approximately two order of magnitude with only one third of CPU time in comparing to some other spectral methods such as wavelet adaptive scheme.

      PubDate: 2017-06-14T17:57:16Z
       
  • A combination of isogeometric technique and scaled boundary method for the
           solution of the steady-state heat transfer problems in arbitrary plane
           domain with Robin boundary
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Peng Li, Jun Liu, Gao Lin, Pengchong Zhang, Bin Xu
      The scaled boundary finite element method (SBFEM) has attracted considerable attention in recent years as a novel semi-analytical computational approach since only the boundary is discretized using finite element approach and the spatial dimension is reduced by one in this method. By introducing the radial and circumferential scaled boundary coordinates in this method, the reduction of spatial dimension is accomplished by using the conventional Lagrange functions to weaken the governing equations in the circumferential direction, while to work analytically in the radial direction. The NURBS-based isogeometric analysis (IGA) has remarkable advantages due to its integration of CAD/CAE, geometrical exact discretization for free-form shapes and numerical accuracy. Thus, an isogeometric analysis based on the framework of scaled boundary method (IGA-SBM) is proposed, which combines the concepts of IGA and SBFEM by employing NURBS to represent the unknown field variables in the circumferential direction. In this work, the IGA-SBM is extended to the solutions of the steady-state heat transfer problems in arbitrary plane domain enclosed by the complex boundary geometry. Four numerical examples are presented to illustrate that the excellent accuracy, computational efficiency and convergence performance of IGA-SBM. The numerical studies show that the heat transfer problems with complicated configuration can be more effectively handled by considering the combination of IGA and SBFEM.

      PubDate: 2017-06-14T17:57:16Z
       
  • Finite block method in fracture analysis with functionally graded
           materials
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): J. Li, J.Z. Liu, T. Korakianitis, P.H. Wen
      The finite block method (FBM) is developed to determine stress intensity factors with orthotropic functionally graded materials under static and dynamic loads in this paper. By employing the Lagrange series, the first order partial differential matrix for one block is derived with arbitrary distribution of nodes. The higher order derivative matrix for two dimensional problems can be constructed directly. For linear elastic fracture mechanics, the COD and J-integral techniques to determine the stress intensity factors are formulated. For the dynamic problems, the Laplace transform method and Durbin's inverse technique are employed. Several examples are given and comparisons have been made with both the finite element method and analytical solutions in order to demonstrate the accuracy and convergence of the finite block method.

      PubDate: 2017-06-14T17:57:16Z
       
  • A numerical mesh-free model for elasto-plastic contact problems
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Youssef Belaasilia, Abdelaziz Timesli, Bouazza Braikat, Mohammad Jamal
      A numerical mesh-free model applied to a strong formulation for simulating elasto-plastic structures with contact is developed in the context of large deformation. This numerical mesh-free model is based on the Asymptotic Numerical Method (ANM) which is used in the meshless collocation framework to extend its application field to elasto-plastic problems with contact. The efficiency of this model is to take into account of large deformations and to avoid the meshing distortion problem. According to (ANM) techniques, the development in Taylor series is performed to obtain a sequence of linear systems to be solved. These linear systems are then discretized by a collocation meshless approach by using the Moving Least Squares (MLS) functions and a continuation method is adopted to evaluate the solution. The unilateral contact problem is identified to boundary conditions which are replaced by force-displacement relations through a regularization technique. The performance of the proposed approach is tested on several elasto-plastic bi-dimensional examples without and with contact. The obtained results are compared to those computed by the Newton–Raphson method.

      PubDate: 2017-06-14T17:57:16Z
       
  • Horn effect prediction based on the time domain boundary element method
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Yang Zhang, Chuan-Xing Bi, Yong-Bin Zhang, Xiao-Zheng Zhang
      A time domain boundary element method (TBEM) is applied to predict the horn effect. As the time response calculated by the time domain boundary integral equation contains the resonance components, when transformed to the frequency domain, the result will corrupt at the characteristic frequencies. To overcome this problem, a Burton–Miller-type combined time domain integral equation in half-space is applied. The resonance components are excluded in the time domain calculation, thus the corruptions are avoided in the frequency domain. As a result, the horn effect can be predicted very well at all frequencies. Compared to the frequency domain boundary element method for predicting the horn effect, the TBEM is more efficient due to the lower cost of forming coefficient matrices and solving equations. A numerical simulation is carried out to demonstrate the efficiency of the TBEM, and two experiments are conducted to validate the proposed method in predicting the horn effect. Both numerical and experimental results indicate that the proposed method is reliable and efficient in predicting the horn effect.

      PubDate: 2017-06-14T17:57:16Z
       
  • A two-dimensional consistent approach for static and dynamic analyses of
           uniform beams
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): Jianghuai Li, Zhiyu Shi, Shaowu Ning
      A unified technique based on the scaled boundary finite element method is presented in this paper to analyze the bending, free vibration and forced vibration of thin to moderately thick beams with constant material properties and rectangular cross sections. The structure model is treated as a plane stress problem and the principle of virtual work involving the inertial force is applied to derive the scaled boundary finite element equation. Higher order spectral elements are used to discretize the longitudinal dimension and the solution through the thickness is expressed analytically as a Padé expansion. A variable transformation technique facilitates the development of the dynamic stiffness matrix, which leads to the static stiffness and mass matrices naturally. Rayleigh damping and Newmark-β method are employed to perform the forced vibration analysis. Numerical examples covering static and dynamic analyses validate the excellent performance and capability of this approach.

      PubDate: 2017-06-09T17:29:40Z
       
  • Acceleration of a BEM based solution of the velocity–vorticity
           formulation of the Navier–Stokes equations by the cross approximation
           method
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): J. Tibaut, L. Škerget, J. Ravnik
      In this paper, we present a method to decrease the computational demand of the boundary-domain integral equation based 3D flow solver. We focus on the solution of the velocity–vorticity formulation of the Navier–Stokes equation, which governs incompressible viscous fluid flow. We introduce the cross approximation into the solution of the boundary vorticity values. This problem is governed by the Poisson type kinematics equation and presents a computational bottleneck of the algorithm. In order to accelerate the flow solver, we approximate the domain contribution of the kinematics integral equation by the cross approximation algorithm. The cross approximation method is used in combination with the hierarchical decomposition of the domain boundary combined by the hierarchical decomposition of domain interior. We propose to specify the approximation extent by controlling the depth of the hierarchical decomposition and the rank of the approximated integral matrix parts. The developed algorithm is tested using the Arnold–Beltrami–Childress and lid driven cavity flows. We study the accuracy of boundary vorticity estimation and of the flow solution for different flow complexities (Reynolds number values), computational mesh densities and cross approximation settings. We found that that by using the cross approximation technique in the flow solver, we were able to reduce the computational demands of storing matrices to approximately 30% of the storage space of the original matrices. Furthermore, we showed that achieved approximation extent depends on the complexity of the simulated flow problem.

      PubDate: 2017-06-09T17:29:40Z
       
  • Direct time domain evaluation of the transient field transmitted into a
           lossy ground due to GPR antenna radiation
    • Abstract: Publication date: September 2017
      Source:Engineering Analysis with Boundary Elements, Volume 82
      Author(s): D. Poljak, S. Sesnic, A. Susnjara, D. Paric, K. El Khamlichi Drissi, S. Lallechere
      The paper deals with the direct time domain calculation of a transient electric field generated by a ground penetrating radar (GPR) dipole antenna and transmitted into the lossy half-space. The space–time dependent current along the dipole is governed by the Hallen integral equation which is numerically solved by means of the Galerkin–Bubnov scheme of the Indirect Boundary Element Method (GB-IBEM). Provided that the current distribution along the GPR antenna is determined, one may compute the related electromagnetic field transmitted into the lossy ground by solving the field integral formulas. Some illustrative computational examples related to the transmitted field into the lower half-space are reported in this paper.

      PubDate: 2017-06-09T17:29:40Z
       
  • Modeling elastic wave propagation in fluid-filled boreholes drilled in
           nonhomogeneous media: BEM-MLPG versus BEM-FEM coupling
    • Abstract: Publication date: August 2017
      Source:Engineering Analysis with Boundary Elements, Volume 81
      Author(s): A. Tadeu, A. Romero, P. Stanak, J. Sladek, V. Sladek, P. Galvín, J. Antonio
      The efficiency of two coupling formulations, the boundary element method (BEM)-meshless local Petrov–Galerkin (MLPG) versus the BEM-finite element method (FEM), used to simulate the elastic wave propagation in fluid-filled boreholes generated by a blast load, is compared. The longitudinal geometry is assumed to be invariant in the axial direction (2.5D formulation). The material properties in the vicinity of the borehole are assumed to be nonhomogeneous as a result of the construction process and the ageing of the material. In both models, the BEM is used to tackle the propagation within the fluid domain inside the borehole and the unbounded homogeneous domain. The MLPG and the FEM are used to simulate the confined, damaged, nonhomogeneous, surrounding borehole, thus utilizing the advantages of these methods in modeling nonhomogeneous bounded media. In both numerical techniques the coupling is accomplished directly at the nodal points located at the common interfaces. Continuity of stresses and displacements is imposed at the solid–solid interface, while continuity of normal stresses and displacements and null shear stress are prescribed at the fluid–solid interface. The performance of each coupled BEM-MLPG and BEM-FEM approach is determined using referenced results provided by an analytical solution developed for a circular multi-layered subdomain. The comparison of the coupled techniques is evaluated for different excitation frequencies, axial wavenumbers and degrees of freedom (nodal points).

      PubDate: 2017-06-05T17:18:48Z
       
  • A BEM/FEM formulation for the analysis of piles submitted to horizontal
           loads
    • Abstract: Publication date: August 2017
      Source:Engineering Analysis with Boundary Elements, Volume 81
      Author(s): Endi Samba Luamba, João Batista de Paiva
      In this paper a coupled Boundary Element Method (BEM)/Finite Element Method (FEM) formulation for the analysis of pile–soil interaction problems with the pile submitted to horizontal loading is presented. The soil is supposed to be a semi-infinite elastic, isotropic continuum and is modeled by the BEM and the piles are modeled by the finite element method. In the final system of equations the unknowns’ vector are the displacements and rotations at the nodes of the pile which, unlike other formulations, allows coupling with a foundation plate and a pile cap. Examples of single piles subjected to horizontal loading are analyzed with the presented formulation and their results compared with those from other formulations.

      PubDate: 2017-06-05T17:18:48Z
       
  • Effects of sudden change in pitch angle on oscillating wind turbine
           airfoil performances
    • Abstract: Publication date: August 2017
      Source:Engineering Analysis with Boundary Elements, Volume 81
      Author(s): M.M. Oueslati, A.W. Dahmouni, S. Ben Nasrallah
      In this paper, the aerodynamic performances of a wind turbine airfoil in sinusoidal pitching motion was numerically predicted and analyzed using the two-dimensional singularity method. A parametric study based on the sudden pitch angle rate variation, the reduced frequency and the pitching amplitudes have been investigated. The results highlight the sudden change effect in pitch angle on the aerodynamic performances of the airfoil and the shedding wake. The aspect of lift and drag coefficient loops and hysteresis were customized regarding to the pure sinusoidal motion case. The dynamic stall phenomenon, which occurs during the rapid change in pitch angle, produces more drag forces influencing the wind turbines performance.

      PubDate: 2017-06-05T17:18:48Z
       
  • A continuous–discontinuous hybrid boundary node method for solving
           stress intensity factor
    • Abstract: Publication date: August 2017
      Source:Engineering Analysis with Boundary Elements, Volume 81
      Author(s): Fei Yan, Xia-Ting Feng, Jia-He Lv, Shao-Jun Li
      A novel boundary type meshless method called continuous–discontinuous hybrid boundary node method is proposed in this paper, in which the enriched discontinuous shape function is developed to solve linear elastic crack problems. Firstly, the whole boundary is divided into several individual segments, and variables on each one of those segments are interpolated, respectively. For continuous segments, radial point interpolation method is employed. In regard to discontinuous segments, the enriched discontinuous basis functions combining with radial point interpolation method are developed for simulating the discontinuity of displacement and stress field on surfaces of crack, and the near tip asymptotic field functions are employed for simulating the high gradient of stress field around crack tip, so that high accuracy and discontinuity property of a crack can be easily described. Stress intensity factors are calculated directly using displacement extrapolation by displacement field near crack tip. Some numerical examples are shown that the present method is effective and can be widely applied in some practical engineering.

      PubDate: 2017-06-05T17:18:48Z
       
  • Boundary element method simulation of 3D heat diffusion in defective
           layered media for IRT building applications
    • Abstract: Publication date: August 2017
      Source:Engineering Analysis with Boundary Elements, Volume 81
      Author(s): C. Serra, A. Tadeu, N. Simões
      This paper presents a numerical model to simulate heat transfer by conduction in defective layered media, looking to contribute to the interpretation of thermographic results obtained in active Infrared Thermography (IRT) tests performed on building elements. The proposed model is developed to simulate 3D heat diffusion in a multilayered system containing a 3D thin defect (considered to be a null thickness inclusion). The proposed model uses the frequency domain Boundary Element Method (BEM) formulation written in terms of normal derivative integral equation formulation, referred to here as TBEM, in order to handle the null thickness of the defect. 3D Green's functions for multilayered media are used to avoid the discretization of the interfaces between layers. These 3D Green's functions are expressed as Bessel integrals and written as the sum of source terms and terms which are defined by imposing the required boundary conditions at each interface. When using this procedure, only the defect's surface is discretized. The proposed solution is verified against a previously developed 3D TBEM formulation for unbounded media using a mirror image source technique. To illustrate the applicability of the proposed methodology in active IRT, time-domain and phase contrast results are simulated and presented.

      PubDate: 2017-06-05T17:18:48Z
       
  • A scaled boundary finite element formulation over arbitrary faceted star
           convex polyhedra
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Sundararajan Natarajan, Ean Tat Ooi, Albert Saputra, Chongmin Song
      In this paper, a displacement based finite element framework for general three-dimensional convex polyhedra is presented. The method is based on a semi-analytical framework, the scaled boundary finite element method. The method relies on the definition of a scaling center from which the entire boundary is visible. The salient feature of the method is that the discretizations are restricted to the surfaces of the polyhedron, thus reducing the dimensionality of the problem by one. Hence, an explicit form of the shape functions inside the polyhedron is not required. Conforming shape functions defined over arbitrary polygon, such as the Wachpress interpolants are used over each surface of the polyhedron. Analytical integration is employed within the polyhedron. The proposed method passes patch test to machine precision. The convergence and the accuracy properties of the method is discussed by solving few benchmark problems in linear elasticity.

      PubDate: 2017-05-20T15:20:49Z
       
  • Dual reciprocity boundary node method for convection-diffusion problems
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Fei Yan, Min Yu, Jia-He Lv
      This paper presents a dual reciprocity boundary node method(DHBNM) for steady-state convection-diffusion problems with variable velocities. In this formulation, the solutions are composed of a particular and a complementary solutions, where the former is solved by boundary node method, and the latter is obtained by dual reciprocity method(DRM). The velocity field is decomposed into an average and a perturbation ones, which is treated using DRM by some steps of approximating process. A reverse procedure for the particular solution is developed to overcome the difficulty of getting the analytical solution of the particular solution. Numerical studies have validated that the DHBNM can produce high accuracy and stability.

      PubDate: 2017-05-20T15:20:49Z
       
  • Numerical solution of EFIE using MLPG methods
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Babak Honarbakhsh
      Meshless local Petrov-Galerkin (MLPG) methods are applied to the electric-field integral equation (EFIE), including seven previously reported schemes and two new suggested. The required dyadic weightings are provided. Especially, the dyadic Green’s function for the differential part of the equation is derived for the first time. Guidelines are suggested for both meshless discretization and efficient implementation. It is shown that by proper selection of the MLPG scheme and its parameters, the stiffness matrix corresponding to the problem can be computed using closed-form expressions, without the need to perform numerical integration. It is shown that using weightings other than the Dirac delta can significantly improve the convergence trend of the meshless solution and increase the accuracy up to two orders of magnitude. It is, also, demonstrated that a meshfree IE solver can more accurately track singularities of the surface current density at conductive edges compared to the method of moments (MoM). In addition, it is shown that such solvers can potentially supersede high-order (HO) MoM as their mesh-based counterpart.

      PubDate: 2017-05-15T14:37:25Z
       
  • Dynamic simulation of landslide dam behavior considering kinematic
           characteristics using a coupled DDA-SPH method
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Wei Wang, Guangqi Chen, Yingbin Zhang, Lu Zheng, Hong Zhang
      Landslide with significant volume and considerable velocity may block the river stream in the hillslope-channel coupling system, forming the natural dam and the dammed-lake behind. Previous studies predicted the behavior of landslide dams using different dimensionless indexes derived from the geomorphological characteristics. However, the kinematic characteristics of the river and landslide also play key roles in the dam formation. To consider the kinematic characteristics, the dynamic simulation of the dam behavior (formation and failure) involves three problems: (i) the movement of the river flow, (ii) the landslide movement and (iii) the landslide-river interaction. In this study, the movement of the river flow is simulated by a particle recycling method (PRM) under the framework of smoothed particle hydrodynamics (SPH). The discontinuous deformation analysis (DDA) is used to model the landslide movement. The interaction between the solid and fluid phases is achieved by the coupled DDA-SPH method. The proposed methods have been implemented in the numerical code, and a series of examples were employed for validations. The importance of the kinematic characteristics for the dam behavior was demonstrated by a series of numerical scenarios.

      PubDate: 2017-05-10T14:04:37Z
       
  • A family of exponentially-gradient elements for numerical computation of
           singular boundary value problems
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Morteza Eskandari-Ghadi, Delaram Mehdizadeh, Ali Morshedifard, Mohammad Rahimian
      In this paper, a new family of single-parameter exponentially gradient elements (EG-elements) are introduced, which can be used in various numerical procedures such as boundary and finite element methods. These elements have the ability to accurately interpolate the unknown values in regions, where either high gradient or singularity of the unknown field occurs. The shape functions of two-dimensional EG-elements are high gradient at either a corner of the element or at an edge of the element. Another advantage of this element is that the regular quadratic shape functions are obtained as a special case of EG-elements by adjusting the single parameter of the element, which allows this element to be used as regular Lagrange quadratic element, where it is appropriate. Some mixed boundary value problems are solved with the use of EG-elements in a boundary element program to show the capability of these elements for capturing the solution with less number of elements and higher accuracy.

      PubDate: 2017-05-10T14:04:37Z
       
  • Creep crack analysis of viscoelastic material by numerical manifold method
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Jun He, Quansheng Liu, Zhijun Wu
      In order to gain an insight into creep induced cracking in viscoelastic materials, the creep crack phenomenon in viscoelastic materials are numerically investigated in this paper based on the numerical manifold method (NMM). To more realistically capture the mechanical behaviour in the vicinity of crack tips, the local displacements around crack tips are enriched with the viscoelastic crack-tip asymptotic displacement field. To better represent the viscoelastic materials, an incremental viscoelastic constitutive law based on the generalized Kelvin-Voigt model is incorporated into the NMM. To achieve these treatments in the NMM, an incremental viscoelastic NMM formulation is derived. In addition, an incremental formulation of the mixed mode viscoelastic energy release rate (ERR), which can be tackled in the same process with the incremental viscoelastic constitutive law, is derived and incorporated into the NMM for investigating the variations of the ERR in viscoelastic materials. Based on the developed method, three creep crack problems with different loading conditions and pre-existing crack configurations are simulated, and the crack opening and sliding displacements as well as corresponding mixed mode ERR are analysed. Simulation results show good agreement with the theoretical solutions, which indicate that the proposed NMM is suitable for complex creep crack problems.

      PubDate: 2017-05-06T13:52:48Z
       
  • The MFS and MAFS for solving Laplace and biharmonic equations
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Xiangnan Pei, C.S. Chen, Fangfang Dou
      The method of fundamental solutions (MFS) has been known as an effective boundary meshless method for solving homogeneous differential equations with smooth boundary conditions and boundary shapes. Despite many attractive features of the MFS, the determination of the source location and the boundaries with sharp corners still pose a certain degree of challenges. In this paper, we revisit another powerful boundary method, the method of approximate fundamental solutions (MAFS), which approximates the fundamental solution using trigonometric functions. In the MAFS, the fundamental solutions for various governed equations can be easily constructed. The placement of the source points is also simple. In this paper, we will apply the MAFS for solving the Laplace equation with non-harmonic boundary conditions and the biharmonic equation with non-biharmonic boundary conditions with highly irregular or non-smooth domains. We will compare the performance of the MAFS and the MFS in these types of problems.

      PubDate: 2017-05-06T13:52:48Z
       
  • A new method for essential boundary conditions imposition in explicit
           meshless methods
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Grand Roman Joldes, Habib Chowdhury, Adam Wittek, Karol Miller
      In this paper we present a new technique of enforcing Essential Boundary Conditions (EBC) in Meshless Methods (MMs) based on the Element Free Galerkin (EFG) principles. Imposing EBC is a fundamental issue in MMs. The imposition of prescribed displacement values on the boundary in MMs based on approximating shape functions is not as straightforward as in the Finite Element Method (FEM) because the meshless shape functions are generally not interpolating at nodes. Furthermore, many techniques of enforcing EBC are not compatible with explicit time integration schemes. This paper describes a new method of imposing EBC in EFG based MMs suitable for explicit time integration, named Essential Boundary Conditions Imposition in Explicit Meshless (EBCIEM). The effectiveness of the proposed method is demonstrated using both 2D and 3D numerical examples.

      PubDate: 2017-05-06T13:52:48Z
       
  • Evaluation of the degenerate scale in Laplace equation by using Newton
           iteration method
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Y.Z. Chen
      This paper provides a numerical solution for the degenerate scale in antiplane elasticity or Laplace equation by using the null field boundary integral equation (BIE). When the used scale coincides with the degenerate scale, the relevant influence matrix is singular. The determinant of the influence matrix is expressed by a function of scale. Therefore, the problem for finding the degenerate scale can be reduced to a problem for finding the zeros of the function. Newton iteration method is used to find the zeros. Three numerical examples are provided in the paper.

      PubDate: 2017-05-06T13:52:48Z
       
  • An ACA accelerated isogeometric boundary element analysis of potential
           problems with non-uniform boundary conditions
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Lucas Silveira Campos, Éder Lima de Albuquerque, Luiz Carlos Wrobel
      This paper presents an Adaptive Cross Approximation (ACA) accelerated Isogeometric Boundary Element Method (IGBEM) using Non-Uniform Rational B-Splines (NURBS) as shape and interpolation functions. Provided that NURBS are used in CAD programs to describe geometry, mesh generation in the IGBEM is no longer necessary. For large and complex models the traditional BEM quickly becomes very time and memory consuming. In order to overcome this problem, the use of ACA is considered in this paper. As the NURBS control points are typically located outside the boundary, non-uniform boundary conditions cannot be applied at control points. So, a transformation matrix is used to allow the application of boundary conditions at control points without losing accuracy and, with a special approach, preserving the time and memory advantages of hierarchical matrices provided by the ACA. Two and tree dimensional numerical examples are presented in order to assess the accuracy and feasibility of the method.

      PubDate: 2017-05-06T13:52:48Z
       
  • A stochastic perturbation edge-based smoothed finite element method for
           the analysis of uncertain structural-acoustics problems with random
           variables
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): F. Wu, L.Y. Yao, M. Hu, Z.C. He
      Among the current methods in predicting the response of structural-acoustics problems in mid-frequency regime, some problems such as low accuracy and inability to deal with the uncertainties still need to be solved. To eliminate these issues, a novel stochastic perturbation edge-based smoothed FEM method (SP-ES-FEM) is proposed for the analysis of structural-acoustics problems in this work. The edge-based smoothing technique is applied in the standard FEM approach to soften the over-stiff behavior of structural-acoustics problems aiming to improve the accuracy of deterministic response predictions. Then, this approach, for the first time, intends to introduce the first-order perturbation technique into the edge-based smoothed FEM theory frame especially for the probabilistic analysis of structural-acoustics problems. The response of the coupled systems can be expressed simply as a linear function of all the pre-defined input variables by using the change of variable techniques. Due to the linear relationships of variables and response, the probability density function and cumulative probability density function of the response can be obtained based on the simple mathematical transformation of probability theory. The proposed approach not only improves the numerical accuracy of deterministic output quantities with respect to a given random variable, but also can handle the randomness well in the systems. Two numerical examples for frequency response analysis of random structural-acoustics are presented and verified by Monte Carlo simulation, to demonstrate the effectiveness of the present method.

      PubDate: 2017-05-06T13:52:48Z
       
  • The Strong Discontinuity Approach as a limit case of strain localization
           in the implicit BEM formulation
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): R.G. Peixoto, G.O. Ribeiro, R.L.S. Pitangueira, S.S. Penna
      The Implicit Formulation of the Boundary Element Method (BEM) is used to deal with physically non-linear 2D-problems in solids. An isotropic damage constitutive model, equipped with a strain softening rule, is applied to increasingly narrow bandwidths, determined by mesh refinement, showing the typical post-peak mesh-dependence behaviour. The Continuum Strong Discontinuity Approach (CSDA), characterized by the introduction of discontinuous jumps in the displacement field together with an equilibrium verification (using continuous constitutive models) on the discontinuity line, is also applied to the implicit formulation of the BEM. By a simple numerical example, it is shown that, beyond the mesh independence, the CSDA results represent the limit case of a zero localization bandwidth. Moreover, to demonstrate the accuracy of the CSDA, other three examples involving concrete fracture are presented and the obtained results are compared with experimental or analytical data available in the literature.

      PubDate: 2017-05-06T13:52:48Z
       
  • The stable node-based smoothed finite element method for analyzing
           acoustic radiation problems
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Xin Hu, Xiangyang Cui, Qunyi Zhang, Gang Wang, Guangyao Li
      In this paper, the stable node-based smoothed finite element method (SNS-FEM) and the well-known Dirichlet-to-Neumann (DtN) boundary condition are coupled together to reduce the dispersion error in analyzing acoustic radiation problems. An artificial boundary is introduced to truncate the infinite domain and the DtN boundary condition is imposed on the artificial boundary to guarantee the uniqueness of the solution. In the SNS-FEM formulation, a stable item which contains the gradient variance items is constructed without any uncertain parameter to strengthen the system stiffness. Through this operation, a perfect balance between the stiffness and mass matrices is established and the dispersion error is reduced significantly. Two benchmark cases and two practical engineering problems are employed to investigate the performance of the SNS-FEM. The results demonstrate that the SNS-FEM achieves super accuracy and super convergence. Additionally, the SNS-FEM is less sensitive to the wave number and high-efficiency.

      PubDate: 2017-05-06T13:52:48Z
       
  • A boundary element and level set based bi-directional evolutionary
           structural optimisation with a volume constraint
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Baseer Ullah, Jon Trevelyan, Siraj-ul-Islam
      A new topology optimisation algorithm is implemented and presented for compliance minimisation of continuum structures using a volume preserving mechanism which effectively handles a volume constraint. The volume preserving mechanism is based on a unique combination of the level set method and a boundary element based bi-directional evolutionary structural optimisation approach using a bisectioning algorithm. The evolving structural geometry is implicitly represented with the level sets, efficiently handling complex topological shape changes, including holes merging with each other and with the boundary. Numerical results for two-dimensional linear elasticity problems suggest that the proposed adaptation provides smooth convergence of the objective function and a more robust, smoother geometrical description of the optimal design. Moreover, this new implementation allows for efficient material re-distribution within the design domain such that the objective function is minimised at constant volume. The proposed volume preserving mechanism can be easily extended to three-dimensional space.

      PubDate: 2017-05-06T13:52:48Z
       
  • An improved radial basis-pseudospectral method with hybrid Gaussian-cubic
           kernels
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Pankaj K. Mishra, Sankar K. Nath, Gregor Kosec, Mrinal K. Sen
      While pseudospectral (PS) methods can feature very high accuracy, they tend to be severely limited in terms of geometric flexibility. Application of global radial basis functions overcomes this, however at the expense of problematic conditioning (1) in their most accurate flat basis function regime, and (2) when problem sizes are scaled up to become of practical interest. The present study considers a strategy to improve on these two issues by means of using hybrid radial basis functions that combine cubic splines with Gaussian kernels. The parameters, controlling Gaussian and cubic kernels in the hybrid RBF, are selected using global particle swarm optimization. The proposed approach has been tested with radial basis-pseudospectral method for numerical approximation of Poisson, Helmholtz, and Transport equation. It was observed that the proposed approach significantly reduces the ill-conditioning problem in the RBF-PS method, at the same time, it preserves the stability and accuracy for very small shape parameters. The eigenvalue spectra of the coefficient matrices in the improved algorithm were found to be stable even at large degrees of freedom, which mimic those obtained in pseudospectral approach. Also, numerical experiments suggest that the hybrid kernel performs significantly better than both pure Gaussian and pure cubic kernels.

      PubDate: 2017-05-06T13:52:48Z
       
  • Analysis of meshless weak and strong formulations for boundary value
           problems
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Wajid Khan, Siraj-ul-Islam, Baseer Ullah
      This paper introduces a weak meshless procedure combined with a multi-resolution numerical integration and its comparison with a strong local meshless formulation for approximating displacement and strain modeled in the form of Elliptic Boundary Value Problems (EBVPs) in one- and two-dimensional spaces. Assets and losses of both strong and weak meshless approaches are considered in detail. The meshless weak formulation considered in the current paper is the well-known Element Free Galerkin (EFG) method whereas the Local Radial Basis Functions Collocation Method (LRBFCM) is taken as a strong formulation. First aspect of the current work is implementation of the new numerical integration techniques introduced in Siraj-ul-Islam et al. (2010) and Aziz et al. (2011) [1,2] in the EFG method and its comparison with numerical integration based on standard Gaussian quadrature, adaptive integration and stabilized nodal integration techniques used in the context of EFG and other allied weak meshless formulations. Second aspect of the current work is analysis of comparative performance of the localized versions of strong and weak meshless formulations. Standard numerical tests are conducted to validate performance of both the approaches.

      PubDate: 2017-04-30T13:30:48Z
       
  • Wave interaction with a submerged semicircular porous breakwater placed on
           a porous seabed
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): S. Koley, T. Sahoo
      In the present study, a coupled eigenfunction expansion-boundary element method is developed and used to analyze the interaction of surface gravity waves with a submerged semicircular porous breakwater placed on a porous seabed in water of finite depth. Two separate cases: (a) wave scattering by the semicircular breakwater, and (b) wave trapping by the semicircular breakwater placed near a porous sloping seawall are studied. Further, as a special case, wave trapping by a semicircular breakwater placed on a rubble mound foundation near a sloping seawall is analyzed in water of uniform depth having an impermeable bed. The wave motion through the semicircular permeable arc of the breakwater is modeled using the Darcy's law of fine pore theory, whilst the wave motion through the porous seabed, rubble mound foundation and the porous seawall are modeled using the Sollitt and Cross model. The friction coefficient defined in Sollitt and Cross model is computed by approximating the spatial dependency of the seepage velocity with the average velocity within the porous media. An algorithm for determining the friction coefficient f is provided. Various physical quantities of interests are plotted and analyzed for various values of waves and structural parameters.

      PubDate: 2017-04-30T13:30:48Z
       
  • On modification of pressure gradient operator in integrated ISPH for
           multifluid and porous media flow with free-surface
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Gourabananda Pahar, Anirban Dhar
      In Incompressible Smoothed Particle Hydrodynamics (ISPH) simulation, choice of pressure gradient operator plays an important role. Variations in effective porosity, fluid density, and free-surface conditions dictate the nature of the formulation. This study proposes an integrated ISPH framework with an implicit free-surface treatment. Pressure variation at the multi-fluid interface is maintained using a modified density-weighted pressure gradient with linear momentum conservation. Different pressure gradients with diffused interfaces for a porous domain as well as multifluid interface have been compared with the proposed operator. A unified form of Brinkman and Navier-Stokes equations are utilized to describe the flow-physics inside and outside the porous domain. Density variation in fluids is modelled by solving the scalar-transport equation. Effect of the porous domain is incorporated in terms of varying representative volume of the fluid particles. Porous media interface conditions are implicitly implemented using Darcy velocity and by introducing porosity into Pressure Poisson Equation (PPE). The present model is capable of minimizing error in velocity-divergence due to implicit free-surface treatment combined with linear momentum conservation. Proposed framework is validated by using existing experimental data of density-dependent flow with very low-density ratio and flow through porous blocks. A result of density-current passing through porous domain demonstrates the capability of the developed model for complex scenarios.

      PubDate: 2017-04-30T13:30:48Z
       
  • Degenerate scale for 2D Laplace equation with Robin boundary condition
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): A. Corfdir, G. Bonnet
      It is well known that the 2D Laplace Dirichlet boundary value problem with a specific contour has a degenerate scale for which the boundary integral equation (BIE) has several solutions. We study here the case of the Robin condition (i.e. convection condition for thermal conduction problems), and show that this problem has also one degenerate scale. The cases of the interior problem and of the exterior problem are quite different. For the Robin interior problem, the degenerate scale is the same as for the Dirichlet problem. For the Robin exterior problem, the degenerate scale is always larger than for the Dirichlet problem and has some asymptotic properties. The cases of several simple boundaries like ellipse, equilateral triangle, square and rectangle are numerically investigated and the results are compared with the analytically predicted asymptotic behavior. An important result is that avoiding a contour leading to a degenerate Robin problem cannot be achieved as simply as in the case of Dirichlet boundary condition by introducing a large reference scale into the Green's function.

      PubDate: 2017-04-30T13:30:48Z
       
  • Generalized finite difference method for two-dimensional shallow water
           equations
    • Abstract: Publication date: July 2017
      Source:Engineering Analysis with Boundary Elements, Volume 80
      Author(s): Po-Wei Li, Chia-Ming Fan
      A novel meshless numerical scheme, based on the generalized finite difference method (GFDM), is proposed to accurately analyze the two–dimensional shallow water equations (SWEs). The SWEs are a hyperbolic system of first-order nonlinear partial differential equations and can be used to describe various problems in hydraulic and ocean engineering, so it is of great importance to develop an efficient and accurate numerical model to analyze the SWEs. According to split-coefficient matrix methods, the SWEs can be transformed to a characteristic form, which can easily present information of characteristic in the correct directions. The GFDM and the second-order Runge-Kutta method are adopted for spatial and temporal discretization of the characteristic form of the SWEs, respectively. The GFDM is one of the newly-developed domain-type meshless methods, so the time-consuming tasks of mesh generation and numerical quadrature can be truly avoided. To use the moving-least squares method of the GFDM, the spatial derivatives at every node can be expressed as linear combinations of nearby function values with different weighting coefficients. In order to properly cooperate with the split-coefficient matrix methods and the characteristic of the SWEs, a new way to determine the shape of star in the GFDM is proposed in this paper to capture the wave transmission. Numerical results and comparisons from several examples are provided to verify the merits of the proposed meshless scheme. Besides, the numerical results are compared with other solutions to validate the accuracy and the consistency of the proposed meshless numerical scheme.

      PubDate: 2017-04-30T13:30:48Z
       
 
 
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