Open Access
ARTICLE
A.I. Abreu1, W.J. Mansur1, D. Soares Jr1,2, J.A.M. Carrer3
CMES-Computer Modeling in Engineering & Sciences, Vol.30, No.3, pp. 123-132, 2008, DOI:10.3970/cmes.2008.030.123
Abstract This paper is concerned with the numerical computation of space derivatives of a time-domain (TD-) Boundary Element Method (BEM) formulation for the analysis of scalar wave propagation problems. In the present formulation, the Convolution Quadrature Method (CQM) is adopted, i.e., the basic integral equation of the TD-BEM is numerically substituted by a quadrature formula, whose weights are computed using the Laplace transform of the fundamental solution and a linear multi-step method. In order to numerically compute space derivatives, the present work properly transforms the quadrature weights of the CQM-BEM, adopting the so-called Complex-Variable-Differentiation Method (CVDM). Numerical examples are presented at… More >
Open Access
ARTICLE
P.H. Wen1, M.H. Aliabadi2, Y.W. Liu3
CMES-Computer Modeling in Engineering & Sciences, Vol.30, No.3, pp. 133-148, 2008, DOI:10.3970/cmes.2008.030.133
Abstract Based on the variation of potential energy, the element-free Galerkin method (MFGM) has been investigated for structures with crack on the basis of radial base function interpolation. An enriched radial base function is introduced to capture the singularities of stress at the crack tips. The advantages of the finite element method are remained in this method and there is a significant improvement of accuracy, particularly for the crack problems of fracture mechanics. The applications of the element-free Galerkin method with enriched radial base function to two-dimensional fracture mechanics in functionally graded materials have been presented and comparisons have been made… More >
Open Access
ARTICLE
Dong Ju Woo1, Jin Oh Yang1, Beom-Soo Kim1, Seungsoo Lee1, Jin Yeon Cho2
CMES-Computer Modeling in Engineering & Sciences, Vol.30, No.3, pp. 149-162, 2008, DOI:10.3970/cmes.2008.030.149
Abstract A new orphan-cell-free overset method is proposed to carry out the coupled analysis of overlapping finite element substructures. In the proposed overset method, the meshless MLS (Moving Least Squares) approximation is used to obtain the boundary data for the overlapped interface, whereas the Lagrange interpolation scheme has been commonly used in the conventional overset methods. The meshless character of MLS approximation makes it possible to overcome the problem of orphan-cell, which is often encountered in the conventional overset methods. Further, a new connectivity matrix solution procedure is developed to reduce the computational time in the coupled analysis as a part… More >
Open Access
ARTICLE
E. Ferretti1, E. Casadio, A. Di Leo1
CMES-Computer Modeling in Engineering & Sciences, Vol.30, No.3, pp. 163-190, 2008, DOI:10.3970/cmes.2008.030.163
Abstract In this study, the Cell Method (CM) is applied in order to investigate the failure mechanisms of masonry walls under shear force. The direction of propagation is computed step-wise by the code, and the domain is updated by means of a propagation technique of intra-element nodal relaxation with re-meshing. The crack extension condition is studied in the Mohr/Coulomb plane, using the criterion of Leon. The main advantage of using the CM for numerical analyses of masonry is that the mortar, the bricks and the interfaces between mortar and bricks can be modeled without any need to use homogenization techniques, simply… More >