Open Access
ARTICLE
Chun-Ying. Wu1, R. Al-Khoury2, C. Kasbergen2, Xue-Yan. Liu2, A. Scarpas2
CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.3, pp. 163-172, 2007, DOI:10.3970/cmes.2007.017.163
Abstract 3D spectral element method in the article is presented to predict the pavement layer modules using field measurement of Falling Weight Deflectometer (FWD). To improve the computational efficiency of the layer-condition assessment, one type of spectral element is proposed to develop the dynamic analysis of 3D multi-layered system subjected to an impulsive load. Each layer in structure is simulated as two-noded layer spectral element or one-noded spectral element in frequency domain. In order to identify the parameters of layered structures, a nonlinear optimization method called Powell hybrid algorithm is employed. The optimization procedure is performed in frequency domain and aims… More >
Open Access
ARTICLE
R. Vodička1, V. Mantič2, F. París2
CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.3, pp. 173-204, 2007, DOI:10.3970/cmes.2007.017.173
Abstract An original approach to solve domain decomposition problems by the symmetric Galerkin boundary element method is developed. The approach, based on a new variational principle for such problems, yields a fully symmetric system of equations. A natural property of the proposed approach is its capability to deal with nonconforming discretizations along straight and curved interfaces, allowing in this way an independent meshing of non-overlapping subdomains to be performed. Weak coupling conditions of equilibrium and compatibility at an interface are obtained from the critical point conditions of the energy functional. Equilibrium is imposed through local traction (Neumann) boundary conditions prescribed on… More >
Open Access
ARTICLE
A.N. Guz1, O.V. Menshykov1,2, V.V. Zozulya3, I.A. Guz2
CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.3, pp. 205-214, 2007, DOI:10.3970/cmes.2007.017.205
Abstract The contact interaction of opposite faces of an elliptical crack is studied for the case of a normal time-harmonic shear wave loading. The distribution of stress intensity factors (shear modes II and III) as functions of the wave number and the friction coefficient is investigated. The results are compared with those obtained for an elliptical crack without allowance for the contact interaction. More >
Open Access
ARTICLE
J.A. Sanz, M. Solis, J. Dominguez1
CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.3, pp. 215-230, 2007, DOI:10.3970/cmes.2007.017.215
Abstract A general mixed boundary element formulation for three-dimensional piezoelectric fracture mechanics problems is presented in this paper. The numerical procedure is based on the extended displacement and traction integral equations for external and crack boundaries, respectively. Integrals with strongly singular and hypersingular kernels appearing in the formulation are analytically transformed into weakly singular and regular integrals. Quadratic boundary elements and quarter-point boundary elements are implemented in a direct way in a computer code. Electric and stress intensity factors are directly computed from nodal values at quarter-point elements. Crack problems in 3D piezoelectric bounded and unbounded solids are solved. The obtained… More >
Open Access
ARTICLE
T. Nishioka1, Y. Kobayashi1, T. Fujimoto1
CMES-Computer Modeling in Engineering & Sciences, Vol.17, No.3, pp. 231-238, 2007, DOI:10.3970/cmes.2007.017.231
Abstract First, for growing cracks in elastic-plastic materials, an incremental variational principle is developed to satisfy the boundary conditions near newly created crack surfaces. Then using this variational principle, a moving finite element method is formulated and developed, based on the Delaunay automatic triangulation. Furthermore, theoretical backgrounds on numerical prediction for fracture path of curving crack using T* integral are explained. Using the automatic moving finite element method, fracture-path prediction simulations are successfully carried out. More >