G.D. Hatzigeorgiou¹, D.E. Beskos¹

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.6, pp. 791-802, 2002, DOI:10.3970/cmes.2002.003.791

Abstract This paper presents a general boundary element methodology for the dynamic analysis of three-dimensional inelastic solids and structures. Inelasticity is simulated with the aid of the continuum damage theory. The elastostatic fundamental solution is employed in the integral formulation of the problem and this creates in addition to the surface integrals, volume integrals due to inertia and inelasticity. Thus an interior discretization in addition to the usual surface discretization is necessary. Isoparametric linear quadrilateral elements are used for the surface discretization and isoparametric linear hexahedra for the interior discretization. Advanced numerical integration techniques for singular and nearly singular integrals are… More >

N. Sukumar¹, J. E. Bolander¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.6, pp. 691-706, 2003, DOI:10.3970/cmes.2003.004.691

Abstract In this paper, we explore the numerical approximation of discrete differential operators on non-uniform grids. The Voronoi cell and the notion of natural neighbors are used to approximate the Laplacian and the gradient operator on irregular grids. The underlying weight measure used in the numerical computations is the {\em Laplace weight function}, which has been previously adopted in meshless Galerkin methods. We develop a difference approximation for the diffusion operator on irregular grids, and present numerical solutions for the Poisson equation. On regular grids, the discrete Laplacian is shown to reduce to the classical finite difference scheme. Two techniques to… More >

Jan Sladek¹, Vladimir Sladek¹, Chuanzeng Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.6, pp. 637-648, 2003, DOI:10.3970/cmes.2003.004.637

Abstract A new computational method for solving transient elastodynamic initial-boundary value problems in continuously non-homogeneous solids, based on the meshless local Petrov-Galerkin (MLPG) method, is proposed in the present paper. The moving least squares (MLS) is used for interpolation and the modified fundamental solution as the test function. The local Petrov-Galerkin method for unsymmetric weak form in such a way is transformed to the local boundary integral equations (LBIE). The analyzed domain is divided into small subdomains, in which a weak solution is assumed to exist. Nodal points are randomly spread in the analyzed domain and each one is surrounded by… More >

J. Sladek, V. Sladek, M. Wonsche, Ch. Zhang

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 79-80, 2011, DOI:10.3970/icces.2011.018.079

Abstract It is well known that the coupling nature of piezoelectric materials has led to their wide applications. Interface failure is one of the most dominant failure mechanisms in laminated piezoelectric elements and structures. A meshless method based on the local Petrov-Galerkin approach is proposed, to solve the interface crack problem between two dissimilar piezoelectric solids. Permeable and impermeable electrical boundary conditions are considered on the crack faces. Stationary governing equations for electrical fields and the elastodynamic equations with an inertial term for two-dimensional (2-D) mechanical fields are considered. Nodal points are spread on the analyzed domain, and each node is… More >

D.-A. An-Vo, N. Mai-Duy, T. Tran-Cong

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.3, pp. 87-88, 2011, DOI:10.3970/icces.2011.016.087

Abstract In this paper, we develop a control-volume technique based on 2-node integrated-radial-basis-function elements (IRBFEs) for the numerical solution of steady incompressible flows governed by the stream function-vorticity formulation. The fluid domain is discretised by a Cartesian grid from which non-overlapping rectangular control- volumes are formed. Line integrals arising from the integration of the diffusion and convection terms over control volumes are evaluated using the middle-point rule. The convection term is effectively treated by the upwind scheme with deferred correction strategy. Instead of using conventional low-order polynomials, all physical quantities at the interfaces are presently estimated by means of 2-node IRBFEs.… More >

Ju E Yang, Qiya Hu, Dehao Yu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.3, pp. 71-72, 2011, DOI:10.3970/icces.2011.016.071

Abstract In this paper, based on the natural boundary reduction method advanced bu Feng and Yu, we are concerned with a domain decomposition method with nonmatching grids for a certain nonlinear interface problem in unbounded domains. We first discuss a new coupling of finite element and boundary element by adding an auxiliary circle. Then we use a dual basis multipier on the interface to provide the numerical analysis with nonmatching grids. Finally, we give some numerical examples further to confirm our theoretical results. More >

Y.C. Shiah, C.L. Tan

The International Conference on Computational & Experimental Engineering and Sciences, Vol.16, No.1, pp. 31-32, 2011, DOI:10.3970/icces.2011.016.031

Abstract In the boundary element method (BEM), interior point solutions for the displacements and the stresses at an interior point of an elastic body are obtained through the numerical evaluation of the Somigliana's identities. It is carried out as a secondary exercise in the BEM analysis, after the boundary integral equation (BIE) has been solved for all the unknown displacements and tractions on the surface of the domain. In the integrals of these identities, the integrands contain terms with up to second order derivatives of the Green's function for the displacements of the elastic problem.

The Green's function, or fundamental… More >

Jichang Wang, Xiaoming Guo^*, Xiaoxiao Sun

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 79-79, 2019, DOI:10.32604/icces.2019.05248

Abstract Cement mortar is an important component of many composite materials and one of the most widely used materials in engineering construction. At microscopic level, cement mortar can be regarded as a multiphase material composed of fine aggregates, cement paste, and a great many of initial defects, the form of which are micro-cracks and micro-voids. The macroscopic properties of cement mortar will be influenced by mechanical properties of different constituents and complex internal structures. The microscopic model containing micro-voids is established by the method of secondary development. The process of cement mortar damage fracture is studied. The fracture toughness of fine… More >

Zumei Zheng¹, Naoto Mitsume¹, Guangtao Duan¹, Shunhua Chen^1,*, Tomonori Yamada¹, Shinobu Yoshimura¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.3, pp. 59-59, 2019, DOI:10.32604/icces.2019.05279

Abstract The interactions between fluids and complicated solid structures are common phenomena in practical engineering applications, e.g., water-tire interaction in the hydroplaning problem. In this work, we advocate the coupled explicit moving particle simulation method and the finite element method (EMPS-FEM) to solve this problem, where the EMPS is used to describe the fluid flow and the FEM is for structural deformation. In the existing EMPS-FEM method, the interface interaction between the fluid and the structure is solved by an explicitly represented polygon (ERP) wall boundary model. For the situations with complicated solid structures, e.g.,angled edges, the ERP model attempts to… More >

N. Mai-Duy¹, T. Tran-Cong¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.14, No.2, pp. 51-56, 2010, DOI:10.3970/icces.2010.014.051

Abstract This paper presents a preconditioning scheme to improve the condition number of integrated radial-basis-function (RBF) matrices in solving large-scale 2D elliptic problems. The problem domain is discretised using a Cartesian grid, over which integrated RBF networks are employed to represent the field variable. The present preconditioner is constructed from 1D integrated RBF networks along grid lines. Test problems defined on rectangular and non-rectangular domains are employed to study the performance of the scheme. More >