J. Sladek¹, V. Sladek¹, M. Wünsche², Ch. Zhang²

CMES-Computer Modeling in Engineering & Sciences, Vol.54, No.2, pp. 223-252, 2009, DOI:10.3970/cmes.2009.054.223

Abstract A meshless method based on the local Petrov-Galerkin approach is proposed, to solve the interface crack problem between two dissimilar anisotropic elastic solids. Both stationary and transient mechanical and thermal loads are considered for two-dimensional (2-D) problems in this paper. A Heaviside step function as the test functions is applied in the weak-form to derive local integral equations. Nodal points are spread on the analyzed domain, and each node is surrounded by a small circle for simplicity. The spatial variations of the displacements and temperature are approximated by the Moving Least-Squares (MLS) scheme. After performing the spatial integrations, one obtains… More >

Chien-Ching Ma^1,2, Jui-Mu Lee²

CMES-Computer Modeling in Engineering & Sciences, Vol.54, No.1, pp. 87-120, 2009, DOI:10.3970/cmes.2009.054.087

Abstract In this study, the two-dimensional problem of elastic, electric, and magnetic fields induced by generalized line forces and screw dislocations applied in a functionally graded magnetoelectroelastic layered half-plane is analyzed. It is assumed that the material properties vary exponentially along the thickness direction. The full-field solutions for the transversely isotropic magnetoelectroelastic nonhomogeneous layered half-plane are obtained using the Fourier-transform technique. For the case that material properties are continuous at the interface, it is shown that all magnetoelectroelastic fields are continuous at the interface. Furthermore, this functionally graded layered half-plane has the identical contour slopes for the generalized stress \pmbsy(j)across the… More >

Sudib K. Mishra¹, J. K. Paik², S. N. Atluri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.50, No.1, pp. 67-96, 2009, DOI:10.3970/cmes.2009.050.067

Abstract We present a simulation based study, by combining several models involving multiple time scales and physical processes, which govern the interfacial stress corrosion cracking (SCC) in grain boundaries, layered composites or bi-materials, and the mechanisms of inhibition using `smart' agents. The inhibiting agents described herein, automatically sense the initiation of damage, migrate to the sites and delay the corrosion kinetics involved in the process. The phenomenon of SCC is simulated using the lattice spring model (for the mechanical stresses), coupled with a finite difference model of diffusing species, causing the dissolution of the interfacial bonds. The dissolution is expressed through… More >

Ronan Madec¹, Dimitri Komatitsch^1,2, Julien Diaz³

CMES-Computer Modeling in Engineering & Sciences, Vol.49, No.2, pp. 163-190, 2009, DOI:10.3970/cmes.2009.049.163

Abstract When studying seismic wave propagation in fluid-solid models based on a numerical technique in the time domain with an explicit time scheme it is often of interest to resort to time substepping because the stability condition in the solid part of the medium can be more stringent than in the fluid. In such a case, one should enforce the conservation of energy along the fluid-solid interface in the time matching algorithm in order to ensure the accuracy and the stability of the time scheme. This is often not done in the available literature and approximate techniques that do not enforce… More >

J. M. García-Aznar^1,2, M. A. Pérez^1,2, P. Moreo^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.3, pp. 271-302, 2009, DOI:10.3970/cmes.2009.048.271

Abstract There are many interfaces between biological materials with a structural functionality, where their mechanical behaviour is crucial for their own performance. Advanced tools such as cohesive surface models are being used to simulate the failure and degradation of this kind of biological interactions. The goal of this paper, in a first step, is to present some cohesive surface models that include damage and repair in interfaces and its application to different biomechanical problems. Secondly, we discuss about the main challenges that we have to improve in the modelling of interfaces for a mechanobiological approach. More >

M.V. Menshykova¹, O.V. Menshykov, I.A. Guz

CMES-Computer Modeling in Engineering & Sciences, Vol.48, No.2, pp. 107-120, 2009, DOI:10.3970/cmes.2009.048.107

Abstract The study is devoted to the problem for a linear crack located between two dissimilar elastic half-spaces under normally incident time-harmonic plane shear wave. The system of boundary integral equations for displacements and tractions is derived from the dynamic Somigliana identity. The distributions of the displacements and tractions at the bonding interface and the surface of the crack are analysed. The dynamic stress intensity factors (the opening and the transverse shear modes) are computed as functions of the frequency of the incident wave for different material properties. More >

Dongdong Wang^1,2, Yue Sun², Ling Li²

CMES-Computer Modeling in Engineering & Sciences, Vol.45, No.1, pp. 57-82, 2009, DOI:10.3970/cmes.2009.045.057

Abstract A discontinuous Galerkin meshfree formulation is proposed to solve the potential and elasticity problems of composite material where the material interface has to be appropriately modeled. In the present approach the problem domain is partitioned into patches or sub-domains and each patch holds the same material properties. The discretized meshfree particles within a patch are classified as one particle group. Various patches occupied by different particle groups are then linked using the discontinuous Galerkin formulation where an averaged interface flux or traction is constructed based on the fluxes or tractions computed from the adjacent patches. The gradient jump condition across… More >

S.H. Pyo¹, H.K. Lee^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.40, No.3, pp. 271-306, 2009, DOI:10.3970/cmes.2009.040.271

Abstract This paper presents a micromechanical approach for predicting the elastic and multi-level damage response of aligned and randomly oriented whisker-/ short fiber-reinforced composites. Based on a combination of Eshelby's micromechanics and the evolutionary imperfect interface approach, the effective elastic moduli of the composites are derived explicitly. The modified Eshelby's tensor for spheroidal inclusions with slightly weakened interface [Qu (1993b)] is extended in the present study to model whiskers or short fibers having mild or severe imperfect interfaces. Aligned and random orientations of spheroidal reinforcements are considered. A multi-level damage model in accordance with the Weibull's probabilistic function is then incorporated… More >

W. Attaporn¹, H. Koguchi²

CMES-Computer Modeling in Engineering & Sciences, Vol.39, No.3, pp. 237-262, 2009, DOI:10.3970/cmes.2009.039.237

Abstract In the present study, a stress singularity field along free edges meeting at a corner in a three-dimensional joint structure is investigated. The order of stress singularity is determined using an eigen analysis based on a finite element method. Intensities of stress singularity not only at the corner but also along the free edge of interface are determined directly without any post-processing by a new FEM formulation referred to as a three-dimensional enriched FEM. Result in the present analysis is also compared with that in another numerical method. It was slightly larger than the intensity of stress singularity, which was… More >

L. Mai-Cao¹, T. Tran-Cong²

CMES-Computer Modeling in Engineering & Sciences, Vol.31, No.3, pp. 157-188, 2008, DOI:10.3970/cmes.2008.031.157

Abstract This paper presents a new meshless numerical approach to solving a special class of moving interface problems known as the passive transport where an ambient flow characterized by its velocity field causes the interfaces to move and deform without any influences back on the flow. In the present approach, the moving interface is captured by the level set method at all time as the zero contour of a smooth function known as the level set function whereas one of the two new meshless schemes, namely the SL-IRBFN based on the semi-Lagrangian method and the Taylor-IRBFN scheme based on Taylor series… More >