Luming Shen¹, Zhen Chen²

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.3, pp. 305-320, 2005, DOI:10.3970/cmes.2005.007.305

Abstract To simulate the dynamic responses involving different material phases in a finite computational domain without discretizing the whole problem domain, a silent boundary scheme is proposed within the framework of the material point method (MPM) that is an extension from Computational Fluid Dynamics to Computational Solid Dynamics. Because the MPM does not employ fixed mesh connectivity, a robust spatial discretization procedure in the moving domain of influence could be designed by applying viscous damping forces along the computational boundary. To establish a simple interface between the discretization procedures with and without fixed mesh connectivity, a More >

Dan Givoli¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.6, pp. 497-514, 2004, DOI:10.3970/cmes.2004.005.497

Abstract Very thin layers with material properties which significantly differ from those of the surrounding medium appear in a variety of applications. Traditionally there are two extreme ways of handling such layers in finite element analysis: either they are fully modelled or they are totally ignored. The former option is often very expensive computationally, while the latter may lead to significant inaccuracies. Here a special technique of modeling thin layers is devised within the framework of the finite element method. This technique constitutes a prudent compromise between the two extremes mentioned above. The layer is replaced More >

W. Li¹ and T. Siegmund¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.1, pp. 81-90, 2004, DOI:10.3970/cmes.2004.005.081

Abstract Results of a computational study of the mechanics of indentation induced interface delamination are described for a system consisting of a ductile film on an elastic substrate. Special attention is paid to the properties of the interface between film and substrate, and the influence of the interface properties on the indentation response. Specifically, strong interfaces are considered. The interface is characterized by the use of a cohesive zone model. The finite element method is used to solve the boundary value problem, with the interface behavior incorporated via a cohesive model in a traction-separation formulation. The More >

L. Chernin¹, K.Y. Volokh^1,2

CMC-Computers, Materials & Continua, Vol.1, No.3, pp. 259-274, 2004, DOI:10.3970/cmc.2004.001.259

Abstract The conventional approach to analysis of thin film delamination is based on the consideration of the film, which is subjected to residual stresses arising from the thermal mismatch between the film and the substrate, within the framework of the classical fracture mechanics and the structural buckling theories. Such concepts as the energy release rate and the stress intensity factors are crucial in this case.

A different approach to analysis of thin film delamination considers the effect of the compliant interface between the film and the substrate. This compliant interface is described by the traction-separation… More >

T. Iwasaki¹ and H. Miura¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.5, pp. 551-558, 2003, DOI:10.3970/cmes.2003.004.551

Abstract We have developed a molecular-dynamics technique for investigating migration-induced failures in interconnect films for ULSIs. This technique was used to simulate grain-boundary grooving in Al and Cu films. The simulations showed that the grain-boundary grooves are formed by atomic diffusion at the grain boundary. To clarify what kind of underlay material is effective in suppressing this diffusion, we calculated the dependence of groove depth on the kind of underlay material. The calculation showed that the groove depth of the Al film decreases in the order: Al/Ta, Al/W, and Al/TiN while that of the Cu film More >

W. C. Liu, S. Q. Shi, C. H. Woo, Hanchen Huang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.3, No.2, pp. 213-218, 2002, DOI:10.3970/cmes.2002.003.213

Abstract Using molecular dynamics method, we study the nucleation of dislocations and their subsequent propagation during the deposition of tungsten thin films under tension. Aiming to reveal the generic mechanisms of dislocation nucleation during the deposition of polycrystalline thin films, the case of tungsten on a substrate of the same material is considered. The substrate is under uniaxial tension along the [111] direction, with the thermodynamically favored (01^ˉˉ1) surface being horizontal. The simulation results indicate that the nucleation starts with a surface step, where a surface atom is pressed into the film along the [111^ˉˉ] More >

Xiaolin Chen, Yijun Liu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.2, No.3, pp. 337-350, 2001, DOI:10.3970/cmes.2001.002.337

Abstract An advanced boundary element method (BEM) is developed in this paper for analyzing thin layered structures, such as thin films and coatings, under the thermal loading. The boundary integral equation (BIE) formulation for steady-state thermoelasticity is reviewed and a special case, that is, the BIE for a uniform distribution of the temperature change, is presented. The new nearly-singular integrals arising from the applications of the BIE/BEM to thin layered structures under thermal loading are treated in the same way as developed earlier for thin structures under the mechanical loading. Three 2-D test problems involving layered More >

V . Bontozoglou¹

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.2, pp. 133-142, 2000, DOI:10.3970/cmes.2000.001.293

Abstract Laminar, gravity-driven flow of a liquid down an inclined wall with large-amplitude sinusoidal corrugations is studied numerically by a spectral spatial discretization method. The synchronous resonance between the wall and the free surface is investigated for corrugations with wavelength 0.002 m, which – according to linear theory – lead to strongest interaction. Free surface profile and flow structure are studied as a function of the film Reynolds number and the wall amplitude. Streamline patterns are computed and conditions leading to flow reversal are established. The distribution of the shear stress along the wall and of the More >