P. Fedelinski¹, R. Gorski¹

CMES-Computer Modeling in Engineering & Sciences, Vol.15, No.1, pp. 31-40, 2006, DOI:10.3970/cmes.2006.015.031

Abstract The aim of the present work is to analyze and optimize plates in plane strain or stress with stiffeners subjected to dynamic loads. The reinforced structures are analyzed using the coupled boundary and finite element method. The plates are modeled using the dual reciprocity boundary element method (DR-BEM) and the stiffeners using the finite element method (FEM). The matrix equations of motion are formulated for the plate and stiffeners. The equations are coupled using conditions of compatibility of displacements and equilibrium of tractions along the interfaces between the plate and stiffeners. The final set of… More >

Baohua Ji^*, Yonggang Huang^†

Molecular & Cellular Biomechanics, Vol.3, No.3, pp. 109-120, 2006, DOI:10.3970/mcb.2006.003.109

Abstract The mechanisms governing the self-assembled structure of biomolecules (single chain and bundle of chains) are studied with an AB copolymer model via the coarse grained molecular dynamics simulations. Non-local hydrophobic interaction is found to play a critical role in the pattern formation of the assembled structure of polymer chains. We show that the polymer structure could be controlled by adjusting the balance between local (short range) and non-local (long range) hydrophobic interaction which are influenced by various factors such as the sequences, chain length, stiffness, confinement, and the topology of polymers. In addition, the competition More >

J. Sladek¹, V. Sladek¹, Ch. Zhang², C.L. Tan³

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.1, pp. 57-68, 2006, DOI:10.3970/cmes.2006.016.057

Abstract The Meshless Local Petrov-Galerkin (MLPG) method for linear transient coupled thermoelastic analysis is presented. Orthotropic material properties are considered here. A Heaviside step function as the test functions is applied in the weak-form to derive local integral equations for solving two-dimensional (2-D) problems. In transient coupled thermoelasticity an inertial term appears in the equations of motion. The second governing equation derived from the energy balance in coupled thermoelasticity has a diffusive character. To eliminate the time-dependence in these equations, the Laplace-transform technique is applied to both of them. Local integral equations are written on small More >

T. Ishizawa¹, M. Iura¹

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.3, pp. 121-130, 2006, DOI:10.3970/cmes.2006.011.121

Abstract A one-dimensional model is proposed for numerical analysis of partially concrete-filled steel tubular (PCFST) columns subjected to cyclic loadings. The present formulation does not require experimental results nor shell analysis to obtain the constitutive equation of the model. The material properties and dimensions of PCFST columns are required for numerical analysis of the present model. The PCFST columns are assumed to consist of elastic beam and base plastic-hinge region in which steel local buckling is observed. Two parameters are introduced in order to express hardening phenomena of PCFST columns subjected to cyclic loading. Resisting forces More >

M. Perl¹, C. Levy ², V. Rallabhandy ²

CMES-Computer Modeling in Engineering & Sciences, Vol.11, No.1, pp. 37-48, 2006, DOI:10.3970/cmes.2006.011.037

Abstract The Bauschinger Effect (BE) impact on K_IN– the combined, Mode I, 3-D Stress Intensity Factor (SIF) distributions for arrays of radial, internal, surface cracks emanating from the bore of a fully or partially autofrettaged thick-walled cylinder is investigated. A in-depth comparison between the combined SIFs for a “realistic” - Bauschinger Effect Dependent Autofrettage (BEDA) and those for an “ideal” - Bauschinger Effect Independent Autofrettage (BEIA) is performed. The 3- D finite element (FE) analysis is performed employing the submodeling technique and singular elements along the crack front. Both autofrettage residual stress fields, BEDA and BEIA, are… More >

T. J Jaber¹, M. Khawaja¹, M.Z. Saghir¹

FDMP-Fluid Dynamics & Materials Processing, Vol.2, No.4, pp. 271-286, 2006, DOI:10.3970/fdmp.2006.002.271

Abstract This paper numerically investigates the interaction between thermodiffuion and buoyancy driven convection in a laterally heated vertical porous cavity for different permeability. The Firoozabadi model is applied to binary hydrocarbon mixtures: (i) the mixture of 1,2,3,4 tetrahydronaphtalene (THN) and dodecane (C12) with mass fraction of 50% for each component, (ii) 1,2,3,4 tetrahydronaphtalene and isobutylbenzene (IBB) with mass fraction of 50% for each component, and (iii) isobutylbenzene and dodecane with mass fraction of 50% for each component. The thermal and molecular diffusion coefficients, which are functions of the temperature and other properties of mixture, are calculated More >

S. Smaoui¹, A. Ben Hamida¹, I. Djeran-Maigre², H. Dumontet¹

CMC-Computers, Materials & Continua, Vol.4, No.3, pp. 153-162, 2006, DOI:10.3970/cmc.2006.004.153

Abstract An iterative homogenization approach is proposed in order to predict the nonlinear hydro-mechanical behaviour of porous media. This process is coupled to classical and modified secant extended methods and linear homogenization predictive schemes. At convergence of the iterative process, same equivalent behaviour is obtained for any secant method, any simplified homogenization used for the linear comparison material and for any initial porosity of the media. An application to the study of the nonlinear behaviour of clayey sediments is presented. The model parameters quantification is based on oedometric experimental results for different clays. More >

J. Sladek¹, V. Sladek¹, Ch. Zhang², F. Garcia-Sanche³, M. Wünsche²

CMC-Computers, Materials & Continua, Vol.4, No.2, pp. 109-118, 2006, DOI:10.3970/cmc.2006.004.109

Abstract Piezoelectric materials have wide range engineering applications in smart structures and devices. They have usually anisotropic properties. Except this complication electric and mechanical fields are coupled each other and the governing equations are much more complex than that in the classical elasticity. Thus, efficient computational methods to solve the boundary or the initial-boundary value problems for piezoelectric solids are required. In this paper, the Meshless local Petrov-Galerkin (MLPG) method with a Heaviside step function as the test functions is applied to solve two-dimensional (2-D) piezoelectric problems. The mechanical fields are described by the equations of… More >

Jin Yeon Cho¹, Jae Mo An², You Me Song¹, Seungsoo Lee¹, Dong Whan Choi¹

CMES-Computer Modeling in Engineering & Sciences, Vol.9, No.1, pp. 1-18, 2005, DOI:10.3970/cmes.2005.009.001

Abstract A displacement welding technique is proposed to carry out coupled analysis of the integrated whole model which consists of independently modeled finite element substructures. In the proposed method, the incompatible displacement fields in the interfaces of independently modeled substructures are directly welded together through a blended function that is newly defined in the transient region of mismatching interface. To construct the blended function, the moving least squares function, which does not require well-defined nodal connectivity, is utilized along with the original finite element shape function. The meshless character of the moving least squares function makes More >

W. J. Ferguson¹, B. Palananthakumar²

CMES-Computer Modeling in Engineering & Sciences, Vol.8, No.3, pp. 201-216, 2005, DOI:10.3970/cmes.2005.008.201

Abstract Environmental and safety issues associated with landfill gas require the control of off-site migration. Mathematical modelling can assist in the understanding of the processes and mechanisms controlling gas migration from municipal waste disposal sites. This paper presents the development and application of a mathematical model that simulates landfill gas migration within a partially saturated soil. This model accounts for two-phase flow and incorporates multi-component (methane, carbon dioxide, dry air and moisture) transport in the gas and liquid phases together with concomitant heat migration. The governing system of fully coupled non-linear partial differential equations of the… More >