Shardool U. Chirputkar¹, Dong Qian²

CMES-Computer Modeling in Engineering & Sciences, Vol.24, No.2&3, pp. 185-202, 2008, DOI:10.3970/cmes.2008.024.185

Abstract A multiscale method based on the extended space-time finite element method is developed for the coupled atomistic/continuum simulation of nanoscale material systems. Existing single scale approach such as the finite element method has limited capability of representing the fine scale physics in both the spatial and temporal domains. This is a major disadvantage for directly incorporating FEM in coupled atomistic/continuum simulations as it results in errors such as spurious wave reflections at the atomistic/continuum interface. While numerous efforts have been devoted to eliminating the interfacial mismatch effects, less attention has been paid to developing fine More >

H. Nguyen-Van¹, N. Mai-Duy², T. Tran-Cong³

CMES-Computer Modeling in Engineering & Sciences, Vol.23, No.3, pp. 209-222, 2008, DOI:10.3970/cmes.2008.023.209

Abstract This paper reports a study of linear elastic analysis of two-dimensional piezoelectric structures using a smoothed four-node piezoelectric element. The element is built by incorporating the strain smoothing method of mesh-free conforming nodal integration into the standard four-node quadrilateral piezoelectric finite element. The approximations of mechanical strains and electric potential fields are normalized using a constant smoothing function. This allows the field gradients to be directly computed from shape functions. No mapping or coordinate transformation is necessary so that the element can be used in arbitrary shapes. Through several examples, the simplicity, efficiency and reliability More >

Asif Husain¹, M. Guniganti², D. K. Sehgal², R. K. Pandey²

CMC-Computers, Materials & Continua, Vol.8, No.3, pp. 133-150, 2008, DOI:10.3970/cmc.2008.008.133

Abstract This paper describes an approach to identify the mechanical properties i.e. fracture and yield strength of steels. The study involves the FE simulation of shear punch test for various miniature specimens thickness ranging from 0.20mm to 0.80mm for four different steels using ABAQUS code. The experimental method of the miniature shear punch test is used to determine the material response under quasi-static loading. The load vs. displacement curves obtained from the FE simulation miniature disk specimens are compared with the experimental data obtained and found in good agreement. The resulting data from the load vs.… More >

M. M. Rahman¹, A. K. Ariffin², S. Abdullah², A. B. Rosli¹

Structural Durability & Health Monitoring, Vol.3, No.4, pp. 197-210, 2007, DOI:10.3970/sdhm.2007.003.197

Abstract Low weight and long lifetime are necessary requirements for automobiles to significantly reduce CO₂ emission and environmental burdens in their use. Aluminum alloys are one of the most promising materials selections for automobiles parts and electrical components to reduce their weight and to increase their specific strength. This paper presents the role of nitriding on the fatigue life of the vibrating cylinder block for a new two-stroke free piston engine using variable amplitude loading conditions. The finite element modeling and analysis have been performed utilising a computer aided design and a finite element analysis codes respectively.… More >

B. Gatmiri¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.3, pp. 159-166, 2007, DOI:10.3970/icces.2007.004.159

Abstract This document summarizes the basic concepts and steps of establishment of the set of equations of wave propoagation in far field and of the dynamic behaviour of porous media in the near field. A breif description of HYBRID software as a powerful tool for evaluation of local seismic site effect is presented. The Combination of the FEM and BEM and improvement of numerical algorithm for the time truncation are described. More >

Kazuhiko Kakuda¹, Tomohiro Aiso¹, Shinichiro Miura²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.1, pp. 11-18, 2007, DOI:10.3970/icces.2007.004.011

Abstract The applications of a finite element scheme to three-dimensional incompressible viscous fluid flows are presented. The scheme is based on the Petrov-Galerkin weak formulation with exponential weighting functions. The incompressible Navier-Stokes equations are numerically integrated in time by using a fractional step strategy with second-order accurate Adams-Bashforth scheme for both advection and diffusion terms. Numerical solutions for flow around a circular cylinder and flow around a railway vehicle in a tunnel are presented. More >

Hong-ying Huang^2,1, De-hao Yu ²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.3, pp. 67-74, 2007, DOI:10.3970/icces.2007.002.067

Abstract In this paper, we apply the coupling of natural boundary element method and finite element method to solve a three-dimensional nonlinear interface problem. Two equations are coupled by interface conditions on the interface boundary. A spherical surface as the artificial boundary is introduced. The equivalent coupled variational problem is described. The existence and uniqueness of the solution of concerned problem as well as the estimates of its approximate solution are obtained. Some numerical examples are presented to demonstrate the effectiveness of this method. More >

J. Li¹, Z.H. Xiang¹, M.D. Xue¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.1, pp. 7-12, 2007, DOI:10.3970/icces.2007.002.007

Abstract This paper presents a finite element scheme to analyze the buckling behavior of composite shells subjected to thermal and mechanical loads. Firstly, a kind of multi-layered composite shell element with relative degrees-of-freedom is adopted to model laminated composite shells. Then the corresponding temperature element is developed so that the mechanical analysis and the thermal analysis share a common mesh. Moreover, a new criterion of critical heat flux is proposed in stead of the traditional criterion of critical temperature. Finally, the advantage of the proposed scheme is illustrated by calculating the stable region of thermal-mechanical loads More >

Atsuya Oishi¹, Shinobu Yoshimura²

CMES-Computer Modeling in Engineering & Sciences, Vol.21, No.2, pp. 93-104, 2007, DOI:10.3970/cmes.2007.021.093

Abstract This paper describes a new local contact search method using a multi-layer neural network and its application to smoothed contact surface consisting of Gregory patches. A contact search process consists of two phases: a global search phase for finding the nearest node-segment pair and a local search phase for finding an exact local coordinate of the contact point within the segment. In the present method, the multi-layer neural network is utilized in the latter phase. The fundamental formulation of the proposed local contact search method is described in detail, and it is applied to smoothed More >

Chun Yang¹, Dalin Tang², Chun Yuan³, Thomas S. Hatsukami⁴, Jie Zheng⁵, Pamela K. Woodard⁵

CMES-Computer Modeling in Engineering & Sciences, Vol.19, No.3, pp. 233-246, 2007, DOI:10.3970/cmes.2007.019.233

Abstract It has been recognized that fluid-structure interactions (FSI) play an important role in cardiovascular disease initiation and development. However, in vivo MRI multi-component FSI models for human carotid atherosclerotic plaques with bifurcation and quantitative comparisons of FSI models with fluid-only or structure-only models are currently lacking in the literature. A 3D non-Newtonian multi-component FSI model based on in vivo/ex vivo MRI images for human atherosclerotic plaques was introduced to investigate flow and plaque stress/strain behaviors which may be related to plaque progression and rupture. Both artery wall and plaque components were assumed to be hyperelastic,… More >