A.B. Mahmud Hasan^1,2, M A Wahab¹, S.M. Guo¹

Structural Durability & Health Monitoring, Vol.4, No.4, pp. 231-240, 2008, DOI:10.3970/sdhm.2008.004.231

Abstract This paper presents details analysis of Heat Affected Zone (HAZ) in High Temperature Vacuum Tube Furnace (HTVTF) to predict fracture region in tube wall due to thermal stress from temperature variation across its thickness. A simple mathematical model is used to illustrate stress concentration arising due to thermal stresses in tube wall and HAZs. Finite element model and analysis were carried out utilizing finite element analysis commercial codes. Combination of thermal stress due to temperature difference determine fracture region. Experimental and simulation results of inside temperature of tube are observed and similar relation have been More >

M. M. Rahman¹, A. K. Arrifin², M. J. M. Nor², S. Abdullah²

Structural Durability & Health Monitoring, Vol.4, No.3, pp. 173-180, 2008, DOI:10.3970/sdhm.2008.004.173

Abstract This paper presents the fatigue analysis of spot-weld joints for automative structures to predict the lifetime and location of the weakest spot-welds due to the imposed loading conditions. A simple model was used to illustrate the technique of spot-weld fatigue analysis. Finite element model and analysis were carried out utilizing the finite element analysis commercial codes. Linear elastic finite element analysis was carried out to predict the stress state along the weld direction. It can be seen from the results that the predicted life greatly influence the sheet thickness, spot diameter and loading conditions of More >

Zdenko Tonković¹, Jurica Sorić^1,2, Ivica Skozrit¹

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.2, pp. 75-90, 2008, DOI:10.3970/cmes.2008.026.075

Abstract An efficient numerical algorithm for modeling of cyclic elastoplastic deformation of shell structures is derived. The constitutive model includes highly nonlinear multi-component forms of kinematic and isotropic hardening functions in conjunction with von Mises yield criterion. Therein, the closest point projection algorithm employing the Reissner-Mindlin type kinematic model, completely formulated in tensor notation, is applied. A consistent elastoplastic tangent modulus ensures high convergence rates in the global iteration approach. The integration algorithm has been implemented into a layered assumed strain isoparametric finite shell element, which is capable of geometrical nonlinearities including finite rotations. Numerical examples, More >

Amit Shaw¹, B. Banerjee¹, D Roy^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.1, pp. 31-60, 2008, DOI:10.3970/cmes.2008.026.031

Abstract A generalization of a NURBS based parametric mesh-free method (NPMM), recently proposed by Shaw and Roy (2008), is considered. A key feature of this parametric formulation is a geometric map that provides a local bijection between the physical domain and a rectangular parametric domain. This enables constructions of shape functions and their derivatives over the parametric domain whilst satisfying polynomial reproduction and interpolation properties over the (non-rectangular) physical domain. Hence the NPMM enables higher-dimensional B-spline based functional approximations over non-rectangular domains even as the NURBS basis functions are constructed via the usual tensor products of… More >

L.M. Xu¹, H. Fan^2,3, X M Xie³, C. Li³

CMC-Computers, Materials & Continua, Vol.7, No.3, pp. 119-128, 2008, DOI:10.3970/cmc.2008.007.119

Abstract In the present study we performed finite element simulation for bi-continuous heterogeneous solids via a random distribution of materials to predict effective elastic properties. With a random distributing scheme, a statistical analysis via finite element becomes feasible for the multi-phase heterogeneous solids. Using a two-phase bi-continuous material as example, the numerical prediction of the effective properties is obtained in terms of a mean value and standard deviation with a sample size of 30 for each of given volume fraction. The finite element simulation results fall within the analytical bounds proposed by Hashin and Shtrikman (1963) More >

Jin Yeon Cho¹, Yun Hyuk Choi², You Me Song³, Chang Sik Kim⁴

The International Conference on Computational & Experimental Engineering and Sciences, Vol.4, No.3, pp. 151-158, 2007, DOI:10.3970/icces.2007.004.151

Abstract In this work, PDSL(pre-detection sort last) and SDSL(strip-wise decomposition sort last) parallel visualization algorithms are proposed for efficient visualization of massive data generated from large-scale parallel finite element analysis through investigating the characteristics of distributed parallel finite element analysis procedure. The proposed parallel visualization algorithms are based on the sort last approach, and designed to be highly compatible with the characteristics of domain-wise computation in parallel finite element analysis. To investigate the performances of proposed algorithms, in-house software is developed by applying the binary tree network communication pattern along with the proposed sorting algorithms, and More >

M-A Lavoie¹, A. Gakwaya¹, M. Nejad Ensan², D.G. Zimcik²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.2, No.4, pp. 111-118, 2007, DOI:10.3970/icces.2007.002.111

Abstract This paper reviews numerical methods that are currently available to simulate bird strike as well as the theory of the event. It also summarizes important parameters and provides guidelines as to how to set up the analysis and how to evaluate a model. The information provided is based on physical properties and available results regarding a bird and its behaviour upon impact. The simulations have been performed with LS-DYNA 970 but can be done in similar dynamic finite elements analysis codes. More >

D. Moens¹, M. De Munck, D. Vandepitte

CMES-Computer Modeling in Engineering & Sciences, Vol.22, No.2, pp. 129-150, 2007, DOI:10.3970/cmes.2007.022.129

Abstract Recently, an interval finite element methodology has been developed to calculate envelope frequency response functions of uncertain structures with interval parameters. The methodology is based on a hybrid interval implementation of the modal superposition principle. This hybrid procedure consists of a preliminary optimization step, followed by an interval arithmetic procedure. The final envelope frequency response functions have been proved to give a very good approximation of the actual response range of the interval problem. Initially, this method was developed for undamped structures. Based on the theoretical principles of this approach, this paper introduces a new… More >

Shuji Takashima¹, Michihiko Nakagaki², Noriyuki Miyazaki¹

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.3, pp. 193-202, 2007, DOI:10.3970/cmes.2007.020.193

Abstract Composite materials have complicated microstructures. These microstructures affect the macroscopic deformation of composite materials. In the present study, we focus on the effect of particle size in a particle-dispersed composite material on the mechanical strength of the material. For this purpose, we derived a macroscopic elastic-plastic constitutive equation using a modified version of the Eshelby's equivalent inclusion method combined with the gradient plasticity. We incorporated this macroscopic elastic-plastic constitutive equation into a finite element program and performed a homogenized finite element analysis of a particle-dispersed composite material in which both the macroscopic and microscopic behaviors More >

S. Ozaki¹, K. Hashiguchi², T. Okayasu², D.H. Chen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.18, No.2, pp. 101-120, 2007, DOI:10.3970/cmes.2007.018.101

Abstract In order to analyze precisely not only the elastoplastic deformation phenomenon of saturated particle assembly such as soils, grains, powdered and tablet medicines or three dimensional cellular materials, but also the frictional sliding phenomenon between saturated particle assembly and other bodies, a particle assembly-water coupled finite element program, that incorporates both the subloading surface and the subloading-friction models, is developed. Subsequently, simulations of the compaction behavior of saturated particle assembly under strain rate control are performed. It is revealed by the numerical experiment adopting the finite element program that the frictional sliding behavior of the contact boundary More >