M. Patrício¹, R. Mattheij¹, G. de With²

CMES-Computer Modeling in Engineering & Sciences, Vol.41, No.1, pp. 69-94, 2009, DOI:10.3970/cmes.2009.041.069

Abstract In this paper the effect of the local structure of a highly heterogeneous composite material on the parameters that characterise crack propagation is analysed. The evaluation of stress intensity factors is discussed. A hybrid approach based on domain decomposition and homogenisation methods is employed to obtain accurate solutions with reduced computational complexity. 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 >

K. Lee¹, H. Park², S.W. Lee³

CMES-Computer Modeling in Engineering & Sciences, Vol.32, No.3, pp. 113-122, 2008, DOI:10.3970/cmes.2008.032.113

Abstract A post-processing scheme is presented to accurately determine transverse shear and normal stresses in composite panels undergoing geometrically nonlinear deformation under dynamic loading conditions. Transverse stresses are assumed through thickness at a point of interest and are recovered via a one-dimensional finite element method. The finite element method is based on the least square functional of the error in the equilibrium equation along the thickness direction and utilizes the in-plane stresses and resultant transverse shear forces per unit length obtained by a shell element analysis. Numerical results demonstrate that, with minimal addition of computational efforts, the present post-processing approach can… More >

O. Buzzi¹, D. M. Pedroso², A. Giacomini¹

CMES-Computer Modeling in Engineering & Sciences, Vol.31, No.2, pp. 85-106, 2008, DOI:10.3970/cmes.2008.031.085

Abstract The material point method (MPM) is a numerical method for the solution of problems in continuum mechanics, including situations of large deformations. A generalization (GMPM) of this method was introduced by Bardenhagen and Kober (2004) in order to avoid some computational instabilities inherent to the original method (MPM). This generalization leads to a method more akin of the Petrov-Galerkin procedure. Although it is possible to find in the literature examples of the deduction and applications of the MPM/GMPM to specific problems, its detailed implementation is yet to be presented. Therefore, this paper attempts to describe all steps required for the… More >

P.H. Wen¹, M.H. Aliabadi², Y.W. Liu³

CMES-Computer Modeling in Engineering & Sciences, Vol.30, No.3, pp. 133-148, 2008, DOI:10.3970/cmes.2008.030.133

Abstract Based on the variation of potential energy, the element-free Galerkin method (MFGM) has been investigated for structures with crack on the basis of radial base function interpolation. An enriched radial base function is introduced to capture the singularities of stress at the crack tips. The advantages of the finite element method are remained in this method and there is a significant improvement of accuracy, particularly for the crack problems of fracture mechanics. The applications of the element-free Galerkin method with enriched radial base function to two-dimensional fracture mechanics in functionally graded materials have been presented and comparisons have been made… More >

S. S. Chen¹, Y. H. Liu^1,2, Z. Z. Cen¹

CMES-Computer Modeling in Engineering & Sciences, Vol.28, No.1, pp. 39-56, 2008, DOI:10.3970/cmes.2008.028.039

Abstract In most engineering applications, solutions derived from the lower-bound theorem of plastic limit analysis are particularly valuable because they provide a safe estimate of the load that will cause plastic collapse. A solution procedure based on the meshless local Petrov-Galerkin (MLPG) method is proposed for lower-bound limit analysis. This is the first work for lower-bound limit analysis by this meshless local weak form method. In the construction of trial functions, the natural neighbour interpolation (NNI) is employed to simplify the treatment of the essential boundary conditions. The discretized limit analysis problem is solved numerically with the reduced-basis technique. The self-equilibrium… More >

Adan Vega¹, Sherif Rashed², Yoshihiko Tango³, Morinobu Ishiyama³, Hidekazu Murakawa²

CMES-Computer Modeling in Engineering & Sciences, Vol.28, No.1, pp. 1-14, 2008, DOI:10.3970/cmes.2008.028.001

Abstract Experimental observations have shown that the inherent deformation produced by multi-heating lines is not a simple addition of the inherent deformation produced by single heating lines. Therefore, to accurately predict inherent deformation, the method of superposing inherent deformation of single heating lines is not appropriate. To overcome this difficulty, the authors investigate the influence of multi-heating lines on line heating inherent deformation. First, the influence of previous heating lines on inherent deformation of overlapping, parallel and crossing heating lines is clarified. The influence of the proximity to plate side edge on inherent deformation is also taken into account in the… More >

Sarang Seyrafian¹, Behrouz Gatmiri², Asadollah Noorzad³

CMES-Computer Modeling in Engineering & Sciences, Vol.21, No.3, pp. 209-218, 2007, DOI:10.3970/cmes.2007.021.209

Abstract The vertical response of a rigid circular foundations resting on a continuously non-homogenous half space is studied analytically. The half space is considered as a liner-elastic media with a shear modulus increasing continuously with depth. The system of governing differential equations, based on the mentioned assumption, consist of two partial differential equations, is converted to ordinary equations' system by employing Hankel Integral transform. Using the method of extended power series (Frobenius Method) led to the general solution for the latter system. The mixed boundary problem is solved by introduction of functional expansion for the stress distribution under the foundation using… More >

A. Arockiarajan¹, A. Menzel²

CMES-Computer Modeling in Engineering & Sciences, Vol.20, No.1, pp. 55-72, 2007, DOI:10.3970/cmes.2007.020.055

Abstract To study rate-dependent properties of piezoelectric materials a micro-mechanically motivated model is applied in this work. The developed framework is embedded into a coupled three-dimensional finite element setting, whereby each element is assumed to represent one grain and, moreover, possesses a random initialisation of the underlying polarisation direction. Furthermore, an energy-based criterion is used for the initiation of the onset of domain switching and the subsequent propagation of domain wall motion during the switching process is modelled via a linear kinetics theory. The interaction between individual grains is thereby incorporated by means of a probabilistic approach -- a purely phenomenologically… More >

A. Arockiarajan¹, A. Menzel²

CMES-Computer Modeling in Engineering & Sciences, Vol.19, No.2, pp. 163-178, 2007, DOI:10.3970/cmes.2007.019.163

Abstract To study rate-dependent properties of piezoelectric materials a micro-mechanically motivated model is applied in this work. The developed framework is embedded into a coupled three-dimensional finite element setting, whereby each element is assumed to represent one grain and, moreover, possesses a random initialisation of the underlying polarisation direction. Furthermore, an energy-based criterion is used for the initiation of the onset of domain switching and the subsequent propagation of domain wall motion during the switching process is modelled via a linear kinetics theory. The interaction between individual grains is thereby incorporated by means of a probabilistic approach -- a purely phenomenologically… More >