V. Vavourakis ¹

CMES-Computer Modeling in Engineering & Sciences, Vol.36, No.2, pp. 119-146, 2008, DOI:10.3970/cmes.2008.036.119

Abstract In this paper, a new meshless Local Hypersingular Boundary Integral Equation method is presented for the analysis of two-dimensional elastostatic problems. The elastic domain is discretized by placing arbitrarily nodes on its boundary and interior. Given this set of nodes, the corresponding map of background triangles is constructed through a common triangulation algorithm. The local domain of each node consists of the union of triangles that this point lies, thus, creating a polygonal line of its local boundary. The local boundary integral equations of both displacements and stresses of the conventional Boundary Elements Method are taken into account. The interpolation… More >

S. Wong, Y. Shie

CMES-Computer Modeling in Engineering & Sciences, Vol.36, No.2, pp. 97-118, 2008, DOI:10.3970/cmes.2008.036.097

Abstract In this paper, we propose a Galerkin-based smoothed particle hydrodynamics (SPH) formulation with moving least-squares meshless approximation, applied to solid mechanics and large deformation. Our method is truly meshless and based on Lagrangian kernel formulation and stabilized nodal integration. The performance of the methodology proposed is tested through various simulations, demonstrating the attractive ability of particle methods to handle severe distortions and complex phenomena. More >

H. Nguyen-Van¹, N.Mai-Duy¹, T. Tran-Cong¹

CMES-Computer Modeling in Engineering & Sciences, Vol.36, No.1, pp. 65-96, 2008, DOI:10.3970/cmes.2008.036.065

Abstract A novel node-based smoothing element for triangular and quadrilateral meshes is presented for static analysis of planar piezoelectric structures. In contrast to the smoothed finite element formulation that was based on sub-cells within an original quadrilateral element, this new method transforms a general original finite element mesh into a mesh of new smoothing cells individually associated with a single node which is termed as node-based elements. The displacement fields of the element are approximated by the linear interpolation functions of the original mesh while the approximations of mechanical strains and electric potential fields are normalized using the stabilized conforming nodal… More >

H.X. Wang, S.X. Wang

CMES-Computer Modeling in Engineering & Sciences, Vol.35, No.3, pp. 253-274, 2008, DOI:10.3970/cmes.2008.035.253

Abstract In the meshfree cohesive crack method, the discrete crack is modeled by a set of cohesive crack segments which can be arbitrarily oriented. Propagation of the crack is achieved by activation of crack surfaces at individual nodes, so no representation of the crack surface is needed. The crack is modeled by a local enrichment of the test and trial functions with sign function, so that discontinuities are along the direction of the crack. A set of cracking rules is developed to avoid spurious cracking. More >

C.E. Majorana¹, V.A. Salomoni

CMES-Computer Modeling in Engineering & Sciences, Vol.33, No.1, pp. 49-84, 2008, DOI:10.3970/cmes.2008.033.049

Abstract A dynamic analysis of a thin shell finite element undergoing large displacements and rotations is here presented. The constitutive model adopted derives from the coupling of an hyperelastic basic model fulfilling a De Saint Venant-Kirchhoff criterion with a scalar damage function depending on the maximum value of a suitable strain measure attained through the deformation history; then plastic effects are included using an isotropic/kinematic hardening law. A conservative time integration scheme for the non-linear dynamics of the hyperelastic damaged-plastic thin shell is applied. The main characteristic of the scheme is to be conservative, since it allows for the time-discrete system… More >

A.N. Guz¹, J.J.Rushchitsky¹, I.A.Guz²

CMES-Computer Modeling in Engineering & Sciences, Vol.26, No.3, pp. 139-156, 2008, DOI:10.3970/cmes.2008.026.139

Abstract The basic approach is offered for problems of nanocomposites and their mechanical properties, which includes a short review of modern problems in nanomechanics of materials. The fibrous carbon-polymer composites with carbon or graphite microfibers or carbon nanotubes are especially discussed. The basic model of the linear or nonlinear elastically deforming micro- and nanocomposites is considered. Within the framework of this model, the comparative computer modeling is performed. The modeling permits to observe the features in prediction of values of basic mechanical constants. These results are utilized on next step of modeling -- studying the peculiarities of wave propagation in particular… More >

K.G. Vinod¹, S. Gopalakrishnan¹, R. Ganguli¹

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.3, pp. 197-208, 2006, DOI:10.3970/cmes.2006.016.197

Abstract A spectral finite element formulation for a rotating beam subjected to small duration impact is presented in this paper. The spatial variation in centrifugal force is modeled in an average sense. Spectrum and dispersion plots are obtained as a function of rotating speed. It is shown that the flexural wave tends to behave non-dispersively at very high rotation speeds. The numerical results are simulated for two rotating waveguides of different dimensions. The results show that there is a steep increase in responses with the response peaks and the reflected signals almost vanishing at higher rotating speeds. The solution obtained in… More >

J. X. Zhou¹, T. Koziara¹, T. G. Davies¹

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.2, pp. 131-140, 2006, DOI:10.3970/cmes.2006.016.131

Abstract The classical BEM approach for elastodynamics can produce poor results when high gradients are generated by impulses. High gradient areas evolve over time and their locations are unknown a priori, so they usually can not be captured by uniform meshes. In this paper, we propose a novel method which interpolates both spatial and temporal domains. A direct space-time discretization scheme is used to capture the wave fronts accurately and to forestall generation of spurious oscillations there. Some numerical examples are given to demonstrate the power and scope of the method. More >

Jin Ma, Yang Liu, Hongbing Lu, Ranga Komanduri¹

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.1, pp. 41-56, 2006, DOI:10.3970/cmes.2006.016.041

Abstract A multiscale simulation technique coupling three scales, namely, the molecular dynamics (MD) at the atomistic scale, the discrete dislocations at the meso scale and the generalized interpolation material point (GIMP) method at the continuum scale is presented. Discrete dislocations are first coupled with GIMP using the principle of superposition (van der Giessen and Needleman (1995)). A detection band seeded in the MD region is used to pass the dislocations to and from the MD simulations (Shilkrot, Miller and Curtin (2004)). A common domain decomposition scheme for each of the three scales was implemented for parallel processing. Simulations of indentation were… More >

K.H. Chen¹, J.T. Chen², J.H. Kao³

CMES-Computer Modeling in Engineering & Sciences, Vol.16, No.1, pp. 27-40, 2006, DOI:10.3970/cmes.2006.016.027

Abstract In this paper, we employ the regularized meshless method (RMM) to search for eigenfrequency of two-dimension acoustics with multiply-connected domain. The solution is represented by using the double layer potentials. The source points can be located on the physical boundary not alike method of fundamental solutions (MFS) after using the proposed technique to regularize the singularity and hypersingularity of the kernel functions. The troublesome singularity in the MFS methods is desingularized and the diagonal terms of influence matrices are determined by employing the subtracting and adding-back technique. Spurious eigenvalues are filtered out by using singular value decomposition (SVD) updating term… More >