H.H. Luo¹, Z.H. Tan^1,2, X. Han¹, C. Chen¹

CMC-Computers, Materials & Continua, Vol.32, No.1, pp. 1-14, 2012, DOI:10.3970/cmc.2012.032.001

Abstract The dynamic properties of aluminium alloy foam were investigated by using split Hopkinson pressure bar (SHPB) with diameter of 40 mm. The aluminium alloy pressure bar and pulse shape technique were used to modify the traditional SHPB due to the low impedance of aluminium alloy foam. Wave dispersion correction on the aluminium alloy pressure bar was studied by Fourier series. And the finite element numerical simulation was also performed to demonstrate and validate the dispersion correction results by Fourier series method. The reflected and transmitted wave measured in SHPB experiments were corrected by the backward More >

A.B. Tatomir^1,2, A.Szymkiewicz³, H. Class¹, R. Helmig¹

CMES-Computer Modeling in Engineering & Sciences, Vol.77, No.2, pp. 81-112, 2011, DOI:10.3970/cmes.2011.077.081

Abstract We present a two phase flow conceptual model, the corresponding simulator (2pMINC) and a workflow for large-scale fractured reservoirs, based on a continuum fracture approach which uses the multiple interacting continua (MINC) method complemented with an improved upscaling technique. The complex transient behavior of the flow processes in fractured porous media is captured by subgridding the coarse blocks in nested volume elements which have effective properties calculated from the detailed representation of the fracture system. In this way, we keep a physically based approach, preserve the accuracy of the model, avoid the common use of… More >

T.N. Killian¹, S.M. Rao¹ and M.E. Baginski¹

CMES-Computer Modeling in Engineering & Sciences, Vol.46, No.3, pp. 255-270, 2009, DOI:10.3970/cmes.2009.046.255

Abstract In this work, we present a new method of moments solution procedure for calculating acoustic/electromagnetic scattering and radiation by a metallic body whose physical dimension is very large with respect to wavelength. The specially computed basis functions and the testing procedure results in a block-diagonally-dominant moment matrix where each block along the diagonal corresponds to a portion of the structure. The new solution procedure results in considerable savings in terms of computer storage and processing times. Although the procedure is outlined in general mathematical terms, the numerical results are presented only for electromagnetic scattering from More >

S. Itoh¹, K. Taguchi¹, Y. Umemoto¹, H. Serizawa¹, H. Murakawa¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.5, No.2, pp. 47-54, 2008, DOI:10.3970/icces.2008.005.047

Abstract The authors have proposed Fractal and Hierarchical Multi-Grid Methods for solving ultra large FE problems [1, 2]. In these methods, the domain to be analyzed is subdivided into multi-grid which has fractal or hierarchical structure and the solution is obtained by solving equations for small cells or nodes at each hierarchy successively. In this research, potential capability of a Hierarchical Multi-Grid method is examined through simple example problems. More >

Haitao Wang¹, Zhenhan Yao¹

CMES-Computer Modeling in Engineering & Sciences, Vol.7, No.1, pp. 85-96, 2005, DOI:10.3970/cmes.2005.007.085

Abstract This paper addresses a new boundary element method (BEM) for the numerical analysis of mechanical properties in 3D particle-reinforced composites. The BEM is accelerated by a new version fast multipole method (FMM) in order to perform large scale simulation of a representative volume element (RVE) containing up to several hundred randomly distributed elastic spherical particles on only one personal computer. The maximum number of degrees of freedom (DOF) reaches more than 300,000. Efficiency of the developed new version fast multipole BEM code is evaluated compared with other conventional solutions for BEM. The effects of micro-structural More >

T. Furumura¹, L. Chen²

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.2, pp. 153-168, 2004, DOI:10.3970/cmes.2004.006.153

Abstract Recent developments of the Earth Simulator, a high-performance parallel computer, has made it possible to realize realistic 3D simulations of seismic wave propagations on a regional scale including higher frequencies. Paralleling this development, the deployment of dense networks of strong ground motion instruments in Japan (K-NET and KiK-net) has now made it possible to directly visualize regional seismic wave propagation during large earthquakes. Our group has developed an efficient parallel finite difference method (FDM) code for modeling the seismic wavefield and a 3D visualization technique, both suitable for implementation on the Earth Simulator. Large-scale 3D… More >

S.Aoki¹, K.Amaya², M.Urago³, A.Nakayama⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.6, No.2, pp. 123-132, 2004, DOI:10.3970/cmes.2004.006.123

Abstract The Fast Multipole Boundary Element Method(FMBEM) which is suitable for a large scale computation is applied to corrosion analysis. Many techniques of the FMBEM on the potential problems can be usefully employed. Additionally, some procedures are developed for corrosion analysis. To cope with the non-linearity due to the polarization curve, the Bi-CGSTAB iterative method which is commonly used in the FMBEM is modified. To solve infinite domain problems, the M₀⁰ which is obtained naturally in the multipole expansion is conveniently used. A pipe element for the FMBEM is developed. A couple of example problems are More >

O. Hassan¹, K. Morgan, J. Jones, B. Larwood, N. P. Weatherill

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.5, pp. 383-394, 2004, DOI:10.3970/cmes.2004.005.383

Abstract A numerical procedure for the simulation of 3D problems involving the scattering of electromagnetic waves is presented. As practical problems of interest in this area often involve domains of complex geometrical shape, an unstructured mesh based method is adopted. The solution algorithm employs an explicit finite element procedure for the solution of Maxwell's curl equations in the time domain using unstructured tetrahedral meshes. A PML absorbing layer is added at the artificial far field boundary that is created by the truncation of the physical domain prior to the numerical solution. The complete solution procedure is More >

W.C. Chew¹, J.M. Song¹, T.J. Cui¹, S. Velamparambil¹, M.L. Hastriter¹, B. Hu¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.4, pp. 361-372, 2004, DOI:10.3970/cmes.2004.005.361

Abstract This paper reviews recent advances in large-scale computational electromagnetics using frequency domain integral equations. It gives a brief history of methods to solve Maxwell's equations, followed by a description of various historical ages in solution technique developments. Then it describes computational electromagnetics followed by a brief description of how fast integral equation solvers such as the multilevel fast multipole algorithm (MLFMA) is constructed using the tree network. Some examples of large scale computing using MLFMA are given. Ray physics used to further accelerate the speed of MLFMA. The parallel implementation of MLFMA in a code More >