A. Rama Mohan Rao¹, T.V.S.R. Appa Rao², B. Dattaguru³

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.3, pp. 213-234, 2004, DOI:10.3970/cmes.2004.005.213

Abstract This paper presents an algorithm for automatic partitioning of unstructured meshes for parallel finite element computations employing float-encoded genetic algorithms (FEGA). The problem of mesh partitioning is represented in such a way that the number of variables considered in the genome (chromosome) construction is constant irrespective of the size of the problem. In order to accelerate the computational process, several acceleration techniques like constraining the search space, local improvement after initial global partitioning have been attempted. Finally, micro float-encoded genetic algorithms have been developed to accelerate the computational process. More >

B. Amaziane¹, A. Naji², D. Ouazar³

CMC-Computers, Materials & Continua, Vol.1, No.2, pp. 117-128, 2004, DOI:10.3970/cmc.2004.001.117

Abstract In this paper, a meshless method based on Radial Basis Functions (RBF) is coupled with genetic algorithms for parameter identification to some selected groundwater flow applications. The treated examples are generated by the diffusion equation with some specific boundary conditions describing the groundwater fluctuation in a leaky confined aquifer system near open tidal water. To select the best radial function interpolation and show the powerful of the method in comparison to domain based discretization methods, Multiquadric (MQ), Thin-Plate Spline (TPS) and Conical type functions are investigated and compared to finite difference results or analytical one. More >

E. Bleszynski¹, M. Bleszynski¹, T. Jaroszewicz¹

CMES-Computer Modeling in Engineering & Sciences, Vol.5, No.4, pp. 295-318, 2004, DOI:10.3970/cmes.2004.005.295

Abstract We describe elements of our current work on the development of new methods for high frequency electromagnetic scattering, based on the wavefront (WF) representation of propagating fields and on the asymptotic but rigorous solution of integral equations for surface currents. In the wavefront evolution technique, surfaces of constant phase are constructed and treated not merely as collections of independent rays, but as well defined geometrical objects endowed with the full connectivity information. Hence, a precise determination of shadow and reflection boundaries, a construction of (multiply) diffracted wavefronts, a dynamic adjustment of the number of rays,… More >

R. Mathur¹, S. G. Advani², B. K. Fink³

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.5, pp. 587-602, 2003, DOI:10.3970/cmes.2003.004.587

Abstract Real number-coded hybrid genetic algorithms for optimal design of resin injection locations for the resin transfer molding process are evaluated in this paper. Resin transfer molding (RTM) is widely used to manufacture composite parts with material and geometric complexities, especially in automotive and aerospace sectors. The sub-optimal location of the resin injection locations (gates) can leads to the formation of resin starved regions and require long mold fill times, thus affecting the part quality and increasing manufacturing costs. There is a need for automated design algorithms and software that can determine the best gate and… More >

L. Briseghella¹, C. Majorana¹, P. Pavan¹

CMES-Computer Modeling in Engineering & Sciences, Vol.4, No.2, pp. 273-286, 2003, DOI:10.3970/cmes.2003.004.273

Abstract Some aspects of the application of a conservative time integration scheme to the non-linear dynamics of elasto-damaged thin shells are presented. The main characteristic of the scheme is to be conservative, in the sense that it allows the time-discrete system to preserve the basic laws of continuum, namely the balance of the linear and angular momenta as well as the fulfilment of the second law of thermodynamic. Here the method is applied to thin shells under large displacements and rotations. The constitutive model adopted is built coupling the linear elastic model of De Saint Venant-Kirchhoff More >

José A. González, Ramón Abascal¹

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.3, pp. 141-150, 2000, DOI:10.3970/cmes.2000.001.443

Abstract In this work an approach to the two-dimensional steady-state rolling contact problem, with and without force transmission, is presented. The problem is solved by the combination of the Boundary Element Method with a formulation of the variational inequalities that govern the problem in the contact area, producing finally a mathematical programming problem. This formulation avoids the direct use of the contact constrains, but it drives to the minimisation of a non-differentiable function, being necessary the use of an specific numerical tool as the modified Newton's method. More >

R. Mustata¹, S. D. Harris², L. Elliott¹, D. Lesnic¹, D. B. Ingham¹

CMES-Computer Modeling in Engineering & Sciences, Vol.1, No.3, pp. 107-116, 2000, DOI:10.3970/cmes.2000.001.409

Abstract An inverse boundary element method is developed to characterise the components of the hydraulic conductivity tensor K of anisotropic materials. Surface measurements at exposed boundaries serve as additional input to a Genetic Algorithm (GA) using a modified least squares functional that minimises the difference between observed and BEM-predicted boundary pressure and/or hydraulic flux measurements under current hydraulic conductivity tensor component estimates. More >