sábado, 10 de octubre de 2009

On new iterative method for solving systems of nonlinear equations





Non-linear dynamic analyses by meshless local Petrov-Galerkin formulations


In this work, meshless methods based on the local Petrov-Galerkin approach are proposed for the solution of dynamic problems considering elastic and elastoplastic materials. Formulations adopting the Heaviside step function and the Gaussian weight function as the test functions in the local weak form are considered. The moving least-square method is used for the approximation of physical quantities in the local integral equations. After spatial discretization is carried out, a non-linear system of ordinary differential equations of second order is obtained. This system is solved by Newmark/Newton-Raphson techniques. At the end of the paper numerical results are presented, illustrating the potentialities of the proposed methodologies. Copyright © 2009 John Wiley & Sons, Ltd.



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Original source : http://dx.doi.org/10.1002%2Fnme.2756...

Accurate and efficient simulation of transport in multidimensional flow


A new numerical method to obtain high-order approximations of the solution of the linear advection equation in multidimensional problems is presented. The proposed conservative formulation is explicit and based on a single updating step. Piecewise polynomial spatial discretization using Legendre polynomials provides the required spatial accuracy. The updating scheme is built from the functional approximation of the exact solution of the advection equation and a direct evaluation of the resulting integrals. The numerical details for the schemes in one and two spatial dimensions are provided and validated using a set of numerical experiments. Test cases have been oriented to the convergence and the computational efficiency analysis of the schemes. Copyright © 2009 John Wiley & Sons, Ltd.



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Published by xFruits
Original source : http://dx.doi.org/10.1002%2Ffld.2189...