Parallel Computation Of Finite Element With Hourglass Control For Impact Dynamic Problems

Impact widely exists in engineering, and the behavior of impact computation presents geometric and material non-linearity. Because Its complexity, the large-scale impact computing is very time-consuming. So its analysis is of great importance for both theoretical and engineering purpose. Doing some helpful contribution to this field is right the aim of the present paper.In order to simply and efficiently resolve the problem of large deformation, a 16-node shell element of relative degree of freedom has been developed in this paper for large deformation analysis of plate and shell structure. Without the rotation parameters, the displacement field of the shell element is represented by the displacement on the shell mid-surface together with the relative displacement on shell top surface. The development is based upon the complete three dimensional field equation of displacement, stress and strain. With the aid of Hu梂ashinzu variational principle and assumed strain method, a scheme to enhance the accuracy of the element for large displacement analysis is described. Resorting to Wilson抯 incompatible mode the assumed strain fields are constructed for the large deformation analysis. The finite element formulation of shell element of relative degree of freedom is derived. Numerical examples show that the proposed methodology achieves good performance for a range of problems which exhibit large deformation, elastic梡lastic dynamic response.For the purpose of reducing the computational costs of element force in large-scale impact computing, an efficient and accurate 8梟ode shell element with relative degrees of freedom, with hourglass control, was developed for linear and non-linear structural analyses. Hourglass control was provided to suppress spurious modes via the assumed strain method. An effective procedure to eliminate volumetric locking and shear locking was developed. Displacement and strain fields of the element are constructed. With the aid of Hu梂ashinzu variational principle and assumed strain method, the finite element formulation of shell element of relative degree of freedom is derived. Resorting to Wilson抯IIincompatible mode, the accuracy of the element is enhanced. Several numerical examples were presented to demonstrate the applicability of the proposed element for linear and non-linear analyses.Finally, based on domain decomposition method, a new mixed time integration parallel algorithm for structural dynamic analysis is presented and implemented on multi-processors cluster. The algorithm describes and studies the increase in speed which can be achieved by the implementation of subcycling in an explicit finite element parallel program executed on distributed memory MIMD computer. The program applies the usual message-passing parallelization technique based on the message-passing library PVM (parallel virtual machine). Finally, numerical examples show the efficiency of parallelization on the speed-up achieved with subcycling.