变结点无界元和有限元耦合在三维弹塑性分析中的应用研究

The Study of Application on the Finite Element with Coupled the Unboundary Element With Variable Nodes in the Three Dimensiona1 Elastc-plastic Analysis

本文给出了较为灵活的三维变结点(8—12)无界元模型,研究了此种单元幅射边中结点的最优位置分布。本文对一有解析解的算例的分析表明:有限元和无界元的耦合使用,可较大幅度地提高精度和计算效率,并且当塑性区发展至无界元内时,计算结果仍然正确。

In this paper, the model of the unboundary element with variable nodes (8--12) in the three dimensiona1 elasto-plastic analysis is proposed and the optimum location of the middle node in the radiant edge of the unboundary element is studied. The analysis of the example, which has an analytic solution, shows that the application of the finite element coupled with the unboundary element may raise the accuracy and the efficiency of calculation obviously. The calculating result of proposed method is still corret when the plastic area stretches into the region of nnboundary elements.