航空学报 > 1982, Vol. 3 Issue (2): 36-42

一种可行的有限元网格优化法

龚尧南   

  1. 北京航空学院
  • 收稿日期:1981-04-01 修回日期:1900-01-01 出版日期:1982-06-25 发布日期:1982-06-25

A FEASIBLE SIMPLIFIED METHOD FOR FINITE ELEMENT GRID OPTIMIZATION

Gong Yaonan   

  1. Beijing Institute of Aeronautics and Astronautics
  • Received:1981-04-01 Revised:1900-01-01 Online:1982-06-25 Published:1982-06-25

摘要: 在用有限元素法进行分析时的一个主要考虑是,对于某个特定问题,如何才能以尽可能少的计算工作量获得尽可能高的计算精确度,这就是在过去十年中迅速发展起来的有限元最优离散化问题,并已提出了不少优化准则和算法。本文的目的在于提出一项改善有限元离散化的有效方法,以避免现有方法中的一些困难和不足,即:既可以避免纯数学规划法中过于庞大的计算时间,又可以避免批处理方式的麻烦;它编制程序简便,也无需计算等高线的专用软件以及与计算机接口的图象显示设备。它从误差分析得到使离散化近乎最优的可行方向,再通过一维搜索得到近似于最优的离散化。数值例题表明,采用本文方法进行优化,得益是十分显著的。

Abstract: An important consideration encountered in the use of the finite element method is how a computational result can be obtained as accurate as possible with the least computation effort for a special problem, especially for a problem of singularity with the character of stress concentration. This is the problem of Optimum Finite Element Discretization developed during the recent decade. In this period a lot of optimization criteria and corresponding procedures were proposed. The purpose of the present paper is to suggest a new effective method for improving the finite element discretization which can avoid the difficulties and shortcomings encountered in a batch-mode operation and doesn't need the special software for computation of contour lines and computer graphic displays. After a relatively simple operation, the grid optimization can be performed by the aid of a feasible direction obtained via opti-mality criteria combined with the one-dimensional search techniques. The computational results of numerical examples presented show that in the best case from an even grid to an optimized grid a gain of the total potential energy was obtained, being equivalent to an increase in the number of degrees of freedom from 40 to 4900. It is obvious from tables and graphics presented that quite satisfactory results are obtainable, no matter whether the global or the local error is concerned.