结构非线性分析中改进的弧长算法

A Modified Arc-Length Method in the Nonlinear Static Structural Analysis

在原有的弧长增量法的基础上做了两方面的改进工作 :(1)提出一种新的弧长控制方法 ,消除了以往方法存在的漏洞 ;(2 )提出一种基于解曲线曲率的自动走步方案 ,使得整个的非线性追踪过程合理化。以上两点相结合形成一种新的改进的弧长法 ,该方法已经在PKPM弹塑性分析程序EPDA的子模块PUSH中加以实现 ,取得了良好效果。

In this paper, some improvements have been achieved with the arc length method. Firstly, a new strategy of arc length control has been presented to eliminate the defect existing in the old method. Secondly, an auto stepping method has been advanced, with which it will be more reasonable to trace the equilibrium path in the nonlinear structural static analysis. The combination of the two aspects mentioned above forms a new modified arc length method. The new method has been realized in a nonlinear static analysis program (EPDA PUSH) of PKPM CAD engineering department and the numerical tests show very good results.