确定结构分支点及跟踪平衡路径的改进弧长法

Improved Arc-length Method for Detecting Bifurcation Points and Tracing Buckling Equilibrium Path of Structures

在非线性有限元法的基础上，提出了一个新的搜索及确定结构非线性分支点并跟踪屈曲平衡路径全过程的求解方法─—改进弧长法.利用弧长控制多数和结构协线刚度矩阵特征值之间的非线性关系，建立了搜索并确定位于结构屈曲平街路往任一区段内的分支点的精确分析方法.改进弧长法已用于薄壳结构的非线性屈曲分析之中，数值结果表明了新方法的精确性、可靠性及计算效率.

Based on the nonlinear finite element method, a new techniqu-an improved arc-length method, is established for detecting the critical points and tracing the buckling equilibrium path of structures. Using the nonlinear relation between the arc-length parameter and the stiffness matrix of the structures, the conventional arc-length method is improved. The method has been used to analyze the thin shell structures. Numerical results show that the new method is accurate, reliable and efficient.