弹塑性板壳结构非线性有限元分析

Nonlinear finite element analysis of elastic plastic shell structure

本文根据塑性流动理论的基本公式，由隐式积分导出了与路径无关的变量更新算法和一致切线模量。采用单元广义应力应变直接离散塑性流动定律，构造了杂交应力单元一致切线刚度矩阵的显式表达式，编制了结构有限元程序ＳＡＦＥ，数值算例表明：本文的计算方法和计算程序是正确可靠的，可用于弹塑性板壳结构的非线性分析，计算结构屈曲临界载荷和极限承载能力。

In this paper, a variable updated scheme independent of increment iteration path and a consistent elastoplastic tangent moduli are developed by implicitly integrating the simple flow theory of plasticity. A explicity formulation of hybrid stress element stiffness matrix is presented basing on the discretization of the plastic flow rule with generalized element stress and strain. The structural analysis finite element program (SAFE) is developed. The numerical examples show that the present algorithm and program is efficient and accurate. It can be used to analyze nonlinear behaviour of elastic plastic shell structure and predict the critical buckling load and plastic ultimate load of shell structure.