结构非线性分析的变步长增量迭代法研究

A Study of Variable Step-length Incremental/Iterative Method for Nonlinear Structural Analysis

In this paper we make a deep study on variable step-length incremental/iterative method for nonlinear structural analysis. Simple explanations are given for constant step-length incremental/iterative method, single displacement controlling method and arc length controlling method from their geometric characteristics in load-deformation responses. Based on the mechanical concept, three new constraint.equations (i. e. zero incremental displacement norm, zero residual force norm and zero incremental work) are established for controlling iteration path. The automatic selection method of initial load increment is discussed. The reliability and efficiency of the afore-mentioned methods are studied through tracing snap through and snap back responses of two cylindrical shells.