非线性复合材料杂交应力有限元的有效迭代方法

AN EFFECTIVE ITERATIVE METHOD OF THE HYBRID STRESS FINITE ELEMENT FOR NONLINEAR COMPOSITE MATERIALS

推导了面内剪应力应变关系非线性的复合材料的杂交应力有限元列式,给出了位移迭代和应力迭代的策略和步骤.提出一种非线性应力场迭代格式的改进方案,不仅提高了收敛速度,而且克服了大载荷下简单迭代法循环迭代而无法收敛的关键问题,使得所提出的非线性杂交应力元方法几乎对任意大载荷都能够收敛.数值算例表明该方法是确实可行的.

The nonlinear hybrid stress finite elements are formulated for the composite materials in which the in-plane shear stress and strain obey a nonliner relationship. The detailed strategy and procedures for the iterations of displacement and stress fields are given. A scheme to improve the iterative method of the stress fields is presented to accelerate the iteration convergence and overcome the divergent problem in the simple stress iteration for large load. The nonlinear hybrid stress finite element method proposed is shown to be effective regardless of load levels through numerical examples.