基于区间参数摄动法的三维弹塑性区间有限元探讨

Discuss of 3D elastic-plastic problem basedon interval parameter pertubation analysis

首次探讨了弹塑性问题的区间分析,推导了三维弹塑性问题的区间参数摄动法有限元计算公式,研制了相应的弹塑性区间有限元程序,通过算例分析得到结论:(1)采用增量法对弹塑性问题进行区间分析时,增量位移离差随着增量位移均值的增大而增大。(2)单元高斯点应力没有达到屈服极限之前,高斯点的应力离差很小;当单元高斯点应力达到屈服极限之后,高斯点应力离差逐渐增大。(3)是否考虑塑性矩阵的应力分量为弹塑性参数的隐函数,对应力离差计算的影响较小。

Interval analysis method of elastic-plastic problem is discussed.The formula that is used to analysis the elastic-plastic problem’s interval parameter perturbation method is deduced.Developed the interval parameter perturbation method program of three-dimensional elastic-plastic problem.Some conclusions are obtained:(1)when analysis the elastic-plastic interval problem by the incremental method,the incremental displacement’s deviation is increasing with the incremental displacement’s average value;(2)when the gauss point’s stress is not yield,the gauss point’s stress deviation is small,or else,the gauss point’s stress deviation is gradual increasing;(3)whether considering the plastic matrix’s stress component is the elastic-plastic parameter’s implicit function or not,the influence of the stress deviation is small.