塑性成型弹塑性有限元模拟的静水压力间接计算法

在单元内偏应力导数精度分析的基础上，了偏应力导数佳点逐层积分建立了修正的静水压力间接算法，将该方法应用于金属成型过程的弹塑性有限元模拟中，较好了解决了大步长时应力计算精度低的问题，提高了计算效率，算例表明，在变形总量和应变步长都较大的情况下。用庐方法计算得到的应力和变形载荷仍具有较好的精度。

AN INDIRECT CALCULATION METHOD OF HYDROSTATIC STRESS FOR ELASTO PLASTIC FINITE ELEMENT SIMULATION OF PLASTIC FORMING

Based on the accuracy analysis of deviatoric stress derivatives in an element, this paper presents a concept of superaccuracy location of deviatoric stress derivative, and, by introducing this concept as well as layer by layer integration, establishes a modified method for indirect calculation of hydrostatic stress. The application of the method in the elasto plastic finite element simulation of metal forming process considerably improves the accuracy of stress for the case in which large increments are used, and raises the calculated efficiency. Numerical tests show that the deformation loads predicted by this method are in good precision even when both the deformation increments and total deformation amounts are large.