双剪双参数强度准则硬化函数的探讨

Hardening function of two-parameter twin shear unified failure criterion

目前双剪强度理论在工程实际中得到了广泛的应用。基于双剪理论和相关流动法则,采用各向同性强化法则,选用等效塑性应变作为强化参数,从一致性条件出发,推导出双剪双参数强度准则本构模型硬化函数的显式表达式,并利用单轴加载试验数据得到硬化函数与硬化参数之间的微分关系,推导出考虑硬化的双剪双参数强度准则本构模型的弹塑性刚度矩阵,给出了求解双剪强度理论硬化函数的另一思路。通过工程算例验证,得出一些结论对实际计算具有一定的指导意义。

Twin shear theory is abroad applied to engineering practice presently; according to twin shear theory and related flow rule, the isotropy enhanced rule is adopted; and the equivalent plastic deformation is regarded as enhanced parameter; and then the explicit expression of twin shear two parameters theory unification elastoplastic constitutive model is deduced in terms of consistency condition. Besides, the differential coefficient relations between hardening function and hardening parameter are obtained through uniaxial load experiment data to simplify hardening function for one-dimensional, then its elastoplastic stiffness matrix is deduced to provide a new method for dividing hardening function of twin shear theory. Through an actual engineering example, the paper gets some conclusions and provides certain instruction for actual calculation.