高温下TC4合金的黏塑性本构模型研究  

The viscoplastic constitutive model of TC4 alloy under high temperature

作　　者：何宇鑫 马玉娥[1] HE Yuxin;MA Yu′e(School of Aeronautics,Northwestern Polytechnical University,Xi′an 710072,China)

机构地区：[1]西北工业大学航空学院,陕西西安710072

出　　处：《西北工业大学学报》2023年第1期65-72,共8页Journal of Northwestern Polytechnical University

基　　金：国家自然科学基金(91860128)资助。

摘　　要：TC4合金广泛应用于高温环境下,基于TC4合金的单轴蠕变试验和高温拉伸试验研究了其高温下的黏塑性本构模型。提出一种不统一的考虑损伤的黏塑性本构模型,将非弹性应变分解为蠕变应变和塑性应变两部分,蠕变应变采用多轴延性耗竭模型计算,塑性应变通过考虑损伤和随动硬化的屈服函数计算,并推导了该模型的有限元隐式积分算法和一致切向模量。使用遗传算法确定了该模型所需的材料参数,通过Abaqus有限元软件的UMAT子程序将该模型进行编程并采用三维八节点等参单元进行计算。由计算结果可知,该模型可以有效地预测TC4合金蠕变曲线的3个阶段以及高温拉伸过程中的软化阶段。TC4 alloy is widely used in the high temperature environment.This paper proposed an ununified viscoplastic constitutive model according to the uniaxial creep experiment and high temperature tensile experiment of TC4 alloy.The inelastic strain rate was decomposed into two parts:creep strain rate and plastic strain rate.The creep strain was calculated by multiaxial ductility exhaustion creep damage law,and the plastic strain was get from the yield function containing the damage and the kinematic hardening effect.The implicit stress integration algorithm and the consistent tangent modulus of this model were derived.The material constants of the proposed model were determined by using genetic algorithm.The proposed constitutive model was compiled in a UMAT subroutine of finite element software Abaqus and 3D eight nodes isoparametric brick element was employed to simulate the creep and the tensile behavior of TC4 alloy.Form the result,the proposed constitutive model can predict the three stages of creep curves and the softening stage of tensile curves accurately.

关 键 词：TC4合金 蠕变 高温拉伸 黏塑性本构模型 隐式积分算法 

分 类 号：V252[一般工业技术—材料科学与工程]