镁合金塑性-蠕变交互作用的损伤本构模型

Damage Constitutive Relationship of Coupled Plasticity-creep for Magnesium Alloy

基于简单机械模型并合理地定义广义时间标度,得到了描述塑性-蠕变交互作用的统一型本构方程.在此基础上,采用Gurson模型考虑了镁合金在铸造过程中及由二相粒子脱落等所造成的孔洞型损伤,建立了基于含球形孔洞的有限体积球体的损伤模型,由此建立了混合强化材料的损伤演化.利用所建立的描述损伤本构模型和损伤演化,分析了镁合金在循环载荷作用下的响应特性,取得了与实验相吻合的结果.

Based on a simple mechanical model and an appropriate definition of generalized time, a constitutive equation is obtained for coupled plasticity and creep behavior of materials. A damage evolution based on a spherical void model for mixed hardening materials is obtained by means of Gurson＇ s model. The damage evolution law is embedded in the adopted constitutive equation, and a damage constitutive equation is obtained for coupled plasticity and creep behavior of die - casting magnesium alloy. The response of magnesium alloy subjected to cyclic loads is analyzed. The validity of the Drowsed model is demonstrated by the satisfactory agreement between the experimental and calculated results.