基于损伤耦合粘塑性模型的AZ31B镁合金温变形行为研究  

Research on Warm Deformation Behavior of AZ31B Magnesium Alloy Based on Damage Coupled Viscoplastic Model

作　　者：赵江波 谢延敏[1] 刘程[1] 李伟 杜凌峰 杜美钰 冯凯 ZHAO Jiangbo;XIE Yanmin;LIU Cheng;LI Wei;DU Lingfeng;DU Meiyu;FENG Kai(School of Mechanical Engineering,Southwest Jiaotong University,Chengdu 610031,China)

机构地区：[1]西南交通大学机械工程学院,四川成都610031

出　　处：《热加工工艺》2024年第7期121-127,131,共8页Hot Working Technology

基　　金：四川省国际科技创新合作项目(2020YFH0078);机械结构优化及材料应用泸州市重点实验室项目(SCHYZSA-2204)。

摘　　要：为了准确描述AZ31B镁合金温变形中材料硬化、损伤和断裂行为,建立了基于位错密度的粘塑性模型与GTN损伤模型耦合的本构模型。在不同温度和应变率下对试样进行温拉伸试验,获得合金温变形下的应力-应变曲线。基于材料高温变形机理,以位错密度为内变量,建立粘塑性模型来描述材料的硬化行为,并采用智能算法来识别模型的材料参数。为描述材料温变形过程中的损伤演变,将GTN损伤模型与已建立的粘塑性模型进行耦合,建立温拉伸仿真有限元模型,利用Kriging代理模型结合智能算法反求损伤模型参数。最后,利用已建立的损伤耦合粘塑性模型分析温拉伸过程中的损伤演化和预测温胀形过程的破裂行为,并与试验结果进行对比。结果表明,该本构模型可以准确地预测AZ31B温变形过程中的损伤和断裂。In order to accurately describe the hardening,damage and fracture behavior of AZ31B magnesium alloy during warm deformation,a constitutive model based on the viscoplasticity model coupled with the GTN damage model was developed.Warm tensile tests were performed on the material samples at different temperatures and strain rates.Stress-strain curves under the thermal deformation of the alloy were obtained.Based on the material high-temperature deformation mechanism and taking the dislocation density as the internal variable,the viscoplastic model was established to describe the hardening behavior of the material,and the intelligent algorithm was used to identify the material parameters of the model.In order to describe the evolution of material damage during warm deformation,the GTN damage model was coupled with the established viscoplasticity model,a warm stretching simulation finite element model was established.The damage model parameters were reversed by using Kriging proxy model combined with intelligent algorithm.Finally,the established damage coupled viscoplastic model is used to analyze the damage evolution during warm tensile process and predict the fracture behavior of the warm bulge test,and compared with the experimental results.The results show that the constitutive model can accurately predict the damage and fracture of AZ31B during warm deformation.

关 键 词：AZ31B镁合金 温成形 位错密度 GTN模型 

分 类 号：TG301[金属学及工艺—金属压力加工] TG146.22[一般工业技术—材料科学与工程]