镁合金板材温热冲压过程的各向异性损伤与失效分析  

Anisotropic Damage and Failure Analysis of Magnesium Alloy Sheet Thermal Stamping

作　　者：蒋成钢[1] 陈章华[1] 臧勇[2] 

机构地区：[1]北京科技大学数理学院,北京100083 [2]北京科技大学机械工程学院,北京100083

出　　处：《机械工程学报》2013年第16期62-69,共8页Journal of Mechanical Engineering

基　　金：国家高技术研究发展计划资助项目(863计划;2008AA062104)

摘　　要：以连续损伤力学理论为基础,采用有限元数值模拟与试验结果进行对比的方法对镁合金板材的温热冲压成形中材料的损伤破坏情况进行预测。通过将各向异性屈服准则与各向异性损伤理论编入商业有限元软件ABAQUS的用户材料子程序VUMAT,模拟得到镁合金板材冲压成形过程中损伤量的演化规律。以冲压手机壳为例,针对板材的特性,提出将各向异性损伤张量转化为壳单元局部坐标系内损伤矢量的方法,有效表达不同区域失效情况。数值模拟结果表明,板材在不同温度下预测的断裂与失效结果与实际板材冲压试验的结果一致。因此,采用的各向异性损伤计算方法可以有效预测冲压过程中镁合金板材因各向异性损伤导致断裂失效的现象。Based on the frame work of the continuum damage mechanics,the prediction of damage evolution in a thermal stamping process of magnesium alloy sheet has been carried out by means of the finite element simulation,and the numerical results have been compared with the related experimental data.An anisotropic yield function for cold rolling sheet metals and an anisotropic damage theory are implemented into the ABAQUS user material subroutine VUMAT to predict the evolution of damage in the mentioned process.Taking a thermal stamping process of a phone shell for example,under the different working temperature,the overall anisotropic damage process from crack initiation to final propagation in local area of workpiece is proposed.Numerical results show that the prediction both of the site of crack initiation and the orientation of crack propagation are consistent with the data recorded in thermal stamping tests.It may be concluded that the proposed anisotropic damage model and the corresponding anisotropic yield function can be effectively incorporated into the finite element method（FEM） user material subroutine to predict the phenomenon of cracking during thermal stamping process of sheet metals.

关 键 词：镁合金板材 温热冲压 各向异性损伤 失效预测 数值模拟 

分 类 号：TG386[金属学及工艺—金属压力加工]