关键词: 镁合金, 高速冲击, 数值仿真, 弹道极限, 失效模式

Abstract: To investigate the impact resistance of AZ31B magnesium alloy, impact tests were firstly conducted on 5 mm thick magnesium alloy target plates using a one-stage light gas gun. Then, considering the tension-compression asymmetry of magnesium alloy, numerical simulation models related to the impact tests were constructed to vali鄄 date the effectiveness of the parameters of the modified Johnson-Cook (MJC) constitutive model and the modified Mohr-Coulomb (MMC) fracture criterion. Finally, the prediction accuracy of both the MJC tensile and compres鄄 sive constitutive models was evaluated. The results indicate that under high-velocity impact by a flat-nosed pro鄄 jectile, the target plate primarily undergoes shear failure. Furthermore, the MJC constitutive model and the MMC fracture criterion fitted by the tensile tests can more accurately predict the deformation and failure behavior of the magnesium alloy target plate, demonstrating superior prediction accuracy. This study can provide experimental evidence and theoretical reference for the design of impact-resistant structures and numerical simulation model鄄 ing of magnesium alloys in the aerospace field.

Key words: magnesium alloy, high-velocity impact, numerical simulation, ballistic limit, failure mode