为校验Lode参数相关断裂准则的有效性,在一级轻气炮上开展了直径5.9 mm的6061-T6511H铝合金圆柱杆撞击刚性靶的Taylor试验,撞击速度范围为163.4 ～ 327.7 m/s,得到了镦粗和剪切开裂两种变形和断裂模式.为表征6061-T6511H铝合金的力学行为,开展了多应力状态、多温度下的材料性能测试,结合试验结果和有限元计算标定了修正的Johnson-Cook本构模型和修正的Johnson-Cook断裂准则及一种新近提出的Lode参数相关的断裂准则.最后,在ABAQUS/Explicit中建立了三维有限元模型,采用标定的Lode参数相关和无关的断裂准则开展了数值Taylor撞击试验.结果表明,Lode参数相关的断裂准则可对6061-T6511H铝合金Taylor杆的断裂行为给出合理预报,而Lode参数无关的断裂准则过高估计了材料的延性没能预报到相关断裂行为.%To examine the effectiveness of Lode parameter dependent fracture criterion,Taylor impact tests of 6061-T6511H aluminum alloy cylinder rods with the diameter of 5.9 mm in the impact velocity range of 163.4 ～327.7 m/s were conducted with a one-stage light gas gun,where two deformation and fracture modes,i.e.,mushroomingand shear cracking were identified.Material performance tests under various stress states and temperatures were conducted in order to characterize the mechanical behavior of 6061-T6511H aluminum alloy.Based on test results and the corresponding FE numerical computing ones,the modified Johnson-Cook constitutive model,the modified Johnson-Cook fracture criterion and a newly developed Lode parameter dependent fracture criterion were calibrated.Then,3 D finite element models were built in ABAQUS/Explicit,where the fracture criterion of Lode dependent/independent mentioned above was adopted respectively to simulate the Taylor impacts.Results showed that Lode parameter dependent fracture criterion can reasonably predict fracture behaviors of Taylor rods made with 6061-T6511H aluminum alloy,while Lode parameter independent fracture criterions over-estate the material ductility and can't predict the relevant fracture behaviors.
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