材料Johnson-Cook破坏准则参数对侵彻行为的影响及校正

Influence of material parameters in Johnson-Cook fracture criterion on penetration depth and optimization for them

利用Johnson-Cook破坏模型和非线性商业软件Abaqus,以4340钢杆弹垂直侵彻半无限4340钢靶板为例,探讨和分析参数D1D5对破坏等效应变及侵彻计算过程与结果的影响,并获得各参数对侵彻深度的影响规律。研究表明:参数D1的取值为正值且应非常接近于0.000,综合考虑计算的稳定性,金属材料可取0.001或稍小;D4可取负值,建议为[-0.005,0.005];弹体在侵彻过程中接触部位所受静水压力为正（以压为正）且数值较大,入射速度为2.47 km/s时,弹体头部最大压力-等效应力比最大,达到142.14;D2和D3的取值应非常谨慎,需要通过数值计算验证。用所给出的校正方法和原则,对4340钢的Johnson-Cook破坏准则中参数进行校正,认为参数D1D5分别可取为0.001、2.730、2.000、0.002和0.610,数值计算表明,用该组数据进行数值计算的结果与实验接近,侵彻仿真过程合理准确。

Based on the test data in published literatures,the numerical simulations of long rod projectile vertically penetrating semi-infinite 4340 target were conducted using Abaqus and Johnson-Ccook fracture model. The influences of parameters D1-D5 on the equivalent plastic strain in fracture and on the penetration results were studied and discussed. The influence rules of these parameters on the maximal penetration depth were investigated. The results indicate that the value of D1 should be non-negative and very close to 0.000,but it can be set to 0.001 if the stability of numerical computation is concerned;the value of D4 ranges from-0.005 to 0.005;the values of pressure/equivalent stress in the contact region between projectile and target in the process of penetration are positive and very large. For example,the maximal value reaches 142.14 when the incident velocity is 2.47 km/s.So the values of D2 and D3are the most important parameters and should be testified using numerical simulation or experiments.Finally,the revised data of D1- D5 were proposed(0.001,2.730,2.000,0.002 and 0.610,respectively). Comparison of simulation results with test results shows that the revised data are validated to be reasonable and accurate.