【摘要】 Johnson-Cook动态模型是非常重要的材料模型,被广泛应用于冲击动力学数值模拟.通过准静态单轴拉伸和单轴扭转试验获得应变硬化函数中的参数,给出Johnson-Cook模型中热软化参数和应变强化参数的确定方法.采用最优化算法识别材料参数,算法上,在参数空间采用迭代求解,寻找最优点使得实验数据与模型预测之间的偏差最小.讨论了考虑绝热温升影响的JC模型参数m的确定方法.更多还原

【Abstract】 The dynamic Johnson-Cook constitutive model is widely used in numerical simulation of materials under dynamic loading. This model is very important in impact dynamics. The method of determining the parameters of heat softening and strain-strengthening in the Johnson-Cook model was proposed based on the strain-hardening parameters obtained from the material experiments including quasi-static uniaxial tension and uniaxial torsion. The material parameters were identified with the optimization algorithm, in which the parameter space was solved through iteration and the optimal point was found to minimize the difference between the model prediction and the experimental data. In the adiabatic heating case,the determination method of the Johnson-Cook model parameter m was demonstrated.更多还原