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以铝青铜QAl9-4为试验材料,根据分离式霍普金森压杆试验得到的数据,研究了铝青铜在高速冲击载荷作用下的Johnson-Cook(J-C)本构关系,根据高应变率变形下,部分塑性功转变为微孔洞等微观缺陷长大演化所需能量的观点,提出了一个同时依赖于应变率和应变的损伤因子,在J-C模型的基础上建立了考虑损伤的改进型J-C模型,研究损伤对材料性能的影响。结果表明,当损伤因子小于阈值时,损伤造成的应力变化可忽略不计,此时,J-C模型与试验曲线比较吻合,当损伤因子大于该阈值时,改进的J-C模型更符合材料的动态破坏特性。本研究扩大了J-C模型的适用范围。
Based on the data obtained from the split Hopkinson pressure bar test, the Johnson-Cook (JC) constitutive model of aluminum bronze under high-speed impact loading was investigated using aluminum bronze QAl9-4 as a test material. According to the deformation under high strain rate , Some of the plastic work turns into the energy required for the growth of microscopic defects such as micropores, a damage factor that is dependent on both strain rate and strain is also proposed. Based on the JC model, an improved JC model considering damage , Study the impact of damage on the material properties. The results show that when the damage factor is less than the threshold, the stress changes caused by damage are negligible. In this case, the J-C model is in good agreement with the experimental curve. When the damage factor is greater than the threshold, the improved J-C model is more consistent with the dynamic failure characteristics of the material. This study expands the scope of the J-C model.