Xie Hanfei, Zhang Xiangrong, Miao Feichao, Jiang Tao, Zhu Yingzhong, Wu Xinxin, Zhou Lin
State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.
School of Chemical Engineering, Anhui University of Science and Technology, Huainan 232001, China.
Materials (Basel). 2022 Aug 27;15(17):5931. doi: 10.3390/ma15175931.
When describing the relation between the flow stress and plastic strain of a material under a wide range of strain rates and temperatures, the original Johnson-Cook model generally requires a complicated modification, resulting in a loss of simplicity and clear physical interpretation. In this paper, without modification, the original Johnson-Cook model was calibrated separately for the static and dynamic compression of a DNAN-based melt-cast explosive. The stress-strain curves for static and dynamic compression of this explosive were experimentally measured with a universal testing machine and a split-Hopkinson pressure bar, respectively. Based on the stress-strain curves, the flow stress vs. plastic strain data were extracted and used to calibrate the Johnson-Cook model. The calibration process is described. The parameters for the strain term, strain rate term, and temperature term were fitted sequentially. One set of model parameters was not able to fully describe the relationship between flow stress and plastic strain for both the static and dynamic compression of the DNAN-based melt-cast explosive. Two sets of model parameters were separately calibrated and compared for the static and dynamic compression of this explosive. The effects of the adiabatic temperature rise and the definition of the yield point on this calibration were also investigated.
在描述材料在宽应变率和温度范围内的流动应力与塑性应变之间的关系时，原始的约翰逊 - 库克模型通常需要进行复杂的修正，这导致其失去了简单性和清晰的物理解释。在本文中，未进行修正，针对基于二硝酰胺铵（DNAN）的熔铸炸药的静态和动态压缩分别对原始的约翰逊 - 库克模型进行了校准。使用万能试验机和分离式霍普金森压杆分别对该炸药的静态和动态压缩应力 - 应变曲线进行了实验测量。基于应力 - 应变曲线，提取了流动应力与塑性应变数据并用于校准约翰逊 - 库克模型。描述了校准过程。依次拟合了应变项、应变率项和温度项的参数。一组模型参数无法完全描述基于DNAN的熔铸炸药静态和动态压缩时流动应力与塑性应变之间的关系。针对该炸药的静态和动态压缩分别校准并比较了两组模型参数。还研究了绝热温升和屈服点定义对该校准的影响。
