基于GTN损伤模型的塑性粘结炸药棘轮增长模拟

Ratchet Growth of PBX in Simulation Based on GTN Damage Model

基于GTN损伤模型对热循环下塑性粘结炸药(PBX)的不可逆变形进行研究时,由于该模型大多应用于韧性金属材料的损伤演化研究,因此需要通过研究各参数对计算结果的影响,开展GTN模型用于描述PBX在热循环中产生不可逆应变的适应性研究。对PBX炸药件进行-30~60℃的热循环处理,以炸药件柱面中间位置的应变为目标量,采用有限元分析软件Workbench中的多目标遗传算法对各参数进行多目标优化,得到基准参数集。逐一变化各参数,对比分析参数变化取值时基于GTN模型对不可逆膨胀规律描述的影响。结果表明:通过调节、优化初始屈服强度、硬化指数及各GTN模型参数值,GTN模型可以用来定量描述PBX在热循环加载下的不可逆膨胀规律。

The adaptability of PBX needs to be studied by analyzing the sensitivity of various parameters since Gurson-Tvergaard-Needleman(GTN)damage model is mostly used to study the damage evolution of ductile metal materials in the process of studying the irreversible transformation of PBX under thermal cycling.The thermal cycling test of PBX was carried out at the temperature from-30℃to 60℃.Taking the strain value in the middle of the explosive cylinder as a target value,the initial parameters were optimized by using the multi-objective genetic algorithm(MOGA)in finite element analysis software Workbench,and the reference values of parameters were obtained.The optimized parameters are changed separately,and their influences on the description of the irreversible expansion law are compared and analyzed based on GTN model.The results show that the GTN model can be used to quantitatively describe the irreversible expansion rule of PBX under thermal cycling by adjusting and optimizing the initial yield strength,the hardening exponent and the parameters of GTN model.