基于粘聚区模型的推进剂开裂数值仿真

为了研究复合固体推进剂裂纹开裂过程,利用粘聚区模型理论构建了复合固体推进剂断裂过程的物理和数学模型;推导了粘聚区单元的有限元离散格式;结合ABAQUS二次开发技术对裂纹扩展过程进行了数值仿真,获得了HTPB推进剂Ⅰ-Ⅱ型裂纹扩展过程中的裂纹扩展路径和裂尖应力变化情况.分析了粘聚区本构参数对仿真结果的影响,确定了其取值范围.将仿真和实验对比,结果表明所建立的数值仿真方法可以较为准确地模拟复合固体推进剂裂尖的损伤应力场,以及预测裂纹扩展路径;粘聚区模型可以为固体推进剂装药完整性和安全性分析提供可靠的分析计算方法.

Numerical Simulation of Crack Propagation in Solid Propellant Based on Cohesive Zone Model

To investigate the crack propagation in Composite Solid Propellant(CSP),the cohesive zone model was used to establish physical and mathematical model for the fracture process of CSP,and the cohesive element formulation was derived.Numerical simulation of crack propagation was carried out by using ABAQUS second development technology.The crack path and stress changes of crack tip in HTPB propellant containing Ⅰ-Ⅱ mixed mode crack were obtained.The influence of cohesive zone constitutive parameter on simulation results was analyzed to determine its scope.The numerical simulation result was compared with experimental result.The results show that by the developed numerical simulation method,the damage stress field of crack tip of CSP can be accuratelly simulated and the crack propagation can be predicted.The cohesive zone model offers analysis method for analyzing the integrality and safety of propellant grain.