基于全域CZM的复合推进剂细观损伤与断裂研究

Research on microscopic damage and fracture of composite propellant based on global CZM

采用全域 CZM 模型模拟了复合固体推进剂从细观脱湿到基体开裂,直至微裂纹扩展汇合,最后断裂破坏的演化过程,探索了其宏观力学行为发生发展的内在原因。数值模拟结果在微裂纹的开裂特征以及推进剂的宏观应力应变曲线等方面与试验结果吻合较好。研究结果表明,采用全域 CZM 模型能有效模拟复合推进剂材料细观断裂破坏过程及其宏观力学性能;通过参数反演可知混合基体的初始刚度远小于颗粒/基体界面的,而粘接强度和粘接能大于界面的,这使得基体易变形而界面先脱湿;可将推进剂受拉伸载荷的细观力学行为分为四个阶段:无损伤变形阶段、界面部分脱湿阶段、脱湿与基体开裂并存阶段、微裂纹聚合断裂阶段。

The global CZM model has been used to simulate the evolution process of composite solid propellants from debonding to matrix damage,to microcrack propagation and convergence,and finally to explore the intrinsic causes of its macro mechanical be havior.The numerical simulation results are in good agreement with the experimental results in the cracking characteristics of micro cracks and macro stress strain curves of propellants.The results show that the global CZM model can effectively simulate the micro fracture process and macro mechanical properties of composite propellant materials.The initial stiffness of the mixed matrix is much smaller than that of the interface through parameter inversion,whereas the bonding strength and bonding strength are better.The mi cro mechanical behavior of solid propellant can be divided into four stages:non damage stage, partial debonding stage,co existence stage of debonding and matrix cracking stage,as well as the micro crack aggregation fracture stage.