固体推进剂/衬层界面裂纹的界面层模型有限元分析

摘要

A finite element interfacial zone model was developed for the solid propellant/liner interface crack. In the model, the interfacial zone was divided into three regions with the initial elastic modulus of each region varying in special functions. The software ABAQUS was used to mesh the model and the user subroutine USDFLD was employed to define the initial modulus of the graded material in the interfacial zone. The stress and strain fields and stress intensity factors were obtained when the crack was subjected to normal and shear displacements. The results show that when the storage time of the interface increases, the whole stress near the crack tip and stress intensity factors decrease significantly while the max. value of the strain increases slightly. Besides, the new model and the results have the engineering significance for the solid propellant/liner interface crack problem.%建立了固体推进剂/衬层界面裂纹的界面层有限元模型,该模型将界面层划分成3个区域,每一区域内采用特定函数表示材料初始弹性模量的分布.应用软件ABAQUS划分网格并采用子程序USDFLD定义界面层内梯度材料的初始模量,计算得到了法向和剪切位移加载下的应力应变场和应力强度因子.计算结果表明,界面贮存时间延长时,裂纹尖端附近整体应力及应力强度因子明显减小,而应变最大值略有增大.该模型的建立及计算结果对求解固体推进剂/衬层界面裂纹问题有一定的工程意义.