CMDB/EPDM包覆界面脱粘性能研究

Research on debonding property of CMDB / EPDM coating interface

为了研究固体火箭发动机改性双基(CMDB)推进剂与三元乙丙(EPDM)包覆层界面的脱粘性能,通过双悬臂梁(DCB)试件和粘接件单轴拉伸试件对界面性能进行试验研究,获取了界面的内聚能和内聚强度。同时,引入双线性内聚力模型对界面层单元进行描述,建立了界面裂纹开裂扩展计算模型。模型仿真曲线与试验曲线一致性较好,表明所建内聚力模型能够反映界面力学特性。对试验与仿真过程中的裂纹面开裂扩展过程进行了比较分析,发现二者变化趋势基本一致,误差范围在12.5%以内,验证了界面模型在描述裂纹面扩展方面的可靠性。

In order to investigate the debonding property of the interface between the CMDB propellant and EPDM inhibitor,an experiment was conducted by using the double cantilever beam（ DCB） specimen and bonding uniaxial tensile specimen,the cohesive energy and cohesive strength were obtained. Meanwhile,the bilinear cohesive zone model was employed to describe the property of the interface elements,and a computing model for simulating the crack propagation was built by finite element method. The simulation curve and experiment curve were compared. The result shows that the model has a high precision and can characterize the mechanical property of bonding interface well. The differences between the simulation and experiment of the crack propagation property were analyzed. It is found that the changing trends are accordant with each other and the tolerance is less than 12. 5%,which certificates that the model has a high reliability in describing the crack propagation property.