基于细观参数的HTPB推进剂粘接界面损伤演化数值模拟

Numerical Simulation of Bonding Interface Damage Evolution of HTPB Propellant Based on Mesoscopic Parameters

为了研究加载角度对三组元端羟基聚丁二烯(HTPB)推进剂粘接界面细观失效机理的影响,使用微CT对单轴拉伸过程中的粘接界面进行原位扫描与重构,表征其损伤演化过程,然后将细观结构参数与损伤变量引入内聚力模型,得到不同加载角度下粘接界面的细观损伤演化过程。结果表明,粘接界面高氯酸铵(AP)颗粒的初始脱湿主要从靠近界面的弱界面层开始,方向沿界面的剪切分力方向。界面破坏形式与剪切角度有关,合力与界面的角度越小,裂纹越容易扩展至推进剂/衬层界面,反之裂纹扩展更容易发生在AP颗粒间。通过与CT试验结果对比,从失效模式与载荷位移关系验证了计算结果的准确性,揭示了不同加载角度下推进剂粘接界面结构的损伤演化规律。

In order to study the effect of loading Angle on the failure mechanism of HTPB propellant bonding interface,microCT was used to scan and reconstruct the bonding interface in⁃situ during uniaxial tensile process,and the damage evolution process was characterized.Then,the meso⁃structural parameters and damage variables were introduced into the cohesive force model,and the meso⁃damage evolution process of the adhesive interface under different loading angles was obtained.The results show that the initial dehumidification of AP particles at the bonding interface mainly starts from the weak interface layer near the inter⁃face,and the direction is along the shear component direction of the interface.The fracture pattern of the interface is related to the shear Angle.The smaller the resultant force and the Angle of the interface,the easier the crack propagation to the propellant/liner interface,whereas the crack propagation is more likely to occur between AP particles.Finally,compared with the experi⁃mental results,the accuracy of the calculated results is verified,and the damage evolution law of the propellant bonding inter⁃face structure under different loading angles is revealed.