HTPB推进剂粘聚区本构模型反演识别研究

Inversion Identification of Constitutive Model of Cohesive Zone in HTPB Propellant

端羟基聚丁二烯(HTPB)推进剂在拉伸过程中裂尖存在一个明显的非线性粘聚区,粘聚区本构模型的精度影响着推进剂装药裂纹起裂和扩展过程的数值仿真结果。为了准确地获得HT-PB推进剂的粘聚区本构模型,建立了基于实验的反演识别方法,该方法通过实验获取粘聚区断裂能和断裂强度参数,使用有限元模型更新方法得到粘聚区本构曲线形式参数。将获得的本构模型应用于裂纹起裂和扩展过程仿真,研究结果表明所建立的粘聚区本构参数获取方法简单可行;所获得的粘聚区本构参数可以准确地模拟出HTPB推进剂裂纹起裂和扩展过程。

There exists a nonlinear cohesive zone at the crack tip in stretching hydroxyl terminated poly- butadiene （HTPB） propellant, and the accuracy of its constitutive model can affect the fracture simula- tion greatly. In order to establish a precise constitutive model, an experiment-based inversion method was presented. The cohesive fracture energy and fracture strength were obtained experimentally, and the con- stitutive curve parameters of cohesive zone were determined by using the finite element model updating approach. The established constitutive model was applied to the crack initiation and propagation simula- tion. The results indicate that the presented method is simple and feasible, and it can predicate the crack initiation and propagation in HTPB propellant accurately.