含裂纹 HTPB 推进剂断裂准则研究

摘要

The surface crack of the solid propellant influences the security of SRM ( SolidR-ocket Motor) seriously.The stress intensity factor and J-integral used for fracture toughness at present can not be applied to solid propellant directly.In order to obtain the fracture criterion of model-Ⅰcrack for HTPB propellant at medium and low strain rate, a fracture criterion based on strain is established through experi-ment and numerical simulation.The uniaxial tensile tests of standard and unilateral notched HTPB propel-lant samples are conducted to get material tensile strength, and the finite element method is employed to calculate the strain intensity factor.The results indicate that the fracture criterion based on strain in this study is more practical than that based on stress for HTPB propellant at medium and low strain rate.%固体推进剂装药的表面裂纹严重影响着发动机的工作安全性。现阶段广泛使用的应力强度因子、J积分等断裂韧性指标不能直接应用于复合推进剂装药。为了得到HTPB推进剂Ⅰ型裂纹在中低应变率下的断裂准则，本文使用试验和数值仿真方法建立了一种基于应变的断裂准则。准则建立过程中分别使用标准试样和单边裂纹试样进行单轴拉伸试验，结合有限元方法计算了裂纹前端的应变强度因子。结果显示对于HTPB推进剂在中低应变率下使用本文中基于应变的断裂准则比基于应力的断裂准则实用性更强。