固 体 发 动 机 药 柱 低 温 点 火 开 裂 失 效 的 跨 尺 度 分 析

To accurately predict the cracking of propellant grain during ignition at low temperatures，a cross-scale analysis method coupled with global-local unidirectional contracting was proposed. For Nitrate Ester Plasticized Polyether（NEPE）propellant，uniaxial tensile tests at low temperature and intermediate strain rate were carried out，and the typical failure modes of the propellant were obtained. The results show that the ignition of solid rocket motor grain at low temperature can be analyzed successfully with macroscope method based on the developed nonlinear viscoelastic constitutive model，and the location of the dangerous point for propellant grain was obtained. Meanwhile，a mesoscopic particle filling model considering the particle-matrix interfacial debonding and particle fracture was established，and the analysis results on a macro scale were applied to the corresponding mesoscopic representative volume element（RVE）. Finally，based on the established mesoscopic failure criteria of the propellant，it is shown that the structural integrity of the propellant grain meets the requirements under low-temperature ignition conditions. Furthermore，the proposed contracting cross-scale analysis method can be used as an effective method to predict the cracking behaviors of the propellant grain during ignition at low temperature.