固化降温对复杂装药燃面退移过程中力学响应的影响研究

The mechanical performance of solid propellants plays a crucial role in the advancement of solid rocket motors. To explore the mechanical behavior of three-dimensional complex propellants during the burning surface regression process and investigate the impact of the curing cooling process on the mechanical performance of propellant grains，a comprehensive derivation of constitutive models for propellant grains in both stages was conducted. The coupling of burning surface regression with structural analysis was achieved using solid modeling methods. This approach leveraged the parametric modeling，preprocessing，and post-processing capabilities of commercial finite element software to capture the mechanical response of complex propellants under multiple coupling physical processes.The simulation results revealed that the stress and strain fields induced by the temperature decrease from the zero-stress temperature（75 ℃）to 20 ℃ in a specific type of solid rocket motor significantly influenced the mechanical response of the propellant grain during the burning surface regression process. The maximum stress increased by 93.2%，and the maximum strain increased by 83.5%. Despite an overall decreasing trend，the maximum values of stress and strain in the propellant grain exhibited instability during the burning surface regression process，influenced by the combined effects of internal ballistic performance and structural changes. The maximum stress and strain curves，when considering curing cooling，were respectively 58.8% and 65.2% higher on average compared to the curves without considering curing cooling. In general，the mechanical response of the propellant during the combustion process was found to be influenced by the topological structure of the burning surface. The impact of curing cooling results in stress and strain during the burning surface regression process consistently being higher than the scenario where curing cooling is not considered.