高频空化冲击作用下HTPB固体推进剂的细观损伤机制OA北大核心CSTPCD

In order to study the thermal-mechanical coupling behaviors and mesoscale damage mechanism of HTPB solid propel-lants under high frequency cavitation impact,a three-dimensional full gradaed HTPB solid propellant mesoscale modeling was proposed considering the actual interface between particle and matrix.Different from the traditional meso-mechanical model in which virtual cohesive force interface element is embedded between particle/matrix interface,the thermo-mechanical coupling meso-mechanical model of solid propellant under the impact of cavitation microjet is further established.The breaking mecha-nism,damage mechanism,local stress strain and temperature distribution of solid propellant were analyzed.The results show that the AP particles break directly when the cavitating microjet acts on the AP particles.With the increase of impact degree,the interface layer between AP particles and HTPB matrix is fractured by impact.The maximum stress and strain values of solid propellant after cavitation microjet impact are 34.27MPa and 1.314,respectively.The stress wave transmission path change due to the obstruction of AP particles,Al particles,and interface phases.The maximum temperature value of the cavitation impact solid propellant process shows a gradually increasing trend due to the gradual accumulation of fracture energy,internal energy and friction energy.The maximum temperature value is 24.59 ℃.The solid propellant at a position far away from the cavitation microjet has no obvious temperature rise due to the low heat transfer coefficient.