考虑温度与围压的HTPB固体推进剂细观结构损伤演化机制OA北大核心CSTPCD

To investigate the influence of loading environment on the damage evolution mechanism of solid propellant,the me-sostructure of solid propellant under the different porosity and strain rates was studied by means of tensile test,SEM and micro-CT.The damage characteristics of propellants were quantitatively analyzed under different temperatures,confining pressures and strain rates.The results show that the maximum tensile strength and elongation of HTPB propellant increase significantly at high confining pressure(10 MPa).Under low temperature and high confining pressure(-45℃,10 MPa),"dewetting"damage is suppressed,which makes the interface bonding intimately between AP particles and matrix,and the microcracks are more likely to aggregate to form cavities,and then the particle breakage damage mechanism occurs.In the meso-deformation stage,cracks appear prior to reac-hing the maximum tensile strength on the stress-strain curve.In the macro-crack stage,only a small percentage of the pores exhibit high sphericity,while most of the pores are irrqular and low-sphericiyt damage crackes,accounting for approximately 75% .The re-lationship between damage pore diameter and sphericity conforms to power-law correlation,with a power-law index of-0.246.In the failure stage,the damage mechanism of propellant includes particle breakage,"dewetting"damage and matrix adhesion.