Parameter Inverse Identification and Damage Failure Process Simulation of Adhesive Interface of Solid Rocket Motor

In order to study the damage and failure process of adhesive interface of solid rocket motor, rectangular adhesive specimen of solid rocket motor was made based on QJ2038.1A-2004 regulation standard and tensile tests was carried out. The damage and failure mode of the adhesive interface specimen was obtained. The parameter inverse identification method which is based on step inverse and Hooke-Jevees optimization algorithm was adopted. The relevant parameters of the bilinear cohesive model of mix mode at the propellant/liner/insulator interface were obtained and were applied into the numerical simulation of the damage and failure process of adhesive specimen in tensile tests. Results show that the main failure form of adhesive interface specimen is the debonding at the interface of the propellant/liner/insulator layer; the proposed parameter inverse identification method can obtain the interface parameters of solid rocket motors well. The initial modulus, maximum bonding strength and fracture energy of the propellant/liner/insulator layer of solid rocket motors are 0.86 MPa, 0.63 MPa and 3.13 kJ•m-2 at tension speed of 2 mm•min-1, respectively. The damage of the propellant/liner/insulation layer interface makes the increase rate of stress decrease with the tensile strain. The initiation interface crack at the tip of the artificial debonding layer and the expansion along the center of the specimen, and finally penetration of the bonded specimen is the main damage and failure mode of the adhesive specimen. © 2021, Editorial Board of Chinese Journal of Energetic Materials. All right reserved.