In order to build up a rate-dependent cohesive zone model (CZM) of the interface between hydroxyl-terminated polybutadiene(HTPB) propellant and insulation

experimental method and inverse analysis were adopted. Improved single lap joints (SLJ) specimens were used to conduct the HTPB propellant and insulation interface debonding experiment

then a numerical analysis was conducted with cohesive elements method

and with an inverse program developed based on Hook-Jeeves optimizing algorithm

the inverse analysis was conducted for the SLJ specimens to calibrate the interface parameters in different loading rates. Considering the significant rate-dependency shown in the parameters

a rate-dependent damage function was built and then the rate-dependent interfacial type Ⅱ CZM of HTPB propellant and insulation was built based on the bilinear CZM. The correlation coefficient between the predicted result and the experimental result is bigger than 99%

illustrating the rate-dependent CZM referred herein can accurately describe the fracture properties of propellant and insulation interface for the loading rate of 5mm/min to 200mm/min.