A novel time dependent cohesive zone model for the debonding interface between solid propellant and insulation

A novel time dependent cohesive zone model (CZM) is proposed in this paper based on two main assumptions. Firstly, ultimate cohesive parameters are inherent and fixed for a given non-aging bond interface. The apparent cohesive parameters are time related variables. Secondly, relaxation response of the interface is the main reason for the time dependent traction. Numerical simulation shows that the traction, critical displacement as well as damage initiation displacement will increase with imposed loading rate and parameter λ for single Maxwell box based model. N single Maxwell box connected in parallel construct the N Maxwell box based model, and each Maxwell box bears 1/N traction of the interface. Double cantilever beam (DCB) is utilized to investigate the structure response with the single Maxwell box based model including constant stretch and relaxation test. Quite good agreement between the numerical and experimental reaction force–displacement curves is obtained from stretch test of Double cantilever sandwich beam (DCSB) specimen with four different N Maxwell box based model, especially when the number of the Maxwell box is 7. It is a fact that the model will be more adaptive with more Maxwell box connected in parallel which can be revealed by the verification test.