A novel approach for modeling liner interface debonding in solid rocket motors

In solid rocket motors, liner is applied into case/insulation and propellant interface to ensure the bonding of the propellant. Debonding occurring at the liner interface may lead to failure of the motor. The aim of this study is to develop a new approach for modeling liner interface debonding with cohesive zone model and to examine the usage of peel test for the fracture energy input of the model. To develop a cohesive zone model, peel tests and bond in tension tests are conducted. Liner’s fracture energy is calculated via outputs of the peel tests and energy equations. Finite element analysis of the peel test is performed with the developed bilinear cohesive zone model. Agreement is achieved between the numerical and test results without any inverse analysis. Therefore, the developed approach can be utilized to build cohesive zone models for liners without a costly iterative procedure.