Three-dimensional Numerical Study and Model Optimization of Motors Interface Mode I Failure

In order to study the application of cohesive zone model (CZM) in the bonding interface of solid rocket motors more accurately, the traditional two-dimensional cohesive zone model was extended to three-dimensional form. The mode I failure process of the bonding interface of the insulation/propellant of solid rocket motors was simulated by finite element technique, and the load-displacement curve was compared with that obtained by the test of double cantilever beam. It is found that the three-dimensional cohesive zone model fits the test results well, and can obtain the reaction force at the loading end more accurately than the two-dimensional model, so as to describe the failure process of the interface more accurately. By changing the thickness of propellant and insulation in DCB specimen, it is found that it has certain influence on load-displacement curve.