In order to explore the nonlinear fatigue damage characteristics of nitrate ester plasticized polyether (NEPE) propellant

a nonlinear fatigue damage model was proposed based on damage mechanics and visco-elasticity theory

which took into account the stiffness degradation in the fatigue process. With dynamic momechanical analysis (DMA) apparatus

NEPE propellant fatigue tests were conducted under five kinds of strain levels

the model parameters were obtained and the presented model was verified. A morphology analyze was conducted with charge coupled device (CCD)

the effect of strain loading history on the mechanical properties of the NEPE propellant was analyzed. The result shows that the presented model is capable of describing micro-mechanically the nonlinear fatigue damage evolution of NEPE propellant properties; the repeated tensile leads to dewetting between the particles and matrix propellant. At the initial stage of the cycle phases

the velocity of dewetting is fast. With the increased number of cycles

the extent of dewetting tend to become stable.