A Micromechanics Model for Fatigue Life Prediction of Metal Matrix Composites

摘要

In this paper, a cumulative damage model is described to predict the fatigue lift of unidirectional metla matrix composites under combined thermo-mechanical fatigue loading. The fatigue life prediction is based on the critical element model. A micromechanics model is used to predict the accumulation of damage in the form of fiber fractures, matrix plasticity and interfacial debonding. The fatigue life is estimated using a linear summation life fraction rule. In the present model, both the local stresses and strength of the constituents of the composite namely fiber, matrix and interface are considered. Results indicate that the predicted fatigue life of unidirectional MMCs agree well with the experimental data for a variety of composites. The model can predict the effects of test temperature, fiber volume fraction, loading frequency and thermomechanical fatigue (TMF) loading well.