Stiffness Degradation in Metal Matrix Composites Caused by Thermomechanical Fatigue Loading

Damage during thermomechanical fatigue loading of a metal matrix composite is represented by a vector. The undamaged material is characterized by the generalized Hooke’s law for transversely isotropic materials. The residual elastic properties of metal matrix composite are related to the initial elastic properties by the damage vector. The residual stiffness properties are then correlated with the number of fatigue cycles to failure. The ability to use this concept to determine the safe strength requirement for a given cyclic life is discussed.