Theoretical Evaluation of Strength Degradation During Monotonic and Cyclic Loading in Unidirectional Metal Matrix Composites

By implementing the concept of critical fibre length into a modified version of the Law of Mixtures and considering the effect of the thermal residual stresses, the monotonic strength of unidirectional MMCs is predicted. The above is also used as a reference value for strength degradation in the case of cyclic loading. Herein, the conditions of constraint effect and flow resistance degradation are taken as the major, strength controlling, damage mechanisms. The approach is then executed for two kinds of titanium matrices and the commonly used SCS-6 fibre. The approach allows the study of the above composite system in terms of the mechanical properties of the constituent phases and the fibre volume fraction.