Er. Delosrios et al., MODELING THE CONDITIONS FOR FATIGUE FAILURE IN METAL-MATRIX COMPOSITES, Fatigue & fracture of engineering materials & structures, 19(9), 1996, pp. 1093-1105
An investigation on the fatigue crack growth (FCG) and fatigue failure
in metal matrix composites (MMCs) has been conducted using a model ba
sed on micromechanical elasto-plastic fracture mechanics (EPFM) princi
ples. To evaluate the model comparisons between experimental and predi
cted fatigue life have been made for two silicon carbide strengthened
(SCS)-6/Ti-based MMCs. Conditions for crack arrest and crack instabili
ty have also been considered in order to define the fatigue damage lim
its. Crack arrest occurs from the added effects of fibre bridging and
the constraint provided by the fibre on matrix microplasticity, while
crack instability is achieved when the fibre constraint effect is mini
mum and the fatigue resistance of the material is reduced due to the a
ccumulation of fatigue damage. Comparisons of the predicted fatigue da
mage limits with experimental results show good agreement which underl
ines the usefulness of a microstructural fracture mechanics model.