A statistical model of fatigue damage evolution in particulate-reinforced metal-matrix-composites

A statistical model of fatigue damage evolution has been developed for part iculate-reinforced metal-matrix-composites (MMCs) by taking into considerat ions both the initial damage distribution and the effect of particulate rei nforcement on fatigue damage development. The growth of microscopically fat igue-damaged regions in particulate-reinforced MMCs is considered as a stoc hastic process, and both the non-equilibrium statistical method and minimum strength principle are used to establish the evolution equation of fatigue damage. The fatigue damage evolution equation developed in the present stu dy characterizes not only the kinetic process of fatigue damage evolution b ut also sets up the relationship between the mechanism of fatigue damage gr owth of the microscopically damaged regions and the result of fatigue damag e, i.e. degradation of mechanical properties of particulate-reinforced MMCs . A new expression for calculating the cumulative fatigue damage and a new formula for predicting the average fatigue strength of the particulate-rein forced MMCs are derived. Experimental data of 2080Al/SiCp composites are an alysed and compared with results obtained with the present model. It is sho wn that the experimental results can be described well by the calculations.