Computer simulation of crack propagation in whisker-reinforced ceramic composites

A comprehensive computer program has been developed to simulate the process of crack propagation in whisker-reinforced ceramic composites. Two toughening mechanisms, crack bridging and crack deflection, are considered in the simulation. The fracture process of the composites is simulated in order to understand the complex mechanisms which occur between a propagating crack and whiskers. The results provided by the simulation indicate that there is a interaction between the two toughening mechanisms when they operate simultaneously. The values of the combined toughening are greater than that of each one individual toughening and less than their sum. With the increase of the whisker contents, the toughening effects of crack bridging and crack deflection increase, and the dominant toughening mechanism changes gradually from crack deflection to crack bridging. The best toughening effect can be obtained when whiskers are at high angles with the crack plane. The results of the simulation are in good agreement with that of the experiments for some ceramic composites.