Effect of microstructural parameters on the fracture behavior of fiber-reinforced ceramics

Abstract

A bridging law which includes both interfacial debonding and sliding properties in fiber-reinforced ceramics is applied to fiber bridging analysis and crack growth problems by treating bridging fibers as a distribution of closure stress. A numerical method to solve distributed spring model of a penny-shaped crack is provided to determine the bridging stress, debond length, crack opening displacement and stress intensity factor. By introducing fracture criteria of the composite and fiber, crack growth behavior in R-curve for the penny-shaped crack are simulated and the effects of such microstructural parameters as interface debonding toughness, compressive residual stress, frictional sliding stress, and fiber volume fraction on the R-curve are quantified in an explicit manner. On the basis of R-curve results, the toughening mechanism of fiber-reinforced ceramics is discussed.