Modeling the effect of damage on electrical resistivity of melt-infiltrated SiC/SiC composites

Electrical resistivity (ER) measurements are a possible health monitoring technique for ceramic matrix composite components in future aerospace applications. In order to use ER measurements to detect and identify damage, it is necessary to understand how each specific damage state will affect the ER response. In this study, finite element models are developed and applied to quantify the effect of specific damage states on the ER response in a melt-infiltrated silicon carbide (SiC) fiber-reinforced SiC composite. The ER of several damage states are calculated by simulating the electric current flow through the damaged microstructure. This is achieved by performing the numerical solution of the steady-state conservation of charge density equation. Numerical results reveal the effect of various cracking features on the ER response such as type of cracking, extent of cracking, crack density and fiber/matrix debonding.