Electrical Resistance And Acoustic Emission During Fatigue Testing Of Pristine And High Velocity Impact Sic/Sic Composites At Room And Elevated Temperature

Electrical resistance (ER) is a relatively new approach for real-time monitoring and evaluating damage in SiC/SiC composites for a variety of loading conditions. In this study, ER of woven silicon carbide fiber-reinforced silicon carbide composite systems in their pristine and impacted state were measured under cyclic loading conditions at room and high temperature (1200C). In addition, modal acoustic emission (AE) was also monitored, which can reveal the occasion of matrix cracks and fiber. ER measurement and AE technique are shown in this study to be useful methods to monitor damage and indicate the failure under cyclic loading. Based on the slope of the ER evolution, an initial attempt has been made to develop a method allowing a critical damage phase to be identified. While the physical meaning of the critical point is not yet clear, it has the potential to allow the failure to be indicated at its early stage.