Assessment of the Interfacial Properties of Ceramic-Matrix Composites Using Strain Partition under Load

The interfacial sliding stress is a key parameter in the global behavior of ceramic-matrix composites. An ultrasonic characterization, through the complete determination of the stiffness tensor along a tensile test, detects all the damage mechanisms: transverse matrix microcracking and the existence of longitudinal cracks at the fiber/matrix interface. It also allows a strain partition under load. A micromechanical model is established and gives access to the value of the interfacial sliding stress during the entire tensile test, whether the damage occurs at the mesostructural or at the microstructural level of the composite.