STRAIN FIELDS AND DAMAGE AROUND NOTCHES IN CERAMIC-MATRIX COMPOSITES

Strain development in several notched ceramic-matrix composites (CMCs) has been monitored over a broad range of load. This was achieved by u sing phase-shifting moire interferometry, which provides a map of the surface strains. A sequence of fringe patterns was used to chart the e volution of strain redistribution as a function of load. The ensuing s trains were related to the micromechanical damage mechanisms. Stress c oncentrations were estimated from the strains by using stress/strain c urves. Implications for the notch sensitivity of CMCs are discussed.