ESTIMATION OF INTERFACIAL SHEAR IN CERAMIC COMPOSITES FROM FRICTIONAL HEATING MEASUREMENTS

A new approach for estimating the interfacial frictional shear stress in fiber-reinforced ceramics is presented. The approach is based upon measurement of the temperature rise which occurs during the cyclic loading of ceramic composites. This temperature rise, which is caused by the frictional slip of fibers within the composite, is related to the level of frictional shear stress which exists along debonded interfaces. To illustrate the technique, the interfacial shear stress in a unidirectional Nicalon-fiber calcium aluminosilicate matrix composite was determined at ambient temperature.