Fatigue and frictional heating in ceramic matrix composites

This paper describes an experimental technique for monitoring the damage evolution in ceramic matrix composites during cyclic testing. The damage is related to heat dissipation, which may be measured as radiated heat from the surface of the test specimen. In the present experimental set-up an isothermal chamber has been utilized.

The chamber walls and the grips are water-cooled to allow a consistent calculation of the conductive heat loss to the grips, the radiative heat loss to the chamber walls, and the convective heat loss to the air. An infrared camera scans the surface continously with a high spatial and temperature resolution and changes in the heat dissipation can be measured almost instantaneously.

The technique has been tested on uni-directional ceramic matrix composites. Experimental results are shown and the possibilities and the limitations of the technique are discussed.