Thermal conductance of delamination cracks in a fiber-reinforced ceramic composite

The thermal conductance of delamination cracks in a unidirectionally reinfo rced ceramic composite is investigated. A phase-sensitive photothermal tech nique is used to measure the crack conductance in situ under load. Special emphasis is given to the effects of the local crack opening displacement (d elta). A crack conductance model that considers the contributions from both the air and the fibers within the crack is developed and compared with the measurements. Despite considerable scatter in the experimental data, the m odel adequately predicts the increased conductance that is associated with fiber bridging, as well as the overall trend that is observed with delta.