MULTIPLE MATRIX CRACKING IN A FIBER-REINFORCED TITANIUM MATRIX COMPOSITE UNDER HIGH-CYCLE FATIGUE

An experimental study of multiple matrix cracking in a fiber-reinforce d titanium alloy has been conducted. The focus has been on the effects of stress amplitude on the saturation crack density and the effects o f crack density on hysteresis behavior. Comparisons have been made wit h predictions based on unit cell models, assuming the sliding resistan ce of the interface to be characterized by a constant interfacial shea r stress. In addition, independent measurements of the sliding stress have been made using fiber pushout tests on both pristine and fatigued specimens.