Spatial location of fibre failure during fatigue of Ti matrix composites reinforced by SiC fibres

The spatial location of fibre failure in titanium matrix composite specimens reinforced by continuous silicon carbide fibres during fatigue has been determined. The position of fibre failure along the fibre length direction was detected by two acoustic emission (AE) sensors using a linear location technique. The importance of sensor positions and AE threshold values on the resolution is analysed by examining the waveform of the AE signals. In addition, a particular calibration and calculation method has been developed to take into account the different acoustic wave velocities in the composite specimen and grips. The position of the broken fibre was detected by a fibre probing (FP) technique, which includes the measurement of electrical resistance of the core of the fibres.