Damage identification in fiber reinforced titanium matrix composites using acoustic emission

Abstract

The fundamentals of acoustic emission behavior in SiC fiber reinforced titanium matrix composites were investigated. In order to obtain preferred damage modes and provide insight into damage identification, the acoustic emission responses in the fiber tensile test, the matrix tensile test, the longitudinal tensile test and the transverse tensile test for the single fiber composite were studied respectively. Extracted signals of fiber fracture, matrix deformation, matrix fracture, fiber fragmentation, fracture of the fiber-matrix reaction layer and interface debonding were analyzed by waveform pattern, frequency contents and time-frequency distribution. The signal characteristics with respect to amplitude, waveform shape, frequency centroid and wave modes were given for different damage modes. Furthermore, the generation and propagation mechanisms of multiple signals were also discussed with the assistance of theoretical models.