The objective of this study is to develop simultaneous failure detection and strain measurement techniques for health monitoring of composite materials in real-time using optical fiber sensors. To detect the failure signal, EFPI system using laser diode(LD) was used and AEFPI system with ASE broadband source was implemented for the strain measurement. Signals due to matrix cracking and fiber breakage in composite laminates were treated by a signal processing unit in real-time. This paper describes the application of time-frequency analysis such as STFT (Short Time Fourier Transform) and WT(Wavelet Transform) to determine the moment of failure. In order to verify the performance of the optical fiber sensor for stress wave detection, pencil break test with EFPI sensor was performed and the result were compared with that of PZT. The ASE source and LD were applied in a single EFPI sensor using a wavelength division multiplexer to monitor strain and failure simultaneously. From the result of the tensile test, strain measured by the AEFPI agreed with the value of electric strain gage and the failure detection system detected the moment of failure accurately and showed good sensitivity with the infinitesimal failure signal.
