We have developed fiber optic strain and vibration sensors (FOSVS) suited for health monitoring of structures. A fiber optic gap sensor made of multi-mode fibers, broad-band light, two photo detectors and an FBG filter were used to compose the sensor system. The gap sensor was composed of a cantilever fiber and a reflector fiber. The axial strain of the sensor was measured from the reflected interfered signal. The amplitude of the transmitted signal through the reflector fiber was used to measure the transverse vibration of the cantilever fiber. In the present study, the sensors were embedded in epoxy plates and cantilever vibration tests were conducted. From the experimental and theoretical results, it appeared that the embedded FOSVS in specimens could measure dynamic strain and vibration of a vibrating cantilever plate simultaneously. From these results, it can be concluded that the FOSVS sensor has practical capability of simultaneous measurement of internal strain and vibration of materials.
