Vibration measurement of smart composite structures by using the new intensity modulated optical fiber sensor

A new intensity modulated optical fiber vibration sensor has been employed to monitor the vibration signal in the smart composite structures in this paper. The advantages of this sensor are the lower cost and the easy-to-use system. The sensors were fabricated using conventional 50/125 step-index multimode optical fibers and the custom-drawn epoxy resin capillary tube. The construction of this sensor is like the extrinsic Fabry-Perot interferometric(EFPI). A face coupling theory of the intensity modulated fiber optic vibration sensor is developed. This optical fiber sensor has been embedded in the end of the smart composite cantilevered beam. The static and dynamic characteristics of this optical fiber vibration sensor have been tested. At same time, the compared test of this sensor with the commercial piezoelectric transducer are also finished. The experimental results show that the new type intensity modulated optical fiber vibration sensor has higher sensitivity and better dynamic and static properties. The spectrum response of this sensor are also agreeable to that of the commercial transducer.