Vibration sensing and impact location detection using optical fiber vibration sensor

An intensity-based optical fiber vibration sensor is used to monitor the structural vibration and detect the impact location on a plate. The optical fiber vibration sensor is constructed by placing two cleaved fiber ends, one of which is cantilevered in a hollow glass tube. For vibration sensing, optical fiber vibration sensor is mounted on the carbon fiber composite beam and its response to free vibration and forced vibration is investigated. In impact location detection, four optical fiber vibration sensors whose location is predetermined are used and the different arrival times of impact-generated vibration signal are recorded by FFT analyzer. Impact location can be calculated from these time delays. Experimental results show that optical fiber vibration sensor signals coincide with gap sensor in vibration sensing. The precise locations of impact can be detected on an acrylate plate within 3.4% error limit.