Optical fiber sensing of small cracks in isotropic homogeneous materials

Monitoring of cracks and other damages is an integral part of ongoing research. Cracks and other damages may destroy the integrity of structures and even cause engineering accidents. Hence, it is of utmost importance to monitor the development of cracks in structures well in time to restrict the extent of overall damage. In this paper, a novel fiber optic sensor is discussed; this sensor is developed to monitor small cracks (crack openings between 0 and 0.8 mm). The sensing principle of the sensor is first introduced and then the influence of dimensional parameters on the sensor is discussed through experimental investigations. The test results indicate that the sensor has a good initial perception capacity and a high sensitivity. Furthermore, the sensor is very effective in monitoring of small cracks.