Modal flexibility-based damage detection technique of steel beam by dynamic strain measurements using FBG sensors

The development of smart sensors for structural health monitoring and damage detection has been advanced remarkably in recent years. Nowadays fiber optic sensors, especially fiber Bragg grating (FBG) sensors, have attracted many researchers' interest for their attractive features, such as multiplexing capability, durability, lightweight, electromagnetic interference immunity. In this paper, modal flexibility-based damage detection approach of steel beam by dynamic strain measurements using FBG sensors are presented. An experimental Study was conducted to investigate the feasibility of the method for damage detection and localization. It has been found that the strain-flexibility approach using dynamic strain measurements from FBG sensors can successfully detect and localize multiple small damages near the sensors. However, the damage detection range of the present short-gage FBG sensors seems rather narrow. Long-gage FBG sensors would be a possible solution.