Fiber Bragg Gratings Array for Structural Health Monitoring

Experimental and numerical analyses have been carried out to demonstrate the feasibility and evaluate the limitation of using fiber Bragg gratings for impact source location on a cold-rolled aluminum plate. Within the area enveloped by a four-FBG-array, source location is reasonably accurate. Beyond that area, prediction error may not be acceptable. Numerical simulations show that such error may be attributed to the limitation of equipment resolution on the one hand, and angular insensitivity of the FBG on the other hand. Based on the results, it is reasoned that prediction accuracy can be improved by employing stronger light source, steeper filter response, and orthogonal rosettes instead of single axis FBGs.