High-temperature acoustic emission detection based on a regenerated phase-shifted FBG sensor

Abstract

Structural health monitoring (SHM) techniques applicable in high-temperature environments are necessary for monitoring the integrity of heat-resistant civil structures. Acoustic emission (AE) detection can be potentially used to establish the real-time passive SHM method. Conventional AE sensors are made from piezoelectric materials, whose operational temperature is limited up to 200 °C. To solve the issue, we proposed a new AE sensing system based on a regenerated fiber Bragg grating (RFBG). The RFBG was fabricated by annealing the conventional FBG, then applied to detect simulated AE waves that were excited by a laser irradiation at temperatures up to 800 °C.