Damage analysis of FRP/steel composite plates using acoustic emission

Fibre-reinforced plastic (FRP)/steel composite is gaining momentum in civil engineering for repair, permanent formwork and external reinforcement. It is of vital importance to research the damage propagation of the new composite under loading. In this paper, we prepared four identical specimens of FRP/steel composite plates to conduct our test. Two of the specimens were under uniaxial loading, and the other two were under cyclic uniaxial loading. During the test, we monitored the specimens by acoustic emission (AE). AE is a suitable method to monitor the damage process of composite material because of its nondestructive and real-time features. In this study, we used a sentry function to assess the damage process of the specimens that were under uniaxial loading and calculated the index of damage (ID) and the modified index of damage (MID) to analyse the damage of the specimens that were under cyclic uniaxial loading.