Fracture Mechanism and Damage Evaluation of FRP/Steel-Concrete Hybrid Girder Using Acoustic Emission Technique

The damage monitoring and evaluation of a fiber-reinforced polymer (FRP)/steel-concrete hybrid box girder subjected to four-point bending is reported in this paper. The target is to integrate the improved mechanical behavior of a FRP/steel-concrete girder with acoustic emission (AE) response. The damage growth and the failure mechanism of the structure are investigated with AE parametric analysis. The amplitude distribution analysis can successfully discriminate the macrodamage signals from the microdamage signals. The time-dependent dynamic analysis of extended features, including RA-AF, b-value, damage parameters, and bending stiffness, show great potential in evaluating damage states, identifying critical points, and providing warnings for catastrophes. The favorable correlation between cumulative AE energy and local strain response provides a viable alternative for meaningful local damage monitoring and prediction. The synthesis analysis of multiple indicators overcomes the disadvantages of single-indicator parameters in to determining complex damage properties, identifying instant damage status, and providing critical warning information for composite structures.