FEM Simulation Study for Damage Acoustic Emission Signals on Composite Laminated Plate

Composite materials are widely used in high-speed rail transportation, but the multiple damage may include matrix cracking, matrix/fiber debonding, delamination and fiber breakage which can be caused by impacts, fatigue, or overloading in the manufacture, assembly and service process. The type and location of the damage can be identified by structural health monitoring (SHM), thus the occurrence of fatal accidents can be avoided. When any damage occurs in the composite material, different transient non-stationary acoustic emission (AE) signals can be detected. However, the high cost and unrepeatability are the restraining factors of practicality experiment. Therefore, the simulation study has become an effective method to solve this problem. This paper proposes a method to establish a composite laminated plate model with interface by setting cohesive elements. Compared with traditional ways, it greatly improves the facticity of the simulation model. Based on this model, four kinds of AE signals represented four different damages are simulated using the sine modulation signals as the excitation, and the effectiveness of this method is confirmed after doing the frequency spectrum analysis. In addition, the excitation signal is applied on the different depth of the plates, and the sensing signal features are analyzed.