Application of time reversal method to detect the crack of solid plate

Through the success of acoustic development, the concept of the time reversal method is currently being applied in structural health monitoring by the transmission of surface waves. The transmission of surface waves is used to detect the structural cracks in many fields. In this study, the scattered signal of the surface waves due to crack of a structure is utilized to pinpoint the crack location through the time reversal method. In the present investigation, the finite element analysis is applied to simulate the surface wave propagation and to verify the effectiveness of using the time reversal method for locating a crack on a plate. The flexural waves in the plate will produce scattered waves when they propagate through the crack of a plate. The scattered waves may be used to calculate the cracks' location by applying the time reversal theory and the vibration theory together. Experiments have been conducted and prove the feasibility of using the time reversal method to detect crack locations. The signal to noise ratio effect and the array effect in sending and receiving signals are also studied to prove the method's credibility.