Structure multi-damage monitoring based on the piezoelectric ultrasonic phased array

The active structural health monitoring based on ultrasonic phased array is a new development direction in the field of aircraft structural health monitoring, which is also one of the difficult points of current research, and ultrasonic phased array structural health monitoring is still in its infancy in China. Based on the existing application of ultrasonic phased array technology of single damage location, multi-damage monitoring is further studied in the aircraft structure. Direction of arrive can be controlled by time delay and the multi-damage location can be identified by scanning structure in all orient. Experiments compared the damage reflection signals of different angles before the delayed with the signals after the delayed and the synthesized signal on the aluminum structure, and the results verified the ultrasonic phased array can effectively improve the multi-damage signal energy by delaying and superposing them, as well as, reduce the energy of the signal where there is no damage, thus increasing the signal to noise ratio, and has a high accuracy for multiple damage identification.