The research of diagnose for structural damage based on piezoelectric phased array

In this article, finite element simulation about the buried defect is used to simulate the process of detecting buried defects. We built a model similar to the reality. By using two integrated piezoelectric sensors attached to the surface of the structure, elastic waves can be injected into the matrix structure and the sensors can also receive the echo signal. By comparing the received echo signal of the defect structure and of an intact structure, the purpose of recognizing the existence of defects was achieved by extracting the signal reflection caused by the defective components. A comprehensive research based on piezoelectric actuators / sensors phased array for nondestructive testing simulating system was done. Its aim is to build a similar model to the actual situation, and to simulate the actual situations with the same measures to achieve the purpose of identifying the existence of defects. By building a set of active point-to-point scanning system, we detect the damage of aluminum structure by the use of piezoelectric ultrasonic transducer device, which plays the role of actuators and sensors. In addition, an experiment based on the detection of buried defects was carried out. The Ultrasonic flaw detector produces high-frequency and high-voltage pulse signals and it stimulates the actuators to transmit the elastic waves into the block structure. The sensors receive the echo signals, and deal with the echo signals based on continuous wavelet transform, and then study the distribution of time domain and frequency domain. By comparing echo signal, the purpose of identifying the existence of defects is achieved by extracting the echo signal caused by the defective components.