Research on the Nondestructive Detection of Ultrasonic Guided Wave Based on the Time Reversal Method

Abstract

Because there are many mode transformations when the ultrasonic guided waves run into defects in the pipeline, the reflected signals got by means of the traditional ultrasonic guided wave technique are complex and the amplitudes are small. The time reversal method is a way to intercept the reflected signals in the initial results with a certain bandwidth and excite the time reversal guided waves on the corresponding nodes. In this way, energies of the guided wave are focused in time and space. By comparing the accuracy of defects identification in the straight pipes and the bent pipes with the traditional ultrasonic guided wave method and the time reversal method, this paper proves that the time reversal method has many advantages over the tradition ultrasonic guided wave method. The time reversal method overcomes disadvantages of the traditional guided wave technique and improves the identification degree and accuracy of defects effectively. It lays the foundation for the final defect identification.