Detection of Arbitrary Frequency Ultrasonic Guided Wave Signals Based on the Time-Shift Duffing Oscillator

Low detection accuracy and narrow detection range are observed when detecting weak guided wave signals with the Duffing oscillator as a result of a limited frequency band. In order to solve these problems, we proposed a detection method for detecting weak ultrasonic guided waves of arbitrary frequency based on a defect detection method using the Duffing oscillator scanned by a moving window and combined with variable scale and resampling. In this paper, the proposed method by examining the defect echo signals collected on steel pipe samples and detecting ultrasonic guided wave signals excited by arbitrary frequency was effectively validated. Experiment results show that the proposed approach can be used to detect guided wave signals of arbitrary frequency and arbitrary sampling step size with the fixed system. It is very important for expanding the range of defect detection in pipes with guided ultrasonic waves and improving the sensitivity for detecting small defects in engineering applications.