Experimental and numerical studies of the oblique defects in the pipes using a chaotic oscillator based on ultrasonic guided waves

The longitudinal ultrasonic guided waves in oblique defects pipes were investigated experimentally and numerically in the paper. A novel method of the defect detection for pipes is proposed based on the Duffing-Holmes chaotic oscillator. Five kinds of defects with inclined angle of 0°, 30°, 45°, 60° and 90° were discussed and analyzed, respectively. Based on the experiment, the corresponding simulations were conducted by using finite element software LS-DYNA. Both experimental and numerical results show that this proposed method could be used to inspect the weaker guided waves; and the reflection coefficient of echo increases with the decrease of the inclined angle.