Published: 30 September 2011

Nonlinear ultrasonic test using PZT transducer for crack detection in metallic component

Yongming Feng1
Li Zhou2
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Abstract

A crack detection technique based on nonlinear ultrasonic is developed in this study. Acoustic waves at a chosen frequency are generated using an actuating lead zirconate titanate (PZT) transducer, and they travel through the target structure before being received by a sensing PZT wafer. Unlike an undamaged medium, a cracked medium exhibits high acoustic nonlinearity, which is manifested as harmonics in the power spectrum of the received signal. Experimental results also indicate that the harmonic components increase nonlinearly in magnitude with increasing amplitude of the input signal. The proposed technique identifies the presence of cracks by looking at the two aforementioned features: harmonics and their nonlinear relationship to the input amplitude. The effectiveness of the technique has been tested on aluminum specimens.

About this article

Received
08 July 2011
Accepted
05 September 2011
Published
30 September 2011
Keywords
nonlinear ultrasonic
fatigue crack
metallic component
crack detection