Abstract
The contact acoustic nonlinearity based on the nonlinear interaction between elastic waves and contact interface is known to be effective for the detection of micro-cracks. In this study, the contact acoustic nonlinearities of longitudinal and shear waves have been investigated and compared. In experiments, two aluminum blocks were contacted to simulate a solid-solid contact interface, and the contact pressure was adjusted to simulate closed crack conditions. The experimental results showed that the contact acoustic nonlinearity of shear waves is dominant in the generation of the third-order harmonic, whereas the generation of the second-order harmonic is dominant for longitudinal waves. The dominant harmonics had a maximum at a specific contact pressure, and the maximum of the third-order harmonic appeared at a higher contact pressure, than that of the second-order harmonic. This comparison result suggests that the use of the contact acoustic nonlinearity of shear waves may be effective for the detection of more closed cracks because the higher contact pressure simulates more closed cracks.
How to Cite:
Lee, Y. ., Lee, S. ., Choi, S. . & Jhang, K. ., (2019) “Comparison of contact acoustic nonlinearities of longitudinal and shear waves”, Review of Progress in Quantitative Nondestructive Evaluation .
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