Numerical Investigations on Localization of Material Degradation Using Guided Mixing Wave

Nonlinear guided waves mixing technology gains an ascending attention in nondestructive testing field as its capability to resist measuring device nonlinearity. However, recent studies in this topic mainly focus on theoretical analysis. In this article, Lamb waves counter-propagating mixing is explored using a numerical simulation method. Two fundamental Lamb modes(S0 at 1.13 and S0 at 1.82MHz) are selected based on the internal resonance criteria. The mixing wave mode is S1 at 2.95 MHz. A local microdefect is simulated by employing hyperelastic material properties in some regions. Results show that there is a positive correlation of nonlinear acoustic parameter and material degradation level in mixing zone and there is no correlation between nonlinear acoustic parameter and material degradation in fundamental waves propagating routine, which indicate that mixing signal is sensitive to local material defects.