Acoustoelastic Effect Analysis of Lamb Wave Based on Finite Element Simulation

Stress characterization is an important basis for quality assessment of key structural components. Therefore, to ensure quality and safety, a non-destructive stress monitoring method is urgently needed. The stress monitoring method based on acoustoelastic of Lamb waves has attracted more and more attention due to the wide interrogation region and high detection efficiency. However, the complex dispersion and multi-modal characteristics of Lamb waves make the influence of stress on Lamb wave not well understood. Here, the numerical simulations based on eigenfrequency analysis are adopted to evaluate the stress monitoring ability of Lamb waves, including the establishment of dispersion curve in prestressed waveguide structure and stress sensitivity analysis of different modes of Lamb waves. The results show that the stress sensitivity of S0 mode is higher than that of A0 mode, and the sensitivity varies significantly at different frequencies. In actual applications, the local optimal excitation frequency should be made according to the structure size and boundary conditions.