S0 Lamb wave scattering in plate structures using physics-enhanced TransUNet

Lamb wave scattering offers valuable insights into material properties, defect characteristics, and wave propagation behaviors, making it a prominent research topic in the fields of non-destructive testing and structural health monitoring. Analytical methods, while offering theoretical analysis, are often limited to simple defect geometries and homogeneous media. Numerical methods such as the boundary element method and hybrid techniques can handle complex structures but suffer from computational costs, particularly at high frequencies due to the need for fine discretization. To overcome these challenges, this study proposes a physics-enhanced TransUNet (PTUNet) for solving the scattered wavefield of S0 Lamb waves in plate structures with irregular defects. PTUNet combines the local feature extraction capability with the global modeling capacity while employing finite difference approach to incorporate the Kirchhoff-Love plate theory as a physical constraint. The effectiveness of the proposed method is validated through numerical simulations on random defects and experimental measurements using a scanning laser Doppler vibrometer on a 1.5 mm-thick aluminum plate. The results demonstrate that PTUNet accurately predicts wave propagation, mode conversion, and intricate scattering characteristics, achieving reasonable agreement with both finite element simulations and experimental observations. PTUNet presents a promising approach for wavefield modeling and defect characterization, with potential applications in acoustic scattering problems.