Large-scale simulation of Lamb wave propagation by hybrid boundary element method

Abstract

The simulation of Lamb wave propagation is an efficient tool to improve the accuracy of nondestructive inspection of metallic plates by ultrasonic methods. However the widely used modeling techniques such as FDM, FEM and BEM require too much computation time. Since the Lamb wave technique is often used for large structures relative to the ultrasonic wavelength (e.g. fluid pipes, storage tanks etc.), its computing requires a huge number of nodes or elements which are nearly proportional to computation time. This study is therefore focused on the Hybrid BEM (HBEM), which is the combination of exact Lamb wave theory and BEM for two-dimensional elastodynamics. In HBEM much less nodes should be considered in the calculations, and it results in much shorter calculation time. A description of HBEM used for Lamb wave simulation is given in this paper. The parameters for the exact solution of Lamb wave propagation were optimized to achieve the shortest calculation time. Finally, an effective simulation of a large structure is presented under pre-determined conditions.