Comparative Study of Dispersion Curves for LAMB Waves Using Analytical Solutions and Semi-Analytical Methods

Lamb wave dispersion curves are useful for optimizing the inspection scanning distance that can be covered with good sensitivity in many current applications. However, one of main problems concerning this calculation lies selecting a numerical method is computationally accurate and efficient. In paper, waves generated by Scaled Boundary Finite Element Method, Rayleigh–Lamb equation. For semi-analytical case, waveguide cross-section discretization was performed using isoparametric elements high-order spectral elements. The formulations lead to an eigenvalue problem solved efficiently calculating couples wavenumbers frequencies guarantee mode propagation, basis generating curves. These compared those obtained from analytical solution symmetric antisymmetric modes; both cases, homogeneous plates constant thickness considered. results show agreement when low number elements, or single element shape functions order six computing structure. given computational effort, relative variation respect reference values less than 2%.