A ID SAFE/SAFE mode-matching approach for Lamb wave scattering study in bent plates

A one-dimensional(1D) mode-matching approach to handle Lamb wave scattering in bent plate is proposed in this article. The eigenvalue problem associated with guided waves along circumferential direction of the curved plate is constructed in Comsol using semi-analytical finite element(SAFE) method, and together with that in flat plate are solved in frequency-domain. In both cases the mode solutions corresponding to all real and a number of complex wavenumbers with the least imaginary parts, are used to one-dimensional field-matching at the junctions of them to get the scattering matrix of Lamb modes. In comparison with the time or frequency domain two-dimensional numerical models, theoretically with less calculation cost and modeling complexity, the method manifests almost equal effectiveness and mutual verification from experiments. It’s found among all the coefficients, the mode transmitting in themselves usually dominate the scattering energy, except the cases when the bent have a rigid inner corner, a 180° bent angle, or the incident waves are at the cut-on frequency of propagating mode.