平板の折曲部におけるラム波の反射・透過特性

抄録

The Lamb wave propagation in a linear elastic isotropic bent plate is studied theoretically and numerically. The modal amplitudes of reflected and transmitted Lamb waves when a monochromatic Lamb wave impinges on a smooth corner zone are calculated using the modal decomposition method. As a result, it is shown that the single mode incidence of either the lowest-order symmetric (S0) or the lowest-order antisymmetric (A0) mode in the frequency range below the cutoff frequencies of the higher-order modes generates both S0 and A0 modes in the reflected and transmitted fields. Furthermore, these reflected and transmitted waves are found to satisfy the reciprocal relation. Namely, the energy ratio of the scattered A0 to the incident S0 modes coincides with that of the scattered S0 to the incident A0 modes. These findings of the theoretical analysis are validated by comparing with the results of a two-dimensional plane-strain dynamic finite element simulation.