Transmission and reflection of A0 mode Lamb wave in a plate overlap

Lamb wave propagation in a plate overlap is investigated. Transmission and reflection coefficients for incident Lamb waves of A0 mode across the overlap region are numerically calculated using a hybrid BE-FE method. Transmission and reflection coefficients of the Lamb wave across the overlap region are studied as a function of frequency and overlap length. In addition, mode conversion phenomena from the incident waves within the overlap region are also included in the numerical study. A few experiments were also conducted for measurements of transmission and reflection coefficients for incident A0 mode wave in overlap-shaped steel plates with two different overlap areas. The experimental results are in good agreement with the numerical calculations. The numerical and experimental results can be used to establish guidelines for NDE in overlapped plates and in multilayer structures with various joints by selecting modes and tuning frequency.