The interaction of Lamb waves with contacting edges of plates are numerically simulated by the elastodynamic finite integration technique. The contacting interface between plates is modeled as a spring-type interface characterized by normal and tangential stiffnesses. For the incidence of the lowest-order symmetric (S0) mode in the low-frequency range below cut-off frequencies, the calculated amplitude reflection/transmission coefficients of the S0 mode are in excellent agreement with the results by the modal decomposition method. For the incidence of the first-order antisymmetric (A1) mode in the frequency range above the cut-off frequency of the A1 mode, the lowest-order antisymmetric (A0) mode is generated by mode conversion at the interface.