Cumulative second-harmonic generation of Lamb-mode propagation in a solid plate

This article describes the physical process of cumulative second-harmonic generation of Lamb-mode propagation in a solid plate. In general, cumulative second-harmonic generation of a dispersive guided wave propagation does not occur. However, the present results show that the second harmonic of Lamb-mode propagation arising from the nonlinear interaction of partial bulk waves and the restriction of the two boundaries of the solid plate does have a cumulative effect once some conditions are satisfied. Through boundary and initial conditions of excitation, the analytical expression of the cumulative second harmonic of Lamb-mode propagation has been determined. Numerical results reveal that the cumulative second-harmonic fields are symmetrical regardless of whether Lamb-mode propagation is symmetrical or antisymmetrical, and that the cumulative second-harmonic field patterns of Lamb-mode propagation are associated with the position of excitation source. (C) 1999 American Institute of Physics. [S0021-8979(99)00506-X].