Nonlinear guided waves in plates: A numerical perspective

• Harmonic generation from fundamental modes in plate is numerically investigated.
• Role of material and geometric nonlinearities in harmonic generation is assessed.
• It was found that group velocity matching is not necessary for harmonic generation.
• Phenomenon of mode-interaction is demonstrated.

Harmonic generation from non-cumulative fundamental symmetric (S0S0) and antisymmetric (A0A0) modes in plate is studied from a numerical standpoint. The contribution to harmonic generation from material nonlinearity is shown to be larger than that from geometric nonlinearity. Also, increasing the magnitude of the higher order elastic constants increases the amplitude of second harmonics. Second harmonic generation from non-phase-matched modes illustrates that group velocity matching is not a necessary condition for harmonic generation. Additionally, harmonic generation from primary mode is continuous and once generated, higher harmonics propagate independently. Lastly, the phenomenon of mode-interaction to generate sum and difference frequencies is demonstrated.