| Literature DB >> 24792684 |
Vamshi Krishna Chillara1, Cliff J Lissenden2.
Abstract
Harmonic generation from non-cumulative fundamental symmetric (S0) and antisymmetric (A0) 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.Keywords: Higher harmonic generation; Nonlinear guided waves; Nonlinear ultrasound; Ultrasonics
Year: 2014 PMID: 24792684 DOI: 10.1016/j.ultras.2014.04.009
Source DB: PubMed Journal: Ultrasonics ISSN: 0041-624X Impact factor: 2.890