Conclusions

Nonlinear wave propagation can be described with a purely geometric parameterization or with a nonlinear material characterization (or both). The finite strain approach lends itself as a natural extension to the usual linearly elastic wave propagation description. A more complicated and maybe more realistic treatment incorporates a nonlinear stress-strain relationship. However additional parameters have to be estimated. The one-dimensional Duffing equation is described and an extension to three component 3-D data is proposed, mimicing its 1-D counterpart.