Wave propagation in a continuum phononic material with geomaterial-inspired nonlinearity

Abstract

This presentation discusses the nonlinear wave propagation in a continuum phononic material with nonlinear mechanisms inspired by geomaterials. Geomaterials can exhibit nonlinear wave responses due to mechanisms such as material nonlinearity or lack of bonding between phases of material. We study the interaction of nonlinear and phononic behavior by introducing two geomaterial-inspired nonlinear mechanisms into a phononic material. The influence of material nonlinearity and nonlinearity due to delaminations between material phases are studied in a bilayer finite element model composed of alternating layers of stiff linear elastic material and soft hyperelastic material. To model delaminations, a binary contact condition is applied at the interface between layers. Measurements of the quasi-static nonlinear mechanical response of delaminations of different lengths are used as inputs into the finite element method simulations. The influence of the delamination nonlinearity plus material nonlinearity on the phononic material is studied in a full-scale time-domainfinite element model. This model is used to further probe the interaction between phononic band gaps and nonlinear wave response, as well as the dependence of delamination size and location on the nonlinear wave response.