Diagnostics Figure 4

Figure 4. Photomicrographs and photographs showing features that can provide a nonlinear response to the bulk material when excited in a wave field. Dislocations in Type 2 diamond and sapphire, a single crack in ceramic (barium magnesium silicate doped with borosilicate glass), a sandstone showing the soft bond system, a crack in a connecting rod, bearing cap, and concrete all lead to very similar nonlinear wave behaviors.