Figure 10.

Elastic triangular lattice with soft internal links, whose domain is divided into two regions where the spinners rotate in opposite directions. A time-harmonic displacement is imposed on a node at the interface between the two regions. Interfacial waveforms are generated, whose direction depends on the frequency of the imposed displacement: (a) ω = 2.7, (b) ω = 2.9 (see also inset in figure 8e). In the computations, the absolute value of the spinner constant is |α| = 0.8 and the internal links inside the hexagonal cell are very soft (ε = 0.01). (Online version in colour.)