Fig. 7.

Tension propagation model. (Top) Bending equilibrium at cell i. (Bottom) Tension propagation from cell i to cell i+1. Tension ${\mathrm{\tau }}_{\mathrm{i},\mathrm{j}}^{\mathrm{k}}$ is transformed with friction force ${\mathrm{f}}_{\mathrm{i}+1,\mathrm{j}}^{\mathrm{k}}$ to tension ${\mathrm{\tau }}_{\mathrm{i}+1,\mathrm{j}}^{\mathrm{k}}$