Figure 10.
Topological optimisation of a shear‐loaded pad model. (A) Non‐optimised, ventrally fixed model (Young's modulus E = 20 MPa, Poisson's ratio ν = 0.33) with the approximate shape and size of the ventral collagen layer in a digital pad under a shear load FII,L acting on the proximal surface (red). (B) Topological optimisation leads to the formation of longitudinal ridges, to distal flattening, and to curved stress trajectories, similar to the ridges and the distribution as well as orientation of the collagen fibres, respectively, in the ventral collagen layer in the digital pads of Hyla cinerea (see insets). (I) Geometrical models in dorsoproximal view. The non‐optimised model is dimensioned in mm. (II) Von Mises stresses (dorsal view) indicating regions of low mechanical loading. (III) Vector plot of the maximum principal stresses (lateral view) showing the trajectories of force transmission.