Abstract:

When the spider orb web stops a prey, the web dissipates impact energy by three routes: internal dissipation within the radial silk, internal dissipation within the spiral silk and aerodynamic dissipation. This paper investigates the energy dissipation mechanism of spider orb webs from the mechanics point of view. Firstly, the dynamic response and energy dissipation of a single spider silk under transverse impact are studied analytically and numerically. The congruence of dynamic response curve validates the accuracy of finite element analysis. Then the whole web is modeled using the finite element method and the re-spective contribution of each route to total energy dissipation during the simulated prey impact is obtained, which agrees with published experimental results. Finally, the influence of initial impact kinetic energy on the fraction distribution of three routes is demonstrated based on the finite element model. The mechanical mechanism of energy dissipation of spider orb webs is discussed and the reason for the differences among the existing opinions is speculated.

Key words: silk, spider webs, energy dissipation, finite element