Viscoelastic solids explain spider web stickiness

Crack propagation in viscoelastic solids.

We study crack propagation in a viscoelastic solid. Using simple arguments, we derive equations for the velocity dependence of the crack-tip radius, a (v) , and for the energy per unit area to propagate the crack, G (v) . For a viscoelastic modulus E (omega) which increases as omega(1-s) (0< s< 1) in the transition region between the rubbery region and the glassy region, we find that a (v) appr...

Lubrication of soft viscoelastic solids

Lubrication flows appear in many applications in engineering, biophysics, and in nature. Separation of surfaces and minimisation of friction and wear is achieved when the lubrication fluid builds up a lift force. In this paper we analyse soft lubricated contacts by treating the solid walls as viscoelastic: soft materials are typically not purely elastic, but dissipate energy under dynamical loa...

Web stickiness optimised to humidity

Blundering into a sticky spider’s web is unpleasant enough, evenwhenyouare large and can tear free. But for smaller creatures, impacting a web is a death sentence. Brent Opell and colleagues from Virginia Tech, USA, explain that the stickiness of a web depends on the stretchiness of the adhesive globules that are dotted along the spiral thread. ‘When an insect flies into an orb web, its legs, w...

Indentation Analysis of Fractional Viscoelastic Solids

Critical viscoelastic response in jammed solids

We determine the linear viscoelastic response of jammed packings of athermal repulsive viscous spheres, a model for emulsions, wet foams, and soft colloidal suspensions. We numerically measure the complex shear modulus, a fundamental characterization of the response, and demonstrate that low frequency response displays dynamic critical scaling near unjamming. Viscoelastic shear response is gove...