Archive | 2019
Mechanics of viscoelastic buckling in slender hydrogels
Abstract
Hydrogels are soft materials which comprise of trapped solvent within entangled polymeric chains. Although these materials are highly compliant, they are prone to structural and surface instabilities. Buckling, rupture, wrinkling and fracture are some consequences of these instabilities. Under the influence of self-weight and external axial loads, slender hydrogels show viscoelastic buckling. In this paper, the time-dependent response of hydrogels under these conditions has been modelled by considering the energy on account of bending, the work done due to self-weight and external loads, and the viscous damping effects. A Prony series has been used to characterize the compliance and capture the viscoelastic nature of the hydrogels. The parameters of the Prony series were calculated by assuming the hydrogel to be a 3–3 composite. The governing differential equations have been derived using a variational technique. Components of the model have been verified using recorded experimental findings. The model predictions have been reported and a parametric study has been carried out to understand the effect of different system parameters such as the axial load, density and compliance on the viscoelastic response of slender hydrogels.