Mechanical characterization of stress softening in double network hydrogels

Abstract

In this paper, a micro-mechanical model is introduce to characterize the stress softening phenomenon in double network hydrogels. Damage in polymer matrices under deformation, which appears as the rupture of cross-linking, is assumed to result in stress softening. The evolution of a polymer matrix is described with the network evolution method by Dargazany and Itskov [Dargazany and Itskov, International Journal of Solids and Structures, 2009, 46, 2967]. The model includes a number of physically-motivated material parameters and obtains good agreement against different sets of experimental data of uniaxial cyclic tension tests.