Mechanical characterization of stress softening in double network hydrogels

TL;DR

This paper introduces a micro-mechanical model to understand stress softening in double network hydrogels, linking damage to polymer rupture and matching experimental cyclic tension data.

Contribution

A novel micro-mechanical model for stress softening in double network hydrogels based on damage and network evolution.

Findings

Model accurately predicts stress softening behavior.

Good agreement with experimental cyclic tension data.

Provides insights into damage mechanisms in 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.