Numerical Simulation of Neck Propagation in Double Network Hydrogel

. In this study, we at first employ a nonaffine polymer chains network model to account for the irreversible structural change during the deformation of DN gels. And then, a finite element model of the DN gels under simple tension is constructed. On the other hand, neck propagation is one kind of localized instability and there will be a local transfer of strain energy from one part of the model to neighboring parts. To solve such unstable quasi-static problem, an automatic mechanism provided by Abaqus/Standard is employed. The simulation results show that the nonaffine polymer chains network model together with the stablization algorithm for localized transformation of strain energy can be employed to reproduce the phenomenon of neck propagation in DN gels very well.