A finite viscoelastic phase-field model for prediction of crack propagation speed in elastomers

Crack propagation in soft viscoelastic solids is crucial in many applications, yet accurate modeling of their fracture behavior, particularly the rate-dependent fracture toughness, remains a challenge. We address this by proposing a thermodynamically consistent phase-field fracture model for viscoelastic materials. The model incorporates both equilibrium and non-equilibrium elastic energies, along with distinct dissipation mechanisms for viscous losses and irreversible damage processes. Importantly, two characteristic time scales are introduced, reflecting the distinct nature of viscous relaxation and damage evolution, both of which significantly influence crack propagation dynamics. Numerical simulations are performed to investigate the impact of the different energy contributions on the fracture propagation in elastomeric membranes, accompanied by comparisons to experimental results.