An energy-based work-softening visco-plastic model for zero-thickness interface elements has been developed as an extension of an existing elastic-perfectly-viscoplastic formulation. In the inviscid limit the model also collapses into a well-established fracture mechanics-based elasto-plastic model. The new model is verified satisfactorily for common loading cases at interfaces such as pure tension (mode I) opening, and shear-compression (mixed-mode) sliding, with results that in the long term match the predictions of the fracture mechanics inviscid model.Postprint (published version
