A cohesive interface model based on damage and friction

A new cohesive-zone model is presented based on the combination of an elastic-damage formulation, which simulates the interface decohesion, and a friction contact model. The classical mesomechanic assumption is made whereby a representative area of the interface can be additively decomposed into an undamaged part and a damaged part, so that the ratio between the damaged part and the total area represents a damage parameter ranging from 0 to 1. The main idea consists of adding a Coulomb-like friction term for the stress only on the damaged part of the interface, while the decohesion model takes into account mixed-mode fracture and specializes to piecewise linear interface laws for pure-mode problems. Numerical results are presented for the simulation of a benchmark test for the analysis of concrete dams, in which the proposed model is used to simulate the behaviour of the soil-concrete interface at the base of the dam.