Non associative damage interface model for mixed mode delamination and frictional contact

The present paper proposes a new interface constitutive model based on the non-associative damage mechanics and frictional plasticity. The model is developed in a thermodynamically consistent framework, with three independent damage variables. The non associative flow rules drive the concurrent evolution of the three damage variables. The interface model provides two independent values for the mode I fracture energy and the mode II fracture energy and it is able to accurately reproduce arbitrary mixed mode fracture conditions. The model can also take into account the presence of frictional effects both at the fully debonded zones and at the partially debonded ones. The experimental tests developed by Benzeggagh and Kenane with seven different mixed mode ratios have been numerically simulated with a unique set of constitutive parameters. The split shear torsion, for the evaluation of the mode III delamination toughness, has been analysed by a three-dimensional numerical simulation.