Cohesive–frictional interface constitutive model

In the framework of numerical analysis of joined bodies, the present paper is devoted to the constitutivemodeling, via an interface kinematic formulation, of mechanical behaviour of internal adhesive layers.The proposed interface constitutive model couples a cohesive behaviour, based on the damage mechanicstheory, with a frictional one, defined in a non-associative plasticity framework. Namely, the interface formulationfollows the transition of the adhesive material from the sound elastic condition to the fullycracked one. This formulation is able to model, by means of a specific interpretation of the damage variableand in a relevant mathematical setting, the interface intermediate mechanical properties, during themicrocracks spreading process up to the discontinuity surface formation (macrocrack). The constitutivemodeling is performed in fully compliance with the thermodynamic principles, in order to ensure thethermodynamic consistency requirement. In the present work, various monotonic and cyclic loading conditionsare examined in order to show the main features of the constitutive formulation as well as severalsignificant differences with respect to other existing models. Computational efficiency of the interfaceconstitutive model is tested in a numerical application by FEM resolution strategy approach.