ABSTRACT
In this paper we introduce a consistent constitutive model capturing the behavior of a 3D interface under both monotonic and cyclic loading. The model accounts for the interaction of dissipative effects during a combined decohesion-compression and sliding loading introduced through a smooth cap threshold function and non-associative flow potential. The proposed flow potential provides the possibility to couple the damage evolution of decohesion and sliding and to control the degree of this coupling. High computational efficiency is achieved by requiring a constant gradient of the threshold function in the normal direction with respect to the yield locus. As a result, a single-step return-mapping procedure without the need for iteration increases the computational efficiency. To capture the fatigue behavior in heterogeneous structures, the model consistently reflects the dissipative mechanisms of fatigue damage evolution at subcritical load levels using a cumulative measure of deformation as a damage-driving variable. Further effects of the interface response, such as shear dilatancy and vertex effect, are captured by the proposed model as demonstrated using elementary studies. A systematic calibration and validation procedure is included for selected applications showing a pull-out response of concrete-steel interface under monotonic and cyclic loading captured with a consistent set of material parameters.
