Bond-slip analysis via a thermodynamically consistent interface model combining interlocking, damage and friction

A thermodynamics-based cohesive-zone interface formulation combining adhesion, friction and interlocking is illustrated. Interlocking is modeled exploiting a macroscopic description, which represents the geometry of the interface in the form of a periodic arrangement of distinct microplanes, denoted by Representative Interface Element (RIE). The interaction within each of these surfaces is governed by the combined damage-friction interface formulation proposed by Alfano and Sacco (Int. J. Numer. Meth. Engng 68(5):542-582). Although a simple damage law combined with Coulomb friction and no dilatancy is introduced on each individual microplane, the overall dilatant and hysteretic nature of the bond-slip is predicted as a result of the interaction induced by the presence of the microstructure of the RIE. The formulation is investigated by performing sensitivity analyses and is validated by evaluating its performance in the simulation of pull-out tests under controlled confining pressure. The results of a structural simulation of a pull-out test under variable amplitude repeated loading are also reported. Copyright (C) 2010 John Wiley & Sons, Ltd.