The purpose of this thesis is to study the influence of plasticity on the delamination and buckling of thin films deposited on substrates. By combining atomistic simulations and analytic calculations performed in the framework of continuum mechanics, the microscopic processes consisting in the sliding of atoms located at the base of the blister has been characterized during the formation of a straight-sided blister. This sliding effect has been found to increase the maximum deflection of the buckling structure. It also modifies the delamination process of the interface. Taking into account this sliding into the Föppl-von Kármán theory of thin plates (FvK), the shape of the straight-sided blister and the delamination process have been characterized. The consistency between the atomistic simulations and the model explains how the buckling-driven delamination proceeds without introducing any dependence between the adhesion energy and the mode of mixity. The initiation of the buckling from a dislocation-induced interface step has also been investigated. The simulations show that, before buckling, the film delaminates on both sides of the step and a sliding mechanism is also observed. A critical buckling strain which accounts for these phenomena has been analytically determined in the FvK framework. The simulation results and the elastic model explain, as it has also been experimentally observed, why blistering preferentially occurs above step-like defects.
