Abstract : Of all mechanical components in aircraft engines, bearings are primordial since they connect rotating parts, namely the rotors, to non-rotating parts, namely the stators. The good running is insured by an internal radial clearance. This latter gives to bearings a strongly nonlinear behavior which can affect rotordynamics. The aim of this thesis is to study the influence of the clearance on rotordynamcis. For this purpose, an experimental set-up, called DDE bench, has been built-up. The first part is devoted to bearing model bearings. The one developed here takes into account the radial clearance and assumes that the balls/raceways contact is of hertzian nature. Specific algorithms based on the multiple shooting method and the time finite element method are used. These methods will be thoroughly studied before presenting some results on relevant examples. The description of the DDE bench will follow. This one will help us to validate the bearing models. It was designed to be as simple as possible, while remaining representative of an actual aircraft engine. Elements of design and updating will be addressed. The obtained results will then be presented.