Experimental model validation of a non-linear structure with lap-joint using the physical space approach

It is commonly accepted that bolted structures can present nonlinearities which can be caused by the contact conditions and that these are severely exercised for large vibration amplitudes. Several researches have targeted these joint's nonlinear behaviours and experimental model validations have demonstrated to be successful. The scope of this paper is to demonstrate that nonlinearities which are quantified in the modal space can be correlated with the same ones which are identified in the physical space by using reverse path identification method. A dumbbell test rig was designed and manufactured so as to have a lap joint connecting the two weights placed at either ends of the bolted beam. The test structure will be modelled by both one degree of freedom lump parameter model and Finite Element model. The nonlinearities will be identified by the frequency and damping nonlinear functions in the modal space and then correlated with the equivalent laws identified by reverse path method in the physical space.