Prediction of the dynamic behavior of a non-linear structure with a dry friction

Certain mechanical industrial structures are characterized by a local non-linear behavior. The study of this type of structure must be effectuated with an iterative method and by taking into account the presence of localised non-linearities. In this article, we propose a method for analyzing the non-linear forced response of a dry fiction damped system and we compare the analytical predictions with experimental results. Two types of non-linear elements are considered (a non-linear support and a friction element). The support is characterised by non-linear parameters of stiffness and damping. The friction element characterizes the dry friction between surfaces and is modelled with an equivalent viscous damping coefficients. We consider a non-linear formulation based on the exploitation of eigensolutions of the associated conservative linear system and the non-linear characteristics. The iterative Newton-Raphson method will be used in order to solve the non-linear algebraic system of equations and to obtain the frequency responses of the structure. Finally, we propose a numerical simulation applied to a non-linear mechanical system with an imposed amplitude of excitation. The experimental system and associated data acquisition system will be described.