EXPERIMENTAL IDENTIFICATION OF NONLINEAR JOINT MODELS: APPLICATION TO AUTOMOTIVE HEADLAMPS
Abstract
The work presented deals the dynamic and vibration behavior of automotive headlamps. Some vibration tests have exhibited nonlinear behavior of these optical systems regarding the excitation amplitude and/or the direction of the frequency sweep. The causes of these nonlinear phenomena can be a priori attributed to the joints that connect the reflector part to the housing part. The types of nonlinearities considered are: stick-slip, clearance, friction.
An experimental analysis is conducted to identify the models that are the most suitable to predict the joints dynamic behavior. A specific test rig has been designed. Three different joints are considered, they are subjected to a forced alternated displacement. The force – displacement curves obtained are analyzed versus the amplitude and the frequency of the imposed displacement. Then the parameters for the models are estimated concerning: the Masing model, the Kelvin Voigt and a spring with two stop ends. Some dependency is observed with respect to the frequency. The results are discussed and future work orientations are given.