Energy Dissipation in an Assembly with Planar Contact
Résumé
Damping remains the biggest challenge in structural dynamics, especially when it is caused by friction in joints. This work aims at highlighting transient phenomena during partial sliding in joints and quantifying nonlinear dynamic properties in terms of frequency and Loss Factor. To achieve this, a SDOF model based on the modal projection of a continuous beam model has been developed. This assumption permits computing normal and tangential stress and strain fields in joints. These results are used to define dissipative energy and force. A semi-analytical solution is presented in order to compute the free first vibration-mode of the beam. The numerical results first emphasize a displacement-dependent nonlinear Loss Factor and, secondly, a time-varying natural frequency. Finally, signal processing tools have been developed and tested on numerical results. These tools will be useful to post process future experimental results.