Impact damper for controlling friction-driven oscillations

Control of friction-driven oscillations by using an impact damper is investigated. An experimental setup of a single degree-of-freedom friction-driven oscillator with an attached impact damper is designed and fabricated. An approximate nonlinear mathematical model of the friction-driven oscillator is derived. The values of unknown parameters in this mathematical model are obtained by using a least square error method so as to match the experimentally obtained response. An approximate solution of the general steady-state response of the friction-driven oscillator with an attached impact damper is derived analytically by using a piecewise equivalent linearization approach assuming two non-symmetric impacts per cycle. The effects of mass ratio, coefficient of restitution and clearance on the performance of the impact damper have been investigated analytically and the results are verified by numerical integration. Experimental results obtained for steel-on-steel, aluminum-on-aluminum and aluminum-on-rubber impacts are reported.