Nonlinear damping in nanomechanical beam oscillator
  We investigate the impact of nonlinear damping on the dynamics of a nanomechanical doubly clamped beam. The beam is driven into nonlinear regime and the response is measured by a displacement detector. For data analysis we introduce a nonlinear damping term to Duffing equation. The experiment shows conclusively that accounting for nonlinear damping effects is needed for correct modeling of the nanomechanical resonators under study. 
Stav Zaitsev, Ronen Almog, Oleg Shtempluck, and Eyal Buks