Influence of nonlinear damping on dynamics of mechanical system with a pendulum

Investigations of regular and chaotic vibrations of the autoparametric system suspended on a nonlinear coil spring and a magnetorheological damper are presented in the paper. Application of a semi-active damper together with the nonlinear spring allows controlling the dangerous motion and additionally gives new possibilities for designers. The investigations are curried out close to the main parametric resonance in the neighbourhood of the instability region which can appear inside the resonance. Obtained results show that the semiactive suspension may reduce dangerous motion and it also allows to maintain the pendulum at a given attractor or to jump to another one.