Control-based continuation for investigating nonlinear experiments

This paper presents a systematic experimental study of two one-degree-of-freedom nonlinear devices using the newly introduced control-based continuation method by Sieber and Krauskopf [Nonlinear Dynamics 2008]. By considering hardening, softening and bistable spring characteristics we demonstrate the versitility and power of the control-based continuation method for investigating nonlinear experiments. We show that, using this method, it is possible to track the stable orbits of the devices through a saddle-node bifurcation (fold) where they lose stability and continue them up to the resonance peak where they undergo a second saddle-node bifurcation. For the bistable case, a bifurcation diagram is produced that is strongly reminiscent of the bifurcation diagram produced using the classical harmonic balance solution. A detailed introduction to general continuation methods is included to enable implementation by other experimentalists.