LAUSR

The location of bifurcation points and bifurcation diagrams is important for the understanding of a nonlinear system with parametric resonance. This paper presents a model-less method to predict bifurcations of slightly damped multi-degree-of-freedom nonlinear systems with parametric resonance using transient recovery data in the pre-bifurcation regime. This method is based on the observation that the envelope amplitude of a decaying response in the pre-bifurcation regime recovers more slowly to the equilibrium as the system becomes closer to the bifurcation. Data obtained from both simulations and experiments are used to forecast the location of the bifurcation point and the bifurcation diagram. Forecasting results demonstrate that the method can be used to predict the bifurcation accurately under a set of specific assumptions.