Monday  |  Salon 14  |  04:50 PM–05:10 PM

#16523–Advancing Secondary Resonance Characterization in Nonlinear Systems via Phase-Locked-Loop Testing

Nonlinear systems exhibit unique dynamical characteristics such as super- and sub-harmonic resonances. This study presents a novel vibration testing method that employs control techniques to automatically and systematically characterize these secondary resonances. The proposed method combines phase-locked-loop (PLL) feedback control with adaptive filters capable of online Fourier decomposition. By exploiting the phase properties at the desired harmonic order, the control objective is designed to identify the sought resonances. Numerical simulations and experimental tests are conducted to demonstrate the effectiveness of this approach in detecting super-harmonic responses, which often display instabilities and bifurcations, as well as sub-harmonic isolated responses that are detached from the main branch. Specifically, starting from an initial condition at rest, the use of PLL facilitates a smooth state transfer toward one resonance point of a sub-harmonic isolated response. Compared to conventional testing methods, PLL provides more insights into the advanced dynamics nonlinear systems can exhibit.

Tong Zhou   University of Liege
Gaëtan Kerschen   University of Liege