Title: Control-based nonlinear vibration testing: recent progress and current challenges
Affiliation: Space Structures and Systems Laboratory, Aerospace and Mechanical Engineering Department, University of Liège, Belgium
Abstract
In the virtual prototyping era, it remains crucial to validate the simulation results using experimental tests. In this context, experimental modal analysis (EMA) continues to be the dominant structural dynamics method used in aerospace, civil and mechanical engineering. However, one important assumption at the root of EMA is that the structural system behaves linearly. The objective of this presentation is to discuss the recent developments in the area of control-based nonlinear vibration testing (CBNVT). Unlike current open-loop testing methodologies, CBNVT proposes a change in paradigm by operating the experiment in a closed loop. Specifically, it combines (i) feedback control to stabilize unstable orbits and (ii) path following techniques to explore - in a systematic and effective manner - the dynamics of the system directly during the experiment, i.e., without the need for a mathematical model of the system. We will also introduce a new CBNVT algorithm relying on a fully online and derivative-less experimental arclength continuation method. The algorithm will be demonstrated using both numerical simulations and experimental measurements.
Short bio
Gaëtan Kerschen completed his Ph.D. degree in Aerospace Engineering from the University of Liège in Belgium in 2003. In 2003 and 2004, he was a visiting postdoctoral fellow at National Technical University of Athens and at the University of Illinois at Urbana-Champaign. Since 2007, he has been a faculty member at the University of Liège, where he is a professor in the Department of Aerospace and Mechanical Engineering. His expertise is primarily in the area of structural dynamics with a focus on the nonlinear dynamics of aerospace structures. He is the recipient of two European Research Council (ERC) grants, namely an ERC Starting Grant and an ERC Proof of Concept Grant. He is the co-founder of NOLISYS, a startup company which provides solutions and software for nonlinear vibrating systems.