ENTIRE · Experimental Continuation in Nonlinear Dynamics: Aerospace Engineering and Beyond

Nonlinear vibration theory witnessed extraordinary advances during the 20th century following Poincaré’s seminal work. Since the 1970s, impressive progress has been made in computational nonlinear dynamics with the development of nonlinear finite element methods and numerical continuation. Although not all challenges have been overcome yet, the theoretical understanding of nonlinear dynamical phenomena and their prediction using numerical models have reached a high level of maturity. Surprisingly, this progress has not significantly impacted engineering practice. Specifically, vibration testing in industry remains grounded in the assumption of linearity. Yet, under the rising pressure of high-performance and carbon-neutral designs, aerospace structures exploit advanced materials and are increasingly lighter and more flexible, with the consequence that nonlinearity is now ubiquitous. To fill the existing gap, a vibration testing strategy which can uncover the sometimes dangerous, sometimes beneficial nonlinear dynamics of engineering structures is urgently needed. The ENTIRE project proposes to leverage feedback control to pioneer a novel methodology able to identify experimentally - in a model-free, real-time and stability-guaranteed manner - the entire bifurcation diagram of a nonlinear system. This control-based method will be complemented by a data-driven, machine-learning-based approach. The potential of our developments will be demonstrated using real-life aerospace applications including turbojet engine components and a full-scale aircraft. Given the generic character of our methodology, applications in other areas of science and engineering will also be envisioned, e.g., in microresonators and in dress of physics such as optics. Eventually, ENTIRE will develop the first complete experimental counterpart to numerical continuation, hence leading to full mastery of the three facets of nonlinear vibration analysis, namely theory, simulation and testing.