Gray Simmons, Andrew R. Kreshock, Robert P. Thornburgh, Martin K. Sekula, Cristina Riso
This paper investigates the amplitude-dependent characteristics of the TiltRotor Aeroelastic Stability Testbed. The recovery rate, multiple decay Prony averaging, and Stockwell transform methods are employed to account for system nonlinearities, which are neglected by conventional test data analysis methods based on linear assumptions. A comprehensive study of ground vibration and wind tunnel test data highlights reduced local damping and frequency at larger response amplitudes for various blade materials, rotor speeds, and pitch–flap coupling parameters. This study demonstrates novel analysis capabilities to investigate nonlinear dynamics in tiltrotors and support their design.