WAVELET ANALYSIS TO CHARACTERISE NON-LINEARITIES AND PREDICT LIMIT CYCLES OF AN AEROELASTIC SYSTEM

Non-linear dynamics in aeroelastic systems are difficult to analyse and can induce unpredicted limit cycle oscillations in flight. This paper introduces wavelet analysis for processing flight data to extract information about structural non-linearities. Features and trends from wavelet transform maps of transient responses are used to detect and characterise polynomial non-linearities in stiffness. These features are also used to formulate functions that use transient responses at stable flight conditions to predict the onset of limit-cycle oscillations.