Estimation of Forcing Functions on a Mistuned Bladed Rotor From Harmonic Response

Abstract

This paper deals with the estimation of forcing functions on a mistuned bladed rotor from measurements of harmonic response via Kalman filter (KF) in time domain. An unique feature of this approach is that the number of estimated variables can be far greater than the number of measurements. The robustness of this method to measurement errors is shown. It is also shown that direct prediction of amplitude and phase of sinusoidal force vector from input/output frequency response function has a large amount of errors in the presence of unavoidable measurement noise. Numerical examples contain both frequency mistuning and geometric mistuning.