A component damping identification method for mistuned blisks

Abstract

Different components of a structure can have different damping characteristics, and that affects the dynamic response of the overall system. Herein, we assume that damping has a simple form only at a component level. That leads to a complex damping model at a system level. A new method is introduced which identifies the component damping of a structure. This method is applied to mistuned blisks in regions of low and high modal density. The method incorporates reduced-order models, and remains accurate in the presence of measurement noise. Results are shown for a mistuned blisk with varying levels of measurement noise. The accuracy of damping identification is observed through a forced response prediction and amplification factor study. Also, a discussion on the effects of damping and stiffness mistuning on the maximum response is presented. Some differences between component and modal damping are highlighted.