Hybrid modal damping identification for bladed disks and blisks

Abstract

Current damping identification methodologies typically require measurements of complex eigenvalues, complex eigenvectors, and the applied force. Also, these methods can be sensitive to measurement noise. Most importantly, only a few current methods can be used for regions of high modal density. Thus, the work herein utilizes the frequency response of a system to identify modal damping in regions of (low and) high modal density. This method does not require knowledge of the absolute forcing, rather only the relative forcing is needed. Results are presented for a mistuned blisk, and the proposed method is compared with an alternative damping identification technique.