Increased reliability of reference-based damage identification techniques by using output-only data

During the past few years, a considerable number of damage identification techniques have been proposed and successfully tested on vibration data obtained from mechanical structures. Most vibration-based methods identify damage by interpreting measured changes in modal parameters. In practice, damage identification problems can occur due to minor changes in the boundary conditions of the test setup especially if classic input-output vibration measurements are required for the diagnosis of a lightweight structure. In this contribution, a comparison is made between an input-output and output-only damage identification set-up for an aluminum beam structure suffering from fatigue-induced crack formation. (C) 2003 Elsevier Ltd. All rights reserved.