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 set-up 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.