Modal Analysis on a Schematic Aerospace Structure: FEM Simulation and Experimental Updating

Ground Vibration Tests on modern aircraft structures play a key role for the aeroelastic certification of new airplanes. The dynamic model of an aircraft is essential for flutter predictions and/or for analytical structural model updating and validation. This paper describes a technique aimed to the reliability and accuracy improvement of the numerical modal analysis by means of an experimental dynamic model. The procedure described hereby consists of a finite element analysis of a schematic aerospace structure, a GVT (both Phase Separation and Resonance techniques) and the FE model updating based on the knowledge of the experimental FRFs and natural frequencies. The results show that this procedure allows an effective reduction of the discrepancies between experimental and numerical estimations.