Modal Analysis of an Aircraft Fuselage Panel using Experimental and Finite-Element Techniques

摘要

The application of Electro-Optic Holography (EOH) for measuring the center bay vibration modes of an aircraft fuselage panel under forced excitation is presented. The requirement of free-free panel boundary conditions made the acquisition of quantitative EOH data challenging since large scale rigid body motions corrupted measurements of the high frequency vibrations of interest. Image processing routines designed to minimize effects of large scale motions were applied to successfully resurrect quantitative EOH vibrational amplitude measurements from extremely noisy data. EOH and Scanning Laser Doppler Vibrometry (SLDV) results have been used to validate and update finite element models of the fuselage panel. Various modeling techniques were evaluated for the characterization of the panel normal modes at frequencies up to 1000 Hz. These models are briefly described, and comparisons between computational predictions and experimental measurements are presented.