SPATIAL DOMAIN MODAL-ANALYSIS OF LIGHTLY-DAMPED STRUCTURES USING LASER VELOCIMETERS

Traditional modal identification techniques do not take advantage of t he high spatial density of scanning Laser Doppler Velocimeter (LDV) me asurements. In this paper, a spatial modal parameter estimation techni que, specially adapted for use with LDV measurements, is presented. It is based on a real-mode modal filtering concept and, therefore, is ap plicable to structures with low damping. From the estimated mode shape surfaces, curve-fitted with two-dimensional Fourier series, angular d isplacements are calculated. A rectangular plate example illustrates t he proposed techniques with both numerically simulated and experimenta l results.