FINITE-ELEMENT MODEL UPDATING USING FREQUENCY-RESPONSE FUNCTION DATA .1. THEORY AND INITIAL INVESTIGATION

This work outlines the basic formulation for the frequency response fu nction based updating method and discusses several possible solution s trategies. Using simulated experimental data, systematic studies are c onducted in the case of a simple beam structure to investigate the uni queness of the updated model, the effectiveness of the technique in th e case of noisy and incomplete experimental data, the importance of ex citation direction and the implications of co-ordinate mismatch. Numer ical aspects such as stability and convergence are also studied in som e detail. Finally, the basic algorithm is extended to deal with comple x FRF data and the updating of a proportional damping matrix is attemp ted using experimentally-measured FRF data. A number of difficulties a re identified and possible remedies are suggested.