BIAS IN MODAL PARAMETERS USING THE DIRECT AND ITERATIVE RFP IDENTIFICATION PROCEDURES

In the rational fraction polynomial method [1] the identification of m odal parameters is obtained through a direct linear least-square optim ization technique but a particular form of fitting error is minimized. An iterative algorithm has been recently developed which uses the tru e fitting error [2]. In this paper a statistical analysis is developed to estimate the bias effects on the identified parameters when the da ta are polluted with noise. Both the direct and iterative procedures a re considered. Numerical simulations are used to validate the results predicted by the theoretical analysis, which shows that the iterative approach is by far more efficient than the direct method.