FINITE DIFFERENCE FORMULATION FOR MODAL PARAMETER ESTIMATION

This paper deals with a new finite difference method for modal parameter estimation. This method uses formulas which involve differences between the frequency response data at three frequencies in the vicinity of a natural frequency to estimate this natural frequency together with the damping and the residue. Compared with the two-point finite difference method, tests with both analytical and experimental frequency response data with not well-separated modes show better estimations when using the three-point difference method.