Identification of sixteen dynamic coefficients of two journal bearings from experimental unbalance responses

A method to determine all sixteen linear dynamic coefficients of two journal bearings from two or more sets of unbalance responses is proposed. The displacement responses under trial unbalance are transferred to the frequency domain, from which a linear estimator for all coefficients is developed based on the least-square estimation. The unbalance method can be conveniently applied to estimate the coefficients of large journal bearings, without relying on expensive excitation equipment to apply a large dynamic force to the rotor as required by other methods. The method is thoroughly tested by the experiments on a bearing test rig. The estimated coefficients of two journal bearings from the experimental unbalance responses correlate well with the theory. © 1994.