INCLUDING FOUNDATION EFFECTS ON THE VIBRATION BEHAVIOR OF ROTATING MACHINERY

Including foundation effects on rotating machinery vibrations is norma lly difficult and very approximate owing to the complicated foundation configuration and its interaction with the surrounding environment, n ecessitating experimental identification of the foundation parameters. This paper presents and evaluates numerically a promising technique f or identifying mass, damping and stiffness parameters of a field found ation supporting unbalanced rotating machinery. All necessary;measurem ents can be taken during a single run-down. Moreover, only a knowlege of the bearing characteristics and measurements of rotor and foundatio n motions at selected co-ordinates (including the connections) and at selected speeds are needed. In particular, the method does not require an accurate rotor model, nor a knowledge of the actual unbalance dist ribution.