Optimal weight design of rotor systems with oil-film bearings subjected to frequency constraints

The purpose of this study is to investigate optimal weight design of rotors. The analysis results of this work for dynamic analysis of rotors are compared to those available in the literature. An excellent agreement is observed, which validates the formulation and implementation of the model developed. Further analysis is conducted for rotors with oil-film bearings. The stability of the system is studied by examining the real parts of the eigenvalues and the logarithmic decrement. The sequential quadratic programming technique is used for the minimum weight design. The effect of minimum weight design on the distribution of rotor shape, weight saving, and system stability is examined. It is demonstrated that significant reduction of rotor weight can be achieved. Weight reduction of more than 80% is possible for a simple rotor analyzed, whereas for a realistic complex rotor with oil-lubricated bearings, an original rotor weight of 5.4886 kg can be reduced to 1.7267 kg after being optimized. (C) 2001 Elsevier Science B.V. All rights reserved.