Minimum Weight Design of a Rotor Bearing System With Multiple Frequency Constraints

The objective of the present study is to develop an efficient design algorithm for minimum weight design of a rotor bearing system under the requirements of operational speed range, i.e., multiple frequency constraints, to increase the performance of an existent rotor system. The system is modeled as an assemblage of rigid disks, shaft elements with distributed mass and stiffness, and discrete bearings. The system design variables are the inner radius of shaft elements and the stiffnesses of bearings. The optimization techniques employed to compare the results are method of exterior penalty function, method of feasible directions, and method of modified feasible directions. The parameter sensitivity analysis of the system is also presented. Three examples are used to demonstrate the merits of the design algorithm. The results indicate that the weight of the rotor bearing system can be significantly reduced at the optimum stage.