Abstract
The present work focuses on multi-objective optimization of rotors design described by discrete variables. The aim is to modify the design of a rotor in order to avoid some resonance frequencies. The multi-objective optimization problem consists: on the one hand, in minimizing the total mass of the rotor, and on the other hand, in shifting the critical speeds to avoid the operating frequency of the rotor. The design variables are the diameters of the shaft sections that are assumed to be available only in a set of pre-specified values. To solve the discrete rotor design problem, a Multi-Objective Genetic Algorithm (MOGA) is used. A 88 degrees of freedom model of a rotor is considered as a numerical example. In order to select optimal values of MOGA control parameters, a set of numerical experiments are carry out where crossover and mutation rates are varied. The results of optimal designs of the rotor are reasonable solutions each of which satisfies the objectives at an acceptable level without being dominated by any other solution.