A novel method based on Taguchi's method was proposed for tolerance design for rotor system dynamics. It reduces structural dynamic response variation of rotor system due to uncertainties of design parameters and assembly process

by tolerance design of manufacturing and assembly parameters. The approach was performed by the following steps:(1) Design parameters through orthogonal array experiments and ANOVA(analysis of variance)

initially determining level combination of design parameters meeting design requirements;(2) Determine initial nominal value and range of design parameters for tolerance design

set up objective function and form multi-objective optimization;(3) Solve the multi-objective optimization problem by genetic algorithm and get the tolerance design results. A tolerance design of initial unbalanced discs assembly for a twin-spool aero-engine was carried out. The results show that bearing vibration response can be decreased by matching of initial unbalance amplitude and phase angle differences

and qualified rate of maximum bearing vibration response is increased from 17.7% to 97%

which can verify the feasibility of the method.