A non-probabilistic-interval analysis method

which solves the rotordynamics with these uncertain parameters

was presented.Based on interval mathematics and perturbation method

interval analysis method simplified the uncertain parameters such as support stiffness and connecting structure stiffness to interval vectors

so that it could get the intervals within which the rotordynamics varied when less information of structure was known.The formulation of natural frequencies of rotor using interval perturbation analysis method was formulated.A numerical example of comparison between interval perturbation method analysis and monotonic method was given.The rotordynamic analysis of a turbofan rotor was performed with this method.The present interval perturbation method is more accurate than determined method in rotordynamic analysis

and it decreases the requirement of uncertain parameters

such as distribution characteristic.