A non-probabilistic interval analysis method was presented to solve the rotordynamics with these uncertain parameters.Based on interval mathematics and 1st step Taylor expansion method

interval analysis method simplified the uncertain parameters such as support stiffness and connecting structure stiffness to interval vectors.The formula of rotor natural frequencies using interval Taylor expansion analysis method was formulated and compared with the probabilistic method.The proposed method can be used to estimate the intervals of rotordynamics requiring the intervals of uncertainties only

so it can be used to solve rotordynamics problems with uncertainties.A numerical example of comparison between Taylor expansion method and probabilistic method was given.The natural frequency regions yielded by interval Taylor expansion method are very close to the accurate ones

and the separation margin is less than 2.2% as the deviation coefficient betta is taken as 20%.A rotordynamic test rig was set up and the test result demonstrates the efficiency of interval analysis method.