Comparison of Critical Speeds of a Rotor System with Different Types of Finite Elements

The critical speeds of all kinds of high-speed rotors must be calculated in project so that all rotors can work in the safe range of speeds and avoid resonance. A single-span-two-disc rotor system is investigated by using finite element method based on ANSYS. Natural frequencies are calculated by using beam, solid, mass, shell, beam-solid, beam-shell elements and critical speeds are obtained from Campbell diagram. Finally, the first and second critical speeds are measured by a test rig. Comparison of theoretical and experimental results is performed to assess the accuracy of different element combining forms.