Experimental study of the variation of tie-bolt fastened rotor critical speeds with tighten force

In order to investigate the variations of the critical speeds of the tie-bolted rotor with tighten force, the tighten force test rig is established, and the variation of the tighten force with torque is measured. A model tie-bolt fastened rotor is designed and manufactured, and the test platform for rotor dynamics is established. The dynamical responses of the tie-bolted rotor are measured under different tighten forces. According to the dynamical responses under five different tighten torques, the first two critical speeds of the model tie-bolted rotor are obtained, and the variations of critical speeds are analyzed. The experimental results are compared with the theoretical simulation results, showing that the first two critical speeds of the tie-bolted rotor increase as the tighten force increases while either speeding up or slowing down. Comparison with theoretical analysis shows that the critical speeds of the simulation are close to those of the experimental results, while the theoretical model still requires some improvement to better illustrate the influence of the tighten force on critical speeds.