Study on modal flexibility and sensitivity to parameters in the main drive system of rolling mill

Torsional vibration is universal in the main drive system of rolling mill. In this paper, the spring-mass system dynamic model describing torsional vibration is built, and proved to be feasible through comparing the first-order natural frequency with the experimental result. On the basis of the validated model, the modal energy and flexibility distribution is analyzed and the results indicate that the system energy is mainly centralized at the first-order mode, which is easily excited and most frequently observed in the actual rolling process. Moreover, the system sensitivity to the moment of inertia and the torsional stiffness is analyzed, and the best way modifying system parameters to modulate the natural frequencies is studied. All these conclusions are significant to structure design, parameter optimization and vibration control for the mill drive system.