Experimental and Numerical Investigation of the Vibration Characteristics in a Cold Rolling Mill Using Multibody Dynamics

Chatter vibration is detrimental to the quality of the metal strip in the rolling process. A numerical model was proposed to investigate the vibration characteristics. A rolling mill that includes the driving system was modeled by multibody dynamics to investigate the cause and characteristics of the chatter vibration. The proposed numerical model was validated by theoretical analysis and an experiment that was carried out during manufacturing. The frequency of chatter with high amplitude was in the range computed theoretically by the equation for chatter frequency. The range of chatter frequency was very similar to that predicted by the multibody dynamic analysis, if the speed range of the work roll was in steady state. Because the derivative of the chatter frequency was different from that of the gear mesh frequency (GMF), it could be claimed that the frequencies of the chatter and the gear mesh were not related. It was observed in the analysis that the GMF generated by the helical gear was transmitted to the work roll. The amplitudes of the gear mesh and chatter frequencies became high when the rolling force was high, but the chatter frequency did not occur when there was no rolling force. The effects of the speed of the work roll and the ratio between the dynamic and static components of the rolling force to the chatter vibration were also investigated. We found the chatter frequency that affects vibration of the rolling mill strongly, and analyzed the effect of the rolling parameters on chatter frequency.