Title: Dynamic behaviour of cold rolling mill with unsteady lubrication roll-gap interface during sheet metal forming process
Authors: Qiaoyi Wang; Ze Zhang; Huiqin Chen; Changshui Feng
Addresses: School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China ' School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China ' School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China ' School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018, China
Abstract: This paper presents the results of developing a vibration model for the rolling mill vertical system with respect to the roll gap under the unsteady lubrication conditions to address the frequently self-excited vibration phenomenon of rolling mill vertical systems. On the basis of rolling theory, hydromechanics theory, lubrication and friction theory, as well as mechanical vibration theory, the interfacial film constrained multiple coupling model consisting of the friction lubrication model of interface, the rolling force model and the motion model of work rolls was applied as the vibration model. The self-excited vibration of the 1,850 cold rolling mill was simulated using MATLAB. The effects of some main parameters on the critical speed and amplitude for vertical vibrations were analysed quantitatively. The results show that the critical speed of the vibration is negatively related to the rolling lubricant viscosity. It was found that the critical speed is positively related to the surface roughness of work roll and strip, the positive damping of rolling mill vertical system. The findings of this research would help related practitioners to control the vibration of rolling mills.
Keywords: sheet metal forming; cold rolling mills; dynamic behaviour; roll-gap interface; unsteady lubrication; vibration modelling; friction lubrication; rolling force; work roll motion; work rolls; self-excited vibration; simulation; lubricant viscosity; critical speed; surface roughness; positive damping.
International Journal of Surface Science and Engineering, 2015 Vol.9 No.4, pp.343 - 358
Received: 25 Mar 2014
Accepted: 19 May 2014
Published online: 27 Jul 2015 *