Nonlinear Dynamic Analysis of a Parametrically Excited Cold Rolling Mill

Abstract

In this work, a four high cold rolling mill is modeled as a spring-mass-damper system considering horizontally and vertically applied time-dependent forces due to the interac tion between the strip and the working rolls. The effect of vibration of the moving strip on the work roll vibration is also considered for developing the governing equation of motion o f the system which is found to be that of a nonlinear parametrically excited sys tem. The governing equation of motion is solved by using the method of multiple scales to find the instability regions and frequency-response curves of the system. The critical am plitude of horizontal load in roll bite is calculated and the frequency-response is studied in detail considering the effect of various process parameters, such as velocity, thickness of strip, time delay, amplitude, arid frequency of horizontal load in roll bite. This work can find application in the design and development of high speed and chatter free rolling mills.

Experimental and Numerical Investigation on the Roll System Swing Vibration Characteristics of a Hot Rolling Mill

“…[9][10][11][12] The structural dynamic model became more and more comprehensively from the singledimensional linear vibration model to multi-dimensional nonlinear coupled vibration model. These models were built by using the centralized mass method which neglected the axis asymmetrical factors of roll body.…”

“…(11) illustrates that the influence of the horizontal force increment ΔP x and the periodic meshing impact ΔF x , ΔF z generated by the ATG are the main factors which affect the roll system stability.…”

Quasi-Periodic Oscillations of Roll System in Corrugated Rolling Mill in Resonance

“…Yarita et al [3] proposed a twodegree-of-freedom vertical vibration system and studied the parameter excited resonance by analyzed the fluctuating variation of stiffness between rollers. Kapil et al [4] developed a nonlinear parameter excited vibration single-degree of freedom model of the rolling mill and obtained the amplitude-frequency vibration characteristics and unstable region of the rolling mill. Li and Wen [5] established a nonlinear vibration mechanical model by considering the clearance and vibration boundary of the main drive system of the rolling mill and investigated various dynamic responses such as periodic, quasi-periodic and chaotic vibrations.…”

Stability Analysis of a Nonlinear Coupled Vibration Model in a Tandem Cold Rolling Mill

“…For most vertical vibration models, the mill stand was modeled with multiple degrees of freedom. Kapil et al [7] used the further simplified structure model to analyze the frequency response in detail. Kimura et al [8,9] and Heidari et al [10][11][12][13] illustrated the influence of lubrication characteristic on mill chatter.…”