Investigation of Unbalanced Mass of a Work Roll in a Cold Rolling Mill

냉간 압연기에서 작업롤의 질량 불평형에 관한 연구

  • Kim, Young-Deuk (Dept. of Mechanical Engineering, Pohang University of Science and Technology (POSTECH)) ;
  • Kim, Chang-Wan (School of Mechanical Engineering, Konkuk Univ.) ;
  • Park, Hyun-Chul (Dept. of Mechanical Engineering, Pohang University of Science and Technology (POSTECH))
  • 김영득 (포항공과대학교 기계공학과) ;
  • 김창완 (건국대학교 기계설계학과) ;
  • 박현철 (포항공과대학교 기계공학과)
  • Received : 2011.10.18
  • Accepted : 2012.01.26
  • Published : 2012.04.01


An abrasion due to continuous friction between a work roll and strip causes the mass of the work roll to be unbalanced in the rolling process. We developed a mathematical model for the rolling mill considering the unbalanced mass and verified the model experimentally. The work roll was approximated as a rigid rotor with eccentricity, and the effect of the unbalanced mass on chatter vibration was investigated. The joint forces computed by quasistatic analysis were applied to the work roll in the rolling mill. Transient responses were obtained, and frequency analysis was performed by solving equations of motion using a direct integration method. Horizontal vibrations were more strongly affected by eccentricity than vertical vibrations. In the horizontal direction, a small eccentricity of 1% of the work roll radius considerably increased the amplitude of the chatter frequency.


Supported by : POSCO 기술연구소, 한국연구재단


  1. Lee, C., 1999, The study on chatter mechanism and friction induced self-excited vibration in the rolling system, Master's thesis, Department of Iron & Steel Technology, Graduate School of Iron & Steel echnology: Pohang University of Science and Technology, pp.6-16.
  2. Jun, H., Lee, J. and Lee, S., 1995, "Chatter Vibration in Hot Strip Finishing Mills," Trans. of the KSME (A), Vol. 35, No. 5, pp. 414-426.
  3. Son, B., Roh, Y. and Lee, Y., 1994, "The Cause of Vibration at Finishing Stands in a Hot Strip Mill," Korean Society for Noise and Vibration Engineering, Vol. 4(1), pp. 43-50.
  4. Mehrabi, R., Silani, M., Ziaei-Rad, S., Salimi, M. and Kamranian, A., 2008, "Investigation of Influences of Operational Parameters on Chatter Vibration of Cold Rolling Machines Using Finite Element Method," Metal Forming, Vol. 1, pp. 467-474.
  5. Johnson, R.E. and Qi, Q., 1994, "Chatter Dynamics in Sheet Rolling," Int. d. Mech. Sci.,Vol. 36(7), pp. 617-630.
  6. Swiatoniowski, A. and Bar, A., 2003, "Parametrical Excitement Vibration in Tandem Mills-Mathematical Model and Its Analysis," J. Mater. Process. Technol. Vol. 134(2), pp. 214-224.
  7. Bar, A. and Swiatoniowski, A., 2004, "Interdependence Between the Rolling Speed and Non-Linear Vibrations of the Mill System," J. Mater. Process. Technol. Vol. 155-156, pp. 2116-2121.
  8. Ginzburg, V. B. and Ballas, R., 2000, Flat Rolling Fundamentals, MARCEL DEKKER, pp. 381-387.
  9. Kim, Y., Park, H., Lee, S. and Kim, C., 2011, "Development of a Mathematical Model for the Prediction of Vibration in a Cold Rolling Mill Including the Driving System," ISIJ International, accepted.
  10. Kim, J. S., 2003, A Study on the Active Balancing System for High-Speed Rotating Machinery, Doctor's Thesis, Department of Mechanical Engineering, The Graduate School of Ajou University, Suwon, pp. 13-17.
  11. Theodossiades, S. and Natsiavas, S., 2000, "Non-Linear Dynamics of Gear-Pair Systems with Periodic Stiffness and Backlash," Journal of Sound and Vibration, Vol. 229, pp. 287-310.
  12. Theodossiades, S. and Natsiavas, S., 2001, "Periodic and Chaotic Dynamics of Motor-Driven Gear-Pair Systems with Backlash," Chaos, Solitons & Fractals Vol. 12, pp. 2427-2440.
  13. Craig Jr., R.R. and Kurdila, A.J., 2006, Fundamentals of Structural Dynamics., JOHN WILEY & SONS, INC., pp. 500-514.
  14. Bathe, K., 1996, Finite Element Procedures, Prentice Hall, pp.768-782.