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An Efficient Method for Mold Thermal Cycle Analysis in Repeated Forming Process of TV Glass

TV 유리의 반복 성형공정에서 금형 열사이클 해석을 위한 효과적 방법

  • 최주호 (한국항공대학교 항공우주 및 기계공학부) ;
  • 김준범 (삼성코닝(주)) ;
  • 황정해 (한국항공대학교 항공우주 및 기계공학부) ;
  • 하덕식 (삼성코닝(주))
  • Published : 2000.09.01

Abstract

An efficient method is developed for plunger thermal cycle analysis in repeated forming process of the TV glass. The plunger undergoes temperature fluctuation during a cycle due to the repeated contact and separation from the glass, which attains a cyclic steady state having same temperature history at every cycle. Straightforward analysis of this problem brings about more than 80 cycles to get reasonable solution, and yet hard to setup stopping criteria due to extremely slow convergence. An exponential fitting method is proposed to overcome the difficulty, which finds exponential function to best approximate temperature values of 3 consecutive cycles, and new cycle is restarted with the fitted value at infinite time. Numerical implementation shows that it reduces the number of cycles dramatically to only 6-18 cycles to reach convergence within 10 accuracy. A system for the analysis is constructed, in which the thermal analysis is performed by commercial software ANSYS, and the fitting of the result is done by IMSL library. From the parametric studies, one reveals some important facts that although the plunger cooling or the glass thickness is increased, its counter part in contact is not much affected, duo to the low thermal conductance of the glass.

Keywords

References

  1. McGraw, D. A., 1961, 'Transfer of Heat in Glass During Forming,' Journal of The American Ceramic Society, Vol. 44(7), pp. 353-363 https://doi.org/10.1111/j.1151-2916.1961.tb15921.x
  2. Manthuruthil, J., Sikri, T.R. and Simmons, G.A., 1974. 'Simplified Mathematical Model Simulating Heat Transfer Glass-Forming Molds,' Journal of The American Ceramic Society, Vol. 57(8), pp. 345-350 https://doi.org/10.1111/j.1151-2916.1974.tb10919.x
  3. Bonacina, C., Strada, M. and Gottardi, V., 1982, 'Finite Element Analysis of the Temperature Fields in Glass Molds,' Glass Technology, Vol. 23(4), pp. 172-176
  4. Davey, K. and Hinduja, S., 1990, 'Modelling the Transient Thermal Behavior of the Pressure Die-Casting Process with the BEM,' Applied Mathematical Modelling, Vol. 14, pp. 395-409 https://doi.org/10.1016/0307-904X(90)90095-M
  5. Holman, J.P., 1976, Heat Transfer, McGraw-Hill
  6. Fellows, C. J. and Shaw, F., 1978, 'A Laboratory Investigation of Glass to Mould Heat Transfer During Pressing,' Glass Technology, Vol. 19(1), pp. 4-9
  7. ANSYS Thermal Analysis Guide Release 5.5, 1998, SASI IP, Inc.
  8. IMSL On-Line Pdf Documentation, 1997, Visual Numerics, Inc.