Residual Thermal Stresses Simulation of Television Panel in the Forming Process. Part 1: Modelling

Abstract

Internal residual stresses in glass-pressed components such as television panel are mainly frozen in thermal stresses because of inhomogeneous cooling when surface layers stiffen sooner than the core region as in free quenching. Additional factors in pressing are the effects of melt pressure history and mechanical restraints of the mould. The solidification of a molten layer of glass between cooled parallel plates is used to model the mechanics of the buildup of residual stresses in the pressing process. Flow effects are neglected, and a thermorheologically simple thermoviscoelastic material model is assumed. The equilibrium thermomechanical properties of the material and the shift function can be temperature- and pressure-dependent. The finite-element method employed in the numerical simulation is based on the theory of shells, as an assembly of flat elements. The approach allows the prediction of residual deformations and residual stresses layer by layer like a truly three-dimensional calculation while reducing the computational cost significantly.

Keywords

television panel residual stresses thermorheologically simple numerical simulation

Get full access to this article

View all access options for this article.

References

Zhou

H. M.

Feng

Geng

D. Q.

Residual thermal stresses simulation of TV panel in the forming process. Part 2: Simulations and validation. Proc. IMechE. Part C: J. Mechanical Engineering Science, 2006, 220(C5), 583–591.

Humpherys

C. E.

Mathematical modelling of glass flow during a pressing operation. PhD Thesis, University of Sheffield, 1991.

Leaderman

Viscoelasticity phenomena in amorphous high polymeric systems. In Rheology (Ed. Etrich

F. R.

) 1958, ch. 1, vol. 2, pp. 1–61 (Academic Press, New York).

Schwarzl

Staverman

A. J.

Time-temperature dependence of linear viscoelastic behavior. Appl. Phys., 1952, 23 (8), 838–843.

Gurtin

M. E.

Sternberg

G. E.

Further study of thermal stresses in viscoelastic materials with temperature-dependent properties. Second-order effects in elasticity, plasticity and fluid dynamics, International Symposium, Haifa, Israel, 1962, pp. 51–76 (Jerusalem Academic Press, Jerusalem).

Lee

E. H.

Rogers

T. G.

Solution of stress analysis problems for linear viscoelastic materials based on measured deformation functions. ASME Trans. J. Appl. Mech., 1963, 30, 127–133.

Lee

E. H.

Rogers

T. G.

On the generation of residual stresses in thermoviscoelastic bodies. ASME Trans. J. Appl. Mech., 1965, 32, 874–880.

Narayanaswamy

O. S.

Gardon

Calculation of residual stresses in glass. J. Am. Ceram. Soc., 1969, 52 (10), 554–558.

Aggarwala

B. D.

Saibel

Tempering stress in circular plates and cylinders. J. Math. Phys. Sci., 1968, 2, 321–332.

10.

Dumora

Saisse

Knosp

Goudeau

Licht

Thermal tempering study of glass insulators by means of a finite element modellization. Indian Ceram. Soc., 1986, 3, 151–160.

11.

Chabrand

Licht

Maisonneuve

Raous

Residual thermal tempering stresses. Comp. Struct., 1989, 31 (6), 1003–1011.

12.

Mauch

Jackle

Thermoviscoelastic theory of freezing of stress and strain in a symmetrically cooled infinite glass plate. J. Non-Cryst. Solids, 1994, 170 (1), 73–86.

13.

Daudeville

Carre

Thermal tempering simulation of glass plates: Inner and edge residual stresses. J. Therm. Stresses, 1998, 21 (6), 667–689.

14.

Daudeville

Bernard

Residual stresses near holes in tempered glass plates. Mater. Sci. Forum, 2002, 404–407, 43–48.

15.

Bushko

W. C.

Stokes

V. K.

Solidification of thermoviscoelastic melts. Part 1: Formulation of model problem. Polym. Eng. Sci., 1995, 35 (4), 351–364.

16.

Lee

Y. B.

Kwon

T. H.

Yoon

Numerical prediction of residual stresses and birefringence in injection/compression molded center-gated disk. Part 1: Basic modeling and results for injection molding. Polym. Eng. Sci., 2002, 42 (11), 2246–2272.

17.

Lee

Y. B.

Kwon

T. H.

Yoon

Numerical prediction of residual stresses and birefringence in injection/compression molded center-gated disk. Part 2: Effects of processing conditions. Polym. Eng. Sci., 2002, 42 (11), 2273–2292.

18.

Kamal

M. R.

Lai-Fook

R. L.

Hernandez-Aguilar

J. R.

Residual thermal stresses in injection moldings of thermoplastics: A theoretical experimental study. Polym. Eng. Sci., 2002, 42 (5), 1098–1114.