Effects of Ray Bending in Scattered Light Photoelasticity for Tempered and Annealed Glass Plates

Abstract:

Residual stresses in tempered glass plates can be measured with the scattered light method. Usually a rectilinear propagation of light is assumed. However, due to the gradients of the refractive index, the light rays curve. We have experimentally demonstrated this for tempered (surface stress 120 MPa and more) and annealed glass plates. For a laser beam of finite width this also results in broadening and loss of photoelastic modulation. While some features of the experimental picture (dependence of the period of modulation on depth), can be captured in the simple model of rectilinear propagation, the other observations need development of more elaborated models.

• Periodical: Applied Mechanics and Materials (Volume 70)
• Pages: 440-445
• DOI: https://doi.org/10.4028/www.scientific.net/AMM.70.440
• Online since: August 2011
• Authors: Siim Hödemann, Jaak Kikas, Hillar Aben, Johan Anton, Andrei Errapart
• Keywords: Glass, High Tempering, Scattered Light Photoelasicity

References

[1] Aben, H. and Guillemet, C. (1993) Photoelasticity of Glass. Springer-Verlag, Berlin.

[2] Lochegnies, D., Romero, E., Anton, J., Errapart, A. and Aben, H. Measurement of complete residual stress fields in tempered glass plates. In Proc. International Conference Glass Processing Days 2005,. Tampere, Finland, 2005, 88–91.

DOI: 10.1111/j.1475-1305.2008.00422.x

[3] H. Aben, J. Anton, A. Errapart, S. Hödemann, J. Kikas, H. Klaassen, M. Lamp. On non-destructive residual stress measurement in glass panels. Estonian J. Eng., 2010, 16, 150-156.

DOI: 10.3176/eng.2010.2.04

[4] Aben, H.; Josepson, J. (1995). On the precision of integrated photoelasticity for hollow glassware. Optics and Lasers in Engineering, 22(2), 121 - 135.

DOI: 10.1016/0143-8166(94)00019-7

[5] Dolovich, A., Wang, Z. and Gladwell, G.M.L., An iterative approach to curved ray reconstruction of birefringent fields, Optics and Lasers in Engineering 22 (1995) 347-372.

DOI: 10.1016/0143-8166(94)00034-8

[6] R. Weller, J. K. Bussey: Photoelastic analysis of three-dimensional stress systems using scattered light, National Advisory Committee for Aeronautics, Washington, (1939).

[7] I. Hundhammer, A. Lenhart , D. Pontasch, R. Weissmann: Stress measurement in transparent materials using scattered laser light, Glass Sci. Technol. 75 No. 5, (2002).

[8] S. Bateson, J.W. Hunt, D. A. Dalby: Stress measurement in tempered glass plates by scattered light method with a laser source, Ceram. Bull. 45, (1966).