Nondestructive Safety Evaluation of Thermally Tempered Glass
Publication: Journal of Materials in Civil Engineering
Volume 32, Issue 4
Abstract
Thermally tempered glass fails into small and blunt pieces upon fracture, and therefore is the product of choice when a degree of safety is required from a monolithic glass panel. The characteristic fracture pattern is the result of residual stresses in the glass that are induced during the tempering process and released during fracture. Previous research sought to correlate residual stress with the size of the fragments. In this paper, the two salient models (Barsom’s and Gulati’s) were described and validated against new experimental data. The experimental data were obtained by inducing fracture in specially prepared thermally tempered glass panels. The glass panels consisted of an unprecedented wide range of residual stress, obtained by a carefully executed thermal relaxation process. The residual stress of the specimens was measured with a scattered light polariscope that was calibrated by means of a specially devised experimental approach. It was shown that Barsom’s model is the more accurate of the two and is appropriate for predicting the fragmentation of glass with a surface residual compression larger than 60 MPa. The accuracy and precision of the scattered light polariscope were found to be ±4.7 MPa and ±3.9 MPa, respectively. The findings from this study provide a basis for a nondestructive safety evaluation of thermally tempered glass.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
Financial support from Trend Marine and EPSRC is gratefully acknowledged.
References
Acloque, P. 1956. “Deferred process in the fragmentation of tempered glass.” In Proc., IVth Int. Glass Congress, 279–291. Wuhan, China: Scientific Research Publishing.
Akeyoshi, K., and E. Kanai. 1965. “Mechanical properties of tempered glass.” In Vol. 14 of Proc., 7th Int. Glass Congress, 80–85. Wuhan, China: Scientific Research Publishing.
Anton, J. 2011. “Scattered light polariscope SCALP.” In Instruction Manual, version 5.5. Tallin, Estonia: Glasstress.
Anton, J., and H. Aben. 2003. A compact scattered light polariscope for residual stress measurement in glass plates. Tampere, Finland: Glass Processing Days.
Anton, J., A. Errapart, M. Paemurru, D. Lochegnies, S. Hodemann, and H. Aben. 2012. “On the inhomogeneity of residual stresses in tempered glass panels.” Est. J. Eng. 18 (1): 3–11. https://doi.org/10.3176/eng.2012.1.01.
ASTM. 2012. Standard specification for heat-strengthened and fully tempered flat glass. ASTM C1048. West Conshohocken, PA: ASTM.
Barsom, J. M. 1968. “Fracture of tempered glass.” J. Am. Ceram. Soc. 51 (2): 75–78. https://doi.org/10.1111/j.1151-2916.1968.tb11840.x.
CEN (European Committee for Standardization). 2004a. Glass in building: Thermally toughened soda lime silicate safety glass. I: Definition and description. EN 12150-1. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2004b. Glass in building: Thermally toughened soda lime silicate safety glass. II: Evaluation of conformity/product standard. EN 12150-2. Brussels, Belgium: CEN.
CEN (European Committee for Standardization). 2012. Glass in building. Basic soda lime silicate glass products. Float glass. BS EN 572-2. Brussels, Belgium: CEN.
Clark, A. B., and G. R. Irwin. 1966. “Crack-propagation behaviours.” Exp. Mech. 6 (6): 321–330. https://doi.org/10.1007/BF02327512.
Gulati, S. T. 1997. Frangibility of tempered soda-lime glass sheet, 72–76. Tampere, Finland: Glass Processing Days.
Haldimann, M., M. Luible, and M. Overend. 2008. Structural use of glass. Zurich, Switzerland: International Association for Bridge and Structural Engineering.
Lee, E. H., T. G. Rogers, and T. C. Woo. 1965. “Residual stresses in a glass plate cooled symmetrically from both surfaces.” J. Am. Ceram. Soc. 48 (9): 480–487. https://doi.org/10.1111/j.1151-2916.1965.tb14805.x.
Narayanaswamy, O. S. 1971. “A model of structural relaxation in glass.” J. Am. Ceram. Soc. 54 (10): 491–498. https://doi.org/10.1111/j.1151-2916.1971.tb12186.x.
Nielsen, J. H. 2009. “Tempered glass: Bolted connections and related problems.” Ph.D. thesis, Dept. of Civil Engineering, Technical Univ. of Denmark.
Nielsen, J. H. 2016. “Remaining stress-state and strain-energy in tempered glass fragments.” Glass Struct. Eng. 2 (1): 45–56. https://doi.org/10.1007/s40940-016-0036-z.
Nielsen, J. H., J. F. Olesen, P. N. Poulsen, and H. Stang. 2010a. “Finite element implementation of a glass tempering model in three dimensions.” Comput. Struct. 88 (17–18): 963–972. https://doi.org/10.1016/j.compstruc.2010.05.004.
Nielsen, J. H., J. F. Olesen, and H. Stang. 2009. “The fracture process of tempered soda-lime-silica glass.” Exp. Mech. 49 (6): 855–870. https://doi.org/10.1007/s11340-008-9200-y.
Nielsen, J. H., J. F. Olesen, and H. Stang. 2010b. “Characterization of the residual stress state in commercially fully toughened glass.” J. Mater. Civ. Eng. 22 (2): 179–185. https://doi.org/10.1061/(ASCE)0899-1561(2010)22:2(179).
Overend, M., S. De Gaetano, and M. Haldimann. 2007. “Diagnostic interpretation of glass failure.” Struct. Eng. Int. 17 (2): 151–158. https://doi.org/10.2749/101686607780680790.
Pourmoghaddam, N., M. A. Kraus, J. Schneider, and G. Siebert. 2018. “Relationship between strain energy and fracture pattern morphology of thermally tempered glass for the prediction of the 2D macro-scale fragmentation of glass.” Glass Struct. Eng. 4 (2): 257–275. https://doi.org/10.1007/s40940-018-00091-1.
Pourmoghaddam, N., and J. Schneider. 2018a. “Determination of the engine power for quenching of glass by forced convection: Simplified model and experimental validation of residual stress levels.” Glass Struct. Eng. 4 (1): 117–125. https://doi.org/10.1007/s40940-018-0078-5.
Pourmoghaddam, N., and J. Schneider. 2018b. “Experimental investigation into the fragment size of tempered glass.” Glass Struct. Eng. 3 (2): 167–181. https://doi.org/10.1007/s40940-018-0062-0.
Redner, A. S. 2002. “PC-based stress-measuring system for on-line quality control of tempered and heat strengthened glass.” In Use of glass in buildings. West Conshohocken, PA: ASTM.
Reich, S., N. Dietrich, S. Pfefferkorn, and B. Weller. 2013. “Elastic strain energy of thermally tempered glass increases its residual strength.” In Proc., Glass Performance Days, 348–352. Tampere, Finland: Glass Processing Days.
Soules, T. F., R. F. Busbey, S. M. Rekhson, A. Markovsky, and M. A. Burke. 1987. “Finite-element calculation of stresses in glass parts undergoing viscous relaxation.” J. Am. Ceram. Soc. 70 (2): 90–95. https://doi.org/10.1111/j.1151-2916.1987.tb04935.x.
Warren, P. D. 2001. “Fragmentation of thermally strengthened glass.” In Fractography of glasses and ceramics IV, 389–400. New York: Alfred.
Zaccaria, M. 2017. “Bi-tempered glass.” Ph.D. thesis, Dept. of Engineering, Univ. of Cambridge.
Zaccaria, M., and M. Overend. 2016. “Thermal healing of realistic flaws in glass.” J. Mater. Civ. Eng. 28 (2): 04015127. https://doi.org/10.1061/(ASCE)MT.1943-5533.0001421.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 32 • Issue 4 • April 2020
Copyright
©2020 American Society of Civil Engineers.
History
Received: Feb 6, 2019
Accepted: Aug 26, 2019
Published online: Jan 29, 2020
Published in print: Apr 1, 2020
Discussion open until: Jun 29, 2020
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.