Assessment of Stresses in Float and Tempered Glass Using Eigenstrains

Residual stress data determined using the contour method has been used to determine the misfit-strains (i.e., eigenstrains) existent in float glass. Although the uncertainty associated with the results of the contour method analysis may be high the results agree with the residual stress profiles measured using scattered-light-polariscope experiments. The relationship between the eigenstrains and the thickness of glass has been investigated and the results have been validated using scattered-light-polariscopic experiments. The paper shows that the eigenstrain distribution depends on the differential cooling takes place during the manufacturing process. Once the underlying eigenstrain distribution in a given float glass product has been determined this can be used to devise the eigenstrain distribution in tempered glass. It is also shown that eigenstrain analysis can be implemented in finite element models to predict structural response of glass structures thereby to ensure efficient, safe and reliable designs.