  The present paper is concerned with deriving simplified design equations and
charts for modeling in-plane expansion of fractured thermally pre-stressed
glass panes using the method of equivalent temperature differences (ETD)
together with a thermal expansion analogy for strains. The starting point is a
theoretical method based on linear elastic fracture mechanics merged with
approaches from stochastic geometry to predict the 2D-macro-scale fragmentation
of glass. The approach is based on two influencing parameters of glass: (i)
fragment particle size and (ii) fracture particle intensity, which are related
to the pre-stress induced strain energy density before fracture. Further Finite
Element (FE) analysis of single cylindrical glass particles allow for
establishing functional relations of the glass fragment particle dimensions,
the pre-stress level and the resulting maximum in-plane deformation. Combining
the two parts of two-parameter fracture pattern modelling and FE results on
fragment expansion, formulas and engineering design charts for quantifying the
in-plane expansion of thermally pre-stressed glass panes due to fracturing via
an ETD approach is derived and provided within this paper. Two examples from
engineering practice serve as demonstrators on how to use our ETD approach to
compute the equivalent temperature difference and resulting internal forces as
well as deformations. This approach serves furthermore as a basis to estimate
secondary effects (such as fracture expansion-induced deformations or stresses)
on support structures or remaining parts of glass laminates in form of handy
ETD load cases within analytical as well as FE analysis.
