Residual Stresses Near Holes In Tempered Glass Plates

This work presents numerical simulation results of the thermal tempering by the Finite Element Method in order to calculate transient and residual stresses near edges of a glass plate (2D calculation) and near holes (3D calculation). During thermal tempering, glass is considered as a viscoelastic material. The Narayanaswamy's model is used. It takes into account the structural relaxation phenomena. The particular difficulty is the correct modelling of heat transfers since transient and residual stresses strongly depend on the history of temperature within the plate, close to the edge and the hole. Both the forced convection due to the blowing of air and the radiative heat transfer are modelled numerically. The semi-transparency of glass in the near infrared range is considered. The convective heat transfer coefficients on the edge and hole walls are identified thanks to a specific experimental set-up and validated from simulations of heat transfer tests. The computed residual stresses are checked against photo-elastic measurements.

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The Authors

Mr. Laurent Daudeville Professor Laboratoire Sols, Solides, Structures Pr L. Daudeville is a specialist of numerical modelling of fracture and damage. His studies concerned the modelling of both the thermal tempering of flat glass (including stress relaxation and heat tr... Read more