stress distribution in thermally tempered glass panes near the edges, corners and holes : Part 1. Temperature distributions during the tempering process of glass panes

Abstract

While theoretical and experimental analyses of temper Stresses within the central areas of glass plates, i.e. for the theoretically "infinite plate", have been carried out in the past, the distributions of the induced Stresses near the edges and holes have yet to be examined in order to give a complete description of the stress field in the entire plate. The build-up of temper stresses depends on the temperature distribution as a function of time. For this reason, in part 1 of this paper the two- and three-dimensional cooling phenomena during the tempering process have been studied for all zones of a pane by means of analytical Solutions of the equation of heat conduction as well as by means of a discrete Simulation (Finite Element Method). The latter method allows for studying the temperature distributions in the vicinity of arbitrarily shaped holes. The influence of the tempering parameters (coefficient of heat transfer) and of the material constants on the temperature distribution is described, too. Part 2 of this paper deals with the induced distributions of temper stresses resulting from the thermal history of glass plates as defined in part 1.