Vacuum Insulated Glazing Under the Influence of a Thermal Load

The Vacuum Insulated Glazing (VIG) is a highly thermally insulating flat panel that is constructed from two glass panes, separated by an evacuated sub-millimetre gap, and hermetically sealed over its perimeter. Typically, solder glass is used as the edge seal, which results in a rigid bond between the glass panes over a 4-8 mm width. In-service the VIG unit not only withstands forces resulting from atmospheric pressure, but must also survive a temperature difference (thermal load) in extreme climates as large as 40°C. The glass pane on the hot side expands and on the cold side contracts, with the panes bonded rigidly, a mechanical force over the edge seal results in a bending moment. The aim of this paper is to present how the stresses resulting in the glass panes depend on the temperature difference over the VIG, the stiffness of the edge seal, and temperature field over the panes. Both analytic solutions and finite element modelling results are discussed.