Influence of curvature and geometrical parameters on internal pressure in cylindrical Insulating Glass Units

The application of curved glass provides exceptional freedom in the design of modern wavy shapes of building enclosures. The stiffness resulting from curvature has been identified as a remarkable advantage over flat glass, decreasing support requirements, and improving esthetics or increasing spans. However, many constraints arise regarding its design, manufacture, and performance during operation. Due to improved stiffness, curved Insulating Glass Units (IGUs) have a limited ability to equalize internal and atmospheric pressure changes by pillowing, compared to flat IGUs. High internal pressure values may lead to visible visual distortions or failure of the secondary seal. This paper presents the results of experiments, Finite Element (FE) and analytical simulations of flat and cylindrically curved insulating glass units. The study involved seven IGU specimens with 4 mm component panes and a 16 mm cavity. All specimens had a constant width (500 mm) but differed in length (500, 1000 and 1500 mm), and arc radius (two radii of curvature were used, 1500 and 2500 mm). In this study, the main focus was on the influence of geometric parameters on internal pressure in the cavity. The study uses a rarely used technique to simulate varying pressures in the IGU cavity by injecting or withdrawing of a defined volume of gas into/from the cavity.