Experimental Investigation of Load Sharing in Insulating Glass Units

Abstract

The method for determining load resistance of insulating glass in ASTM standards uses a load-share factor equation based only on glass-lite thicknesses to estimate the load carried by each lite. This paper presents an experimental investigation of load sharing of double- and triple-glazed insulating glass units. The major factors varied in the investigation include unit rectangular dimensions, glass-lite thicknesses, and initial airspace volumes. Pressure versus deflection curves are presented for select insulating glass unit configurations. A second testing procedure explores the measured change in pressure within the sealed airspaces while simultaneously measuring applied pressure and associated deflections. Changes in pressures in the sealed airspaces are directly compared to the ASTM standard load-share factors. Figures in this paper show the load-sharing trends of various similarly loaded insulating glass units, and the results presented in this paper suggest many of the neglected factors significantly influence load sharing in insulating glass units.