Study of Deflection in Insulating Glass Units Under Climatic Loads Simulation

Abstract

Insulating glass unit (IGU) is a commonly used filling element in transparent building partitions. The component glass panes in the unit are connected to each other on the edges by a spacer in such a way, that the space between them forms a tight gap filled with gas. The state of the gas in the gap can be described, with sufficient accuracy, by the law of ideal gases. Periodic changes in external climatic factors, above all atmospheric pressure and temperature, result in deflection of the component glass panes, which generates secondary loads associated with the change of gas pressure in the gap. The static quantities in the glass panes (deflection, stress) are therefore the result of the state of temporary equilibrium between the gas pressure in the gap and the external pressure. Measuring the deflection of component glass panes in operating conditions is time-consuming, because it requires waiting for changes in weather factors – these changes are often unpredictable. The aim of this article is to develop the concept of a test stand allowing the measurement of the deflection of the IGU models under the conditions of climatic loads changes simulation, where these changes can be controlled over time and generated in an orderly manner. The presented project meets these requirements. The stand is built from a massive main frame, which is the basis for the placement of deflection sensors, which is accompanied by a supporting frame, that allows placing glass panes with different thicknesses. The tested model of IGU is equipped with threaded elements, thanks to which it is possible to regulate the gas pressure inside the gap and monitor its temperature. An additional function of the stand is the ability to assess the tightness of the connection of component glass panes with the spacer, which may be an alternative to the standard way of testing this parameter.