Design of point fitted insulating glass units

Today’s building façades are not imaginable without the building material glass. Modern architects capitalise the transparency and the load carrying capacity of glass elements in the design of filigree and light-flooded structures. Priority is thereby given to the maximal transparency and the energy efficiency of the glass façade. In fact, the strategy paper “EU 2020” formulated by the European Union has an important impact on the design of glass façade and the energy efficiency will be a focal point in the design of glass façades in future. The optimal combination of transparency and energy efficiency is achieved by using point fitted insulation glass units. Their application in glass façades becomes therefore indispensable in the future.
<br />Currently, three different point fitting systems for point fitted insulation glass units exist. They however present several disadvantages concerning their installation procedure and the tightness of the glazing cavity. Additionally, a general design concept for point fitted insulation glass does currently not exist. In consequence, point fitted insulation glass is a non-regulated construction product and requires an approval in individual cases from the national building authorities.
<br />A model to proof the structural integrity of a developed point fitted insulation glass unit with a suitable point fitting system and edge seal system is proposed. A state of the art investigation reveals the Fischer undercut anchor to be the most suitable type for the application in insulation glass. A novel design concept for point fitted insulation glass with undercut anchors is developed. The concept considers the determination of the climate loads and proposes a verification procedure for each structural element of the insulation glass unit. For this purpose, an existing climate load model for linearly supported insulation glass is analytically extended to the static system of point fitted insulation glass units with undercut anchors. For the verification of the connection undercut anchor in glass, an existing design method for point fitted single and laminated glazing is extended to point fitted insulation glass. Component tests are conducted on the Fischer anchor and its ultimate load bearing capacity in glass is determined. A calibrated numerical model of the proposed point fitted insulation glass unit with the Fischer anchor is developed for parametric studies. Large scale tests on the proposed new point fitted insulation glass unit are run with the aim to verify the numerical model, the climate load model and the extended design method and to proof the structural integrity of the entire unit. Finally a new point fitted insulation glass unit with a suitable point fitting type and a corresponding novel design concept is developed.