Contribution to the Development of Cold Bent Glass Applications

Abstract

Traditionally, curved façade geometries can be achieved by the means of hot bending glass or tessellation of the underlying geometry into plane parts, or even combinations of aforementioned. While the first method is not cost, nor energy efficient, for it relies on a heating process and requires bending moulds for every geometry, the second requires a vast amount of opaque substructure, opposing the aim of translucent façade structures. Contrary to these methods, the cold bending of glass omits those detrimental side effects of modern façade design. So, a promising technique was developed by elastically applying the curvature at ambient temperature. Nevertheless, the widespread use is still opposed by surmounted imponderables, like advanced calculation models utilizing FEAs and missing experience in the application of this method.
This paper gives an extensive overview of the state of the art, like realized structures, deformation criteria and cold bending associated stress development, while also prompting a new analytical approach for the calculation of stresses in cold bent glasses. Moreover, a time-dependent buckling phenomenon on laminated glasses is discussed. In conclusion, aspects of the upcoming informative annex of the prEN 19100 (Eurocode 10 to be) on cold bending are discussed.