Cold Bent Laminated Glass Application – Numerical Research

In curvilinear and free‐form glass facade constructions, more and more cold bent laminated glass is applied. The high optical quality of cold bent glass allows for continuously smooth curved and high transparent facades. Moreover, a high performance and economical design is achieved using spatial load‐bearing behaviour. The bending in such curved glass facades is obtained by mechanical fixings upon a curved substructure at the installation on site or by lamination bending with stiff interlayers. These techniques shape the glazing but induce permanent bending stresses as well as shear stresses in the laminated glass, which significantly depend on the interlayer's material behaviour as a function of time and temperature. For the application of cold bent laminated glass in facades numerous factors must be considered ‐ achievable bending radii, glazing dimensions and geometry, load‐bearing capacities, bending forces as well as required supports. These aspects are significantly influenced by the material stiffness of the interlayer type and the glass structure. For this reason, the curved bending process with mechanical line fixings was numerically investigated. The focus lays on the influence of the stiffness of the polymer interlayer and the corresponding suitability for uniaxial cold bent laminated glass applications in different geometries. In the present paper, technical design information is introduced based on numerical simulations to assist designers in understanding the principles of uniaxial cold bent laminated glass with different glazing parameters. In conclusion, constructive recommendations for application in curvilinear glass facades are given.