Structural performance of linearly laminated metal fittings for frameless glass shell structures

Abstract Glass in facades and roofs is usually used as infill elements to provide daylight supply in buildings. The load is typically transferred via a substructure. This leads to resource-intensive constructions, whereby usually the static potential of the glass panes is not taken into account. In a research project, this missing efficiency was investigated, resulting in a linear metal edge fitting that enables load-bearing glass structures by transferring tensile and compressive forces as well as bending moments. The fittings are laminated into safety glass while the use of Insulated Glazing Units (IGU’s) provides thermal performance. Since insulating glass is typically not used as a primary load-bearing structure, the entire process chain had to be redesigned and developed, from 3D planning and form-finding to design and structural analysis, manufacturing, testing and assembly. The paper focuses on the structural performance of the developed fitting. Analytical models were used to approximate the rotational stiffness of the fitting, followed by parameter studies to understand the influence of key geometric and material variables. This revealed the importance of flange thickness on the overall rotational stiffness of the linear fitting. A full-scale mockup (approximately 7 m × 3 m) was assembled to assess buildability under real-world conditions, revealing both the practical viability and current limitations of the system. Mechanical testing on specimen with fitting dimensions used in the mockup led to a bending stiffness of 6 kNm. Among the identified challenges are the precision of the lamination process, control of welded seam quality, and long-term performance under environmental influences. Additionally, aspects related to thermal performance/building physics requirements and durability require further investigation before the system can be considered for broader application.