Innovative steel glass composite structures for high-performance building skins (S+G) : final report

Theoretical and experimental investigations have confirmed that ferritic stainless steel, due to its unique properties in terms of thermal expansion, is the best commercial metal to be bonded with glass, to form high-performance unitized cells. The testing activity on reduced-scale specimens has allowed to assess the properties of the steel-to-glass bonding with different-in-type adhesives, including the innovative TSSA. Technological issues related to its application in long strips have been addressed. The possibility of obtaining a strong steel-to-glass bonding has led to the design of three different unitized cells, amenable of cold-twisting to obtain curved surfaces, applicable to different kinds of buildings and architectural contests. Twelve full-scale prototypes, with different adhesive materials and geometries, have been produced and tested until failure, to determine their load-bearing capacity under out-of-plane (pressure and suction) and in-plane loading. The energy efficiency of the cells has been assessed through experimental and numerical investigations. The analytical, numerical and experimental activities on cold-twisted panels have highlighted a previously almost unknown buckling phenomenon, of great interest for practical applications to curved building envelopes. In general, the structural response of the cells has been found to be excellent, due to the synergetic action between the curved glass panel and the contouring steel frame. Several scientific articles, published in international journals and conference proceedings, record the major obtained results. Technical Research Documents and Guidelines have been written, and a Final Workshop has been organized, to disseminate the new concept among designers and building industries working in the field of steel-glass structures.