Optimal design of glass plates loaded transversally

This paper focuses on glass used in buildings and presents a criterion for fail-safe optimal design of glass plates. First, the paper shows that the glass plate is fail-safe only if the load-bearing system is composed of two glass layers bonded to one another with an elastomeric interlayer (Laminated Glass), and if the live loads act upon a sacrificial glass ply (tri-layer system). Then, activity was directed at analyzing the simply-supported fail-safe glass plate loaded out-of-plane, and carrying out research targeted at reducing the incidence of weight and cost (optimal design). The results, obtained using an analytical exact model, show that the limit states are always dictated by the maximum deflection and not by the load-carrying capacity. Thus, optimal design requires finding the thickness of the glass layers and the stiffness of the interlayer that provide the plate with exactly the minimum allowable stiffness, while the stress verifications are fulfilled automatically. Finally, for every span and load that is found in building applications of glass, the paper provides the thicknesses and the materials of the glass layers and interlayers that adjust capacity to match demand. These results may also replace structural analysis and assessment of Laminated Glass plates.