L. Lani

Glass Tensegrity Trusses

High transparency and modularity, retarded first cracking, non-brittle collapse and fail-safe design were the basic requirements that inspired and guided the development of a new kind of glass beams. The two basic conceptual design goals were to avoid any cracking at service and to get a ductile behaviour at failure. These objectives were reached by a preliminary subdivision of the beam into many small triangular laminated panes and by assembling them together by means of prestressed steel cables. Two prototypes have been constructed at the University of Pisa, tested in the elastic domain under dynamics loads and successively brought to collapse under quasi-static, increasing load cycles. In order to investigate the decay process of residual mechanical resources, the second prototype has been repaired twice by substituting just the damaged triangular panes and then tested again each time up to failure. Experimental results resulted in a good agreement with non-linear numerical simulations performed by appropriate finite element modelling.