Experimental Investigation of a Double Layer ‘Tensegrity’ Space Frame

This paper describes an experimental investigation into a half-scale structural model of a solar collector double layer tensegrity space grid that was originally proposed to cover the new National Opera House in Athens, Greece (see Figures 2-3). The structural scale model has a 5m span with cubic modules of 1.25m edge length. The key purpose of the experiment is to investigate the construction sequence, and, in particular, the pre-stressing of the structure. A novel pre-stressing scheme is used, where the top and bottom horizontal members are jacked apart, and a vertical compression member is lengthened. In practice, verification of pre-stressing is important, and a practical technique for measuring prestress in the diagonal members in the field through vibration measurements is described.