Seismic metamaterials with tensegrity architecture

The class of nonlinear metamaterials with tensegrity architecture is particularly interesting, since the mechanical behavior of such systems can be effectively adjusted by acting on internal and external prestress, as well as the usual controls of geometry, topology, and mechanical properties of the members. This work is focused on the development of 3D versions of the tensegrity braces (T-braces) recently proposed in the literature. The examined structures are aimed at forming novel seismic isolators, reinforcing seismic-resistant frames of steel and reinforced concrete buildings, as well as introducing the energy dissipation mechanisms of masonry walls, floor slabs, and junctions between seismic-resistant structures. This technology consists of lightweight and high-strength systems with re-centering capabilities formed by a variety of tensegrity systems. The tensegrity bracing systems incorporate superelastic shape memory bars/wires acting as pre-tensioned dissipative elements. The struts are prevented from buckling through the internal pretension of the braces via self-stress, and/or by contrasting them against the elements of the structure (external pre-tension). Using fractal geometry concepts, such systems can be designed through bio-inspired self-similar divisions of tensegrity brace modules to enhance both the energy dissipation capacity and the buckling resistance of the bracing system. Their development will significantly impact currently available techniques for the seismic protection of masonry and framed structures.