Buckling control using shape-memory alloy cables

This paper studies innovative restraining solutions based on lateral nickel-titanium (NiTi) shape-memory alloy (SMA) cables. Two novel control approaches are tested, which take advantage of superelasticity and the shape-memory effect. Superelasticity is employed in a passive control approach, using the restraining cables to increase the postbuckling resistance and recentering capabilities of a compressed column while dissipating energy. A numerical model to simulate this passive control system is also proposed and validated, adequately representing both its material and geometric nonlinearities. Additional parametric tests are performed, providing more insight into the good performance of the proposed system. The shape-memory effect (SME) is used in an active control approach, using the cables as actuators to counteract the buckling motion of the column. Experimental prototypes are built and tested in order to investigate the feasibility and effectiveness of these two control solutions, which aim to demonstrate the versatility of these exceptional materials for new structural applications.