Experimental study on performance of Ti-Ni shape memory alloy composite suspension damping system

Abstract

In this paper, the varying laws of stress–strain curve, feature point stress, energy dissipation capacity, and equivalent damping ratio of shape memory alloy wires were studied with the variation of diameter of wires, strain amplitude and cyclic loading times. The results show that the mechanical properties of SMA wire tend to deteriorate with the increase of wire diameter. When the strain amplitude reached 6% and the loading cycles reached 15, SMA wire could be formed with good hysteretic performance and working stability. Based on the superelastic property of the trained SMA wire and the basic working principle of tuned mass damper (TMD), a kind of detachable SMA suspension pendulum damping system convenient for disassembly was designed and fabricated. For this kind of damping system, the corresponding performance tests were completed, and the natural frequency of the system, the phase relationship between the mass vibrator and the controlled structure, and the variation of the equivalent damping force with the mass of the vibrator and the length of the pendulum rod were analyzed. The results show that the phase relationship between the mass vibrator and the controlled structure maintains between 150°∼180° under sine wave and real earthquake excitation, meanwhile the control effect increases with the rise of equivalent damping force. Above all, the system can be easily applied to the control of structural vibration, and provide stable and efficient damping force, so that the structure can be protected from strong dynamic disasters.