A passive damping device with TiNi shape memory alloy rings and its properties

TiNi SMAs possess a high damping capacity both in the austenite and martensite state and can be used for energy absorbing and vibration damping applications. The main research object has turned to develop damping devices which contain SMAs members now. However, most SMAs damping elements in the energy dissipating devices are in the form of wires. A new kind of passive damping device that is composed of TiNi shape memory alloy rings was manufactured in this paper. The rings are made of TiNi strip with 1 mm thick and 25 mm wide. The inelastic properties of the device were investigated and its damping capacity analyzed. There still exist hysteresis loops during loading and unloading when the deformation of the rings is restricted properly, but the nominal stress–strain curves are titled and not parallel to the abscissa in the superelastic range. It may be of benefit to over loading that nominal stress–strain curves vary with the load and do not maintain in a constant value during the whole loading and unloading process. Otherwise, the damping properties of the device may be changed by adjusting the movable parts of the device to apply a pre-strain on the rings or by using different pieces or sizes of rings.