An Investigation Of A New Type Of Shape Memory Alloy Damper And Its Application For Roofs Of Stadium

This thesis presents a design and study of a new type of Shape Memory Alloy (SMA) damper and its application for vibration control of roofs of stadiums. First, the state-of-the-art researches of vibration control technologies on long-span spatial structures and the overview of SMA applications in structural vibration control are summarized. Then, performance tests are made on a kind of austenitic superelastic NiTi shape memory alloy wire. The energy dissipation capability of the wire and the influence of strain amplitude, loading frequency, as well as number of cycles, on working performance of the SMA wire are investigated. Based on the test, a new type of SMA damper is designed and its theoretical model is set up. Then, a detailed experimental investigation is carried out in order to get a full understanding of working performance of the damper, from which the effects of strain level, temperature, as well as frequency and pre-strain of SMA wires are taken into account. The theoretical model is verified by the experiments. Based on the design of passive SMA damper, a concept design on smart SMA dampers (both active and semi-active) is further put forward by utilizing the shape memory effect of martensite SMA wires. Finally, Vibration control theory and methods are studied by applying SMA dampers to roofs of stadiums, and the control effectiveness are analyzed. It is shown that the new type of SMA damper developed in this thesis is very effective to mitigate earthquake responses of structures.