Design And Numerical Study Of An Innovative Damper Based On Shape Memory Alloy

The shape memory alloys (SMAs) have been developed as the innovative intelligent material and has a good application prospect in structural vibration control because of its shape memory effect (SME) and superelasticity (SE). Numerous studies have been conducted in using SMA for structural vibration control, and some development have been attained. However, there still exist some problems in design and application of SMA damper, there has not yet engineering application by far. So design and study on an innovative SMA damper are carried out through theory analysis, experiment study and computer simulation.(1) Experiments on the mechanical behaviors of the superelastic NiTi wires are performed. Cyclic number, strain amplitude and strain rate are considered as test parameters to investigate their effects on the mechanical parameters such as phase transformation stress, energy dissipation per cycle, secant stiffness, equivalent damping ratio and residual strain. The experimental results show that the superior characteristics of superelastic NiTi wires, such as high energy dissipation, large restoring deformation, are suitable for passive vibration control devices in civil engineering.(2) Based on the experimental results, the Brinson's one dimensional constitutive model is employed to reflect the dynamic hysteretic behaviors or the cyclic mechanical behaviors of SMA. The corresponding computer programs are programmed and the simulated results are compared with the text results. The simulated results and the text results are almost identical with each other.(3) An innovative recentering damper device is designed, which provides perfect energy dissipation compatible with a negligible residual displacement, and has such advantages as simple configuration. The corresponding computer programs are programmed to simulate the mechanical behavior of the damper under static reversed loading. The simulated results show a double-flag shape force-displacement hysteretic curve of the SMA damper.(4) Dynamic time history analysis of a one-story steel structure and a three-story steel structure incorporated with the SMA damper was carried out. The analysis results indicate that the SMA damper can suppress structural displacement response effectively and can suppress structural acceleration response to a certain extent.