Adaptive tuned mass damper with shape memory alloy for seismic application

Abstract

When the characteristics of the main structure are changed, tuned mass damper (TMD) is easy to meet off-tuning problem. The object of this study is to develop a TMD with shape memory alloy (SMA) to reduce the vibration caused by off-tuning under seismic excitations. By materials characterisation of SMA, when the working temperature rises from -40℃ to 65℃, the stiffness increases and the equivalent damping ratio drops. The SMA-based TMD was installed on a steel frame and tested under earthquake loading. The results show the SMA-based TMD is able to reduce the seismic response in the range of 34.09% to 47.77% at the tuned condition. However, by changing the main structural mass, the TMD was easy to be off-tuned. To retune the TMD, the SMA was heated and cooled for the TMD to resonate with the natural frequency of the main structure. When the SMA is cooled, the peak and RMS accelerations can be effectively reduced by up to 23.98% and 35.51%, respectively. It was found that the SMA-based TMD performs well if the frequency change of the main structure is in the same order. But when the temperature of SMA is increased higher than 19℃, the damping ratio of SMA decreases, which causes a less effectiveness in reducing the vibration. In the future, the combinations of multiple SMA bars in TMD should be studied, and the applications of SMAs with higher phase transformation temperature can be investigated to improve the sensitivity while heating.

Defect mitigation and structural control of cantilevered structures using shape memory wire based resonant stiffness sensing

“…Structural reinforcement is achieved by SMAs by adding stiffness to the structure in the form of connectors, braces, and so on 23 . SMAs are used extensively as an active vibration control element and can be used as tuned mass dampers, 24 used in structural engineering to rehabilitate and strengthen concrete structures by contracting and reducing the cracks as demonstrated in Song et al 15 The material possesses the highest actuation density that it produces high strain (8%), while the smart material PE produces only 1% strain. Since SMA offers more strain compared to PE, and PE is a sensor unlike SMA being a self‐sensor if designed appropriately; the recent trend is to use a hybrid approach, with piezo material as sensor and SMA as actuator 16,25 .…”

Use of 4D-printing and shape memory alloys to fabricate customized metal jewels with functional properties

“…NiTi is the most industrially exploited shape memory alloy because of its high mechanical stability, high strain recovery, high damping property, biocompatibility and corrosion resistance thus finding numerous engineering applications. The main uses of NiTi are medicine (such as stents, grafts, orthopedic staples, orthodontic archwires, eyeglass frames, sutures; Petrini and Migliavacca, 2011;Wen et al, 2018;Nespoli et al, 2015), aerospace and military (such as couplers in F14 planes, morphing, low-shock release and deployment; Hartl and Lagoudas, 2007;Simiriotis et al, 2021), safety (like damper and sprinklers; Huang et al, 2020;Zhang et al, 2020;Fang et al, 2020;Huang et al, 2020) and robotics (such as actuators; Copaci et al, 2020;Nespoli et al, 2010aNespoli et al, , 2010bNespoli et al, , 2012Nespoli et al, , 2014Borlandelli et al, 2015).…”

Effects of geometrical nonlinearity on the performance of bidirectional tuned mass dampers

“…In the area of civil engineering, TMDs are used to suppress the dynamic response of structures under time‐dependent loads such as wind and earthquake. TMDs have been widely used for vibration control, and many studies were done in this field 2–5,20–28 . TMDs can exhibit nonlinear behavior.…”

“…TMDs have been widely used for vibration control, and many studies were done in this field. [2][3][4][5][20][21][22][23][24][25][26][27][28] TMDs can exhibit nonlinear behavior. This type of behavior can occur due to the large displacement or geometrical configuration of the device.…”