Re-tuning an off-tuned tuned mass damper by adjusting temperature of shape memory alloy: Exposed to wind action

Abstract

To reduce the wind-induced vibration of building structures, tuned mass damper (TMD) is a widely used approach. However, the off-tune of TMD can cause larger excessive vibration to the structure. In this study, shape memory alloy (SMA) is employed in TMD for retuning. At first, the dynamic properties of SMA-based TMD were characterised by free vibration at between −40 °C and 65 °C. It is found the stiffness increased and damping reduced with rising temperature. Next, the SMA-based TMD was applied to a steel frame structure under wind excitations. The wind action was generated by autoregressive models method and input by a shaking table. The results present the wind-induced vibration can be attenuated effectively by installing a SMA-based TMD. By changing the main structural mass, the TMD was easy to be off-tuned and the structural response was increased. By means of cooling SMA to retune the TMD, the response of the system can be reduced effectively. However, the effect of heating SMA was relatively small. The increase of damping capacity by combing multiple SMA bars and the applications of SMAs with higher phase transformation temperatures are important to be further investigated in TMD, so as to improve the effectiveness of heating SMA.