COMPARISON OF DIFFERENT SMA-BASED ADAPTIVE TUNED MASS DAMPERS

The use of smart materials has proven to be an effective strategy in the development of adaptive tuned mass dampers. Among different possible materials, shape memory alloys show specific features which make their use advantageous for building adaptive tuned mass dampers. More in detail, by heating/cooling the shape memory alloy components, it is possible to change the natural frequency of the adaptive tuned mass damper, thus allowing maintaining the adaptive mass damper tuned on the primary system to be damped. The heating/cooling is obtained by changing the amount of electrical current flowing through the shape memory alloy elements and, consequently, the amount of heat produced through Joule's effect. This paper compares the two main layouts for designing adaptive tuned mass dampers based on shape memory alloys in case the primary system to be damped is excited by a disturbance of random nature: cantilever beams and tensioned wires with a central mass. The two layouts, which can be described through detailed and experimentally validated models, are compared in terms of adaptation capability, exerted force and electrical power consumption. It results that the wire-based layout, despite being characterised by a more complicated set-up, is less demanding in terms of power consumption and shows much better adaptation capability.