A TUNED MASS DAMPER DESIGN BASED ON EDDY CURRENT DAMPING

A tuned mass damper (TMD) based on the eddy current damping (ECD) mechanism is studied for space applications. Passive controlled TMD’s are simple devices because they do not have any means of an active control element. They are tuned to their operating natural frequency and their damping characteristics are pre-determined before their operational use. Moreover, they do not require any external power source to operate, they are highly reliable and require minimal maintenance. In this work, an ECD based TMD is created by placing a permanent magnet inside of a conductive tube. The damping is realized by electromagnetic forces in a non-contact and non-fluidic manner which eliminates any sealing or packaging problems. The design of the TMD is accomplished utilizing the copper material as a superior electrically conductive tube and titanium is used for the support structures as it has low magnetic properties and low electrical conductivity. Damping realized from ECD is maximized by placing a NdFeB N35 magnet inside of a copper tube and design of the TMD is optimized to achieve the maximum ECD possible. The ECD based TMD is tested by two dedicated experimental setups. One of them is used to measure the damping coefficient of the TMD. In the second experimental setup, the TMD is used to control the damping of a simple fixed-free beam. It is shown that the experimental results are found to be consistent with respect to the theoretical results. Moreover, the usage of the TMD reduced the accelerance levels up to 50% at the fundamental natural frequency of the main structure.