Verification of the effectiveness of TMDs using wind tunnel section model tests

Wind tunnel tests for the Hoga Kusten Bridge, now under construction in Sweden, have suggested that the bridge will experience large torsional motions for the particular case of snow accumulated in the railings. The designers of the bridge proposed the use of tuned mass dampers (TMDs) to reduce these motions, thus ensuring the safety of the bridge for wind speeds above approximately 40 m/s. The effectiveness of the TMDs was tested in a wind tunnel at the Danish Maritime Institute (DMI) through section model tests, with the aim of optimizing the TMD design. Tests have shown the TMDs to be highly effective, reducing the RMS torsional motions of the deck by a factor of almost 10. Tests varying many parameters of the TMD design were conducted to optimize the TMD design; the greatest improvement in bridge deck performance was achieved by increasing the TMD mass moment of inertia ratio either by increasing the distance from the TMDs to the bridge centreline or by increasing the moving mass of the TMD.