Application of Semi-active TMD to Tilted High-Rise Building Structure Subjected to Seismic Loads

Landmark structures are commonly constructed as tall buildings with complex shapes, such as twisted, tilted, and tapered towers. Although the appearances of these buildings are attractive, their structural safety must be investigated more carefully in comparison with conventional high-rise buildings. Especially in the case of a tilted high-rise building, lateral displacement even occurs from its own weight. Therefore, seismic response reduction is a very important issue for a tilted-form tower to secure structural safety. In this study, a semi-active tuned mass damper (SATMD) was employed for a tilted high-rise building subjected to seismic excitations, and its dynamic-response reduction capacity was evaluated. Two 300-kN magnetorheological (MR) dampers were employed to make a SATMD, which was installed on the top of a 100-story tilted example building. A fuzzy inference system controller (FISC) was used to make appropriate command voltages to control the SATMD. The various design parameters of the FISC were optimized by an evolutionary multiobjective optimization technique. A conventional semi-active groundhook controller was also used for comparison. The control performance of the proposed SATMD was compared to that of a conventional optimal passive TMD. The numerical results show that the fuzzy-controlled SATMD provided the best control performance. The proposed SATMD provided similar control performance while using only less than 30% of the mass quantity compared to passive TMD.