Robust optimum design of tuned mass dampers for high-rise buildings subject to wind-induced vibration

<p style='text-indent:20px;'>Control devices are commonly applied to suppress structural displacement due to dynamic loads. In this work, a study of the optimum tuned mass dampers (TMDs) design was carried out, installed in a high-rise building subject to wind-induced vibration. Tuned mass dampers are the most known passive energy device and their design are an important area of study. A mathematical model to consider the wind force in the time domain was introduced. A procedure to obtain the robust design of tuned mass dampers was proposed through the optimization under uncertainties, which considers the uncertainties present in the structural properties of the building and also in the dynamic excitation. This method led to the robust design of TMDs, whereas the device performance became insensitive to the randomness of the input variables of the optimization problem. The robust design was compared with a design obtained by a deterministic optimization and the advantages of using an optimization under uncertainties are shown. In addition, the proposed methodology was compared with traditional TMD design methods, showing again the superiority of the proposed methodology.</p>

Prof. Comparing H2 and H∞ Algorithms for Optimum Design of Tuned Mass Dampers under Near-Fault and Far-Fault Earthquake Motions

In this study, the robust optimum design of Tuned Mass Damper (TMD) is established. The H2 and H∞ norm of roof displacement transfer function are implemented and compared as the objective functions under Near-Fault (NF) and Far-Fault (FF) earthquake motions. Additionally, the consequences of different characteristics of NF ground motions such as forward-directivity and fling-step are investigated on the behavior of a benchmark 10-story controlled structure. The Colliding Bodies Optimization (CBO) is employed as an optimization technique to calculate the optimum parameters of the TMDs. The resulting statistical assessment shows that the H∞ objective function is rather superior to H2 objective function for optimum design of TMDs under NF and FF earthquake excitations. Finally, the robustness of the designed TMDs is evaluated under a large set of natural ground motions.

Robust Optimum Design of Multiple Tuned Mass Dampers for Vibration Control in Buildings Subjected to Seismic Excitation

Passive energy devices are well known due to their performance for vibration control in buildings subjected to dynamic excitations. Tuned mass damper (TMD) is one of the oldest passive devices, and it has been very much used for vibration control in buildings around the world. However, the best parameters in terms of stiffness and damping and the best position of the TMD to be installed in the structure are an area that has been studied in recent years, seeking optimal designs of such device for attenuation of structural dynamic response. Thus, in this work, a new methodology for simultaneous optimization of parameters and positions of multiple tuned mass dampers (MTMDs) in buildings subjected to earthquakes is proposed. It is important to highlight that the proposed optimization methodology considers uncertainties present in the structural parameters, in the dynamic load, and also in the MTMD design with the aim of obtaining a robust design; that is, a MTMD design that is not sensitive to the variations of the parameters involved in the dynamic behavior of the structure. For illustration purposes, the proposed methodology is applied in a 10-story building, confirming its effectiveness. Thus, it is believed that the proposed methodology can be used as a promising tool for MTMD design.