Coupled tuned mass dampers for control of coupled vibrations in asymmetric buildings

An arrangement of tuned mass dampers, termed coupled tuned mass dampers (CTMDs) has been introduced, where a mass is connected by translational springs and viscous dampers in an eccentric manner. The CTMD has coupled modes of lateral and rotational vibration, which have been utilized to control coupled lateral and torsional vibrations of asymmetric buildings. An efficient control strategy has been presented in this context to control displacements as well as acceleration responses of asymmetric buildings having asymmetry in both plan and elevation. The building is idealized as a simplified three-dimensional model with two translational and a rotational degrees of freedom for each floor. The principles of rigid body transformation have been incorporated to account for eccentricity between center of mass and center of rigidity. A nondominated sorting genetic algorithm (GA) has been used for solving the multi-objective optimization problem. Tuning of optimum locations of TMDs and their parameters have been done from the multiple pareto-optimal solutions obtained simultaneously. Comparative studies of performance of CTMD with conventional TMDs and bi-directional TMDs have been presented. It has been observed that CTMDs are more effective and robust in controlling coupled lateral and torsional vibrations of asymmetric buildings. The optimal locations have been observed to be reasonably compact and practically implementable for CTMDs. Copyright (c) 2005 John Wiley & Sons, Ltd.