Control of torsional response in asymmetrical buildings subjected to seismic loading by using tuned mass dampers

DANIEL AMBROSINI; RICARDO BASSOTTI

San Diego, CA, USA

Congreso; 4th World Conference on Structural Control and Monitoring. 4WCSCM-001; 2006

In asymmetrical building in which the mass and shear centers are not coincident has coupled flexural and torsional responses, even when excited unidirectionally. In this case, the use of tuned mass dampers (TMD) in appropriated locations has a double beneficial effect: It is a mean for dissipation of seismic energy and it controls the torsional vibrations by applying a torsor moment out-of phase with the excitation. Then, the main objective of this paper is to study the efficiency of TMDs in the reduction of torsional response in asymmetrical buildings subjected to seismic loading. The physical model of the structure is based on a general formulation of beams based on the Vlasov's theory of thin-walled beams, which is modified to include the effects of shear flexibility and rotatory inertia, as well as variable cross-sectional properties. In addition, a linear viscoelastic constitutive law was incorporated. The load acting is constituted by a seismic loading introduced by a ground acceleration record. A numerical example is presented in order to obtain a preliminary quantification of the importance of the effect studied. Recommendations are made regarding the tuning frequency, the location of the TMDs and the optimum damping for torsional response.