| Title |
Free Vibration of Torsionally-coupled Buildings with Tuned Mass Dampers |
| Abstract |
Tuned mass dampers are usually installed in the buildings with same axes of mass and stiffness of their structural plans to reduce the vibration under earthquake or wind excitation. However, if their structural plans do not have two axes of mass and stiffness symmetry, buildings subjected to earthquake undergo lateral as well as torsional motions. In this case, the effectiveness of tuned mass dampers in reducing coupled lateral-torsional vibration of buildings has not been studied widely.To understand the effect of tuned mass dampers on the coupled lateral-torsional vibration of buildings, the relationship between modes is studied first. The Lagrange multiplier formulation is used to derive the characteristic equation in terms of modal properties of a building and tuned mass dampers. The equation is transformed to have non-dimensional parameters such as eccentricity ratio of building rigidity, Mass ratio of building and tuned mass damper, the uncoupled torsional to lateral frequency ratio, and location ratio of tuned mass damper. These parametric study clarifies the coupling of lateral-torsional modes and help understand the effect of tuned mass dampers on torsinally-coupled buildings. |