A reduced-order modeling technique for tall buildings with active tuned mass damper

It is impractical to install sensors on every floor of a tall building to m easure the full state vector because of the large number of degrees of free dom. This makes it necessary to introduce reduced-order control. A kind of system reduction scheme (dynamic condensation method) is proposed in this p aper. This method is iterative and Guyan condensation is looked upon as an initial approximation of the iteration. Since the reduced-order system is u pdated repeatedly until a desired one is obtained, the accuracy of the redu ced-order system resulting from the proposed method is much higher than tha t obtained from the Guyan condensation method. Another advantage of the met hod is that the reduced-order system is defined in the subspace of the orig inal physical space, which makes the state vectors have physical meaning. A n eigenvalue shifting technique is applied to accelerate the convergence of iteration and to make the reduced system retain all the dynamic characteri stics of the full system within a given frequency range. Two schemes to est ablish the reduced-order system by using the proposed method are also prese nted and discussed in this paper. The results for a tall building with acti ve tuned mass damper show that the proposed method is efficient for the red uced-order modelling and the accuracy is very close to exact only after two iterations. Copyright (C) 2001 John Wiley & Sons, Ltd.