Generalized pseudo-excitation method and its application for vibration control of wind/seismic resistant buildings.

摘要

This dissertation presents a generalized pseudo-excitation method for random vibration analysis of buildings with supplemental discrete control devices and its application to various types of vibration control problems of wind/seismic resistant buildings.; The generalized pseudo-excitation method is actually a combination of the complex modal superposition method and the pseudo-excitation method. The proposed method can naturally retain all cross-correlation terms between closely spaced modes of vibration in structural response and accurately handle the nonorthogonal structural damping due to the installation of discrete control devices. The method also provides a convenient way of determining internal force response of a building. The principle and algorithm of the generalized pseudo-excitation method is first applied to a wind-excited tall building with active tendon devices and a wind-excited tall building with a light appendage at its top. The numerical examples show that for the tall building with a light appendage under alongwind excitation, the classical random-vibration-based modal superposition method (the SRSS method) may underestimate or overestimate the building response. The installation of active tendon devices may alter the natural frequencies and increase the modal damping ratio of the building so significantly that the building is no longer lightly damped or possesses the orthogonal damping property.; To pursue the application of modern control algorithm and the closed form solution for wind-excited tall buildings with active control devices, the cross-spectral density matrix of alongwind excitation on a tall building is factorized. The generalized pseudo-excitation method is then applied to find the closed form solution for wind-induced response of the building implemented by active control devices with Linear Quadratic Gaussian (LQG) controllers. The effectiveness of active control devices with LQG controllers in reducing wind-induced vibration of tall buildings is investigated. The advantages and disadvantages of this approach are discussed in the dissertation.; The generalized pseudo-excitation method is then extended to investigate modal properties and seismic response of steel frames with connection dampers. The connection dampers are modeled as rotational springs and rotational dampers in parallel. The dissertation derives the mass, stiffness, and damping matrices for the beam element with connection dampers using a combination of the finite element method and the direct stiffness method. (Abstract shortened by UMI.)