文章基本信息

标题：A Procedure to Identify the Modal and Physical Parameters of a Classically Damped System under Seismic Motions
本地全文：下载
作者：M. De Angelis ; M. Imbimbo
期刊名称：Advances in Acoustics and Vibration
印刷版ISSN：1687-6261
电子版ISSN：1687-627X
出版年度：2012
卷号：2012
DOI：10.1155/2012/975125
出版社：Hindawi Publishing Corporation
摘要：The purpose of this paper is to discuss a methodology for determining some modal parameters (frequencies, damping ratios, and seismic eigenvectors) and, under certain hypotheses, the physical matrices of a general structure with proportional damping and subjected to seismic loads. The procedure is based on a time-domain state space formulation from which the modal parameters, including the seismic eigenvectors, and the complex eigenvectors of the system can be derived also in the case of a limited set of instrumentations. The conditions to normalize the eigenvectors are then illustrated and, finally, applied to derive the second-order matrices of the system. The proposed procedure is applied to some numerical examples also in the case of noise-polluted measurements and to an experimental investigation performed on a four-story steel frame subjected to earthquake excitations. An optimization procedure to improve the prediction of the first-order modal parameters of the system is also discussed and experimentally proved.