Accuracy of the half-power bandwidth method with a third-order correction for estimating damping in multi-DOF systems  

作　　者：Wang Jinting Lü Dandan Jin Feng Zhang Chuhan 

机构地区：[1]State Key Laboratory of Hydroscience and Engineering,Tsinghua University

出　　处：《Earthquake Engineering and Engineering Vibration》2013年第1期33-38,共6页地震工程与工程振动（英文刊）

基　　金：National Natural Science Foundation under Grant No. 51179093;National Basic Research Program of China under Grant No. 2011CB013602;Program for New Century Excellent Talents in University under Grant No.NCET-10-0531

摘　　要：A third-order correction was recently suggested to improve the accuracy of the half-power bandwidth method in estimating the damping of single DOF systems.This paper analyzes the accuracy of the half-power bandwidth method with the third-order correction in damping estimation for multi-DOF linear systems.Damping ratios in a two-DOF linear system are estimated using its displacement and acceleration frequency response curves,respectively.A wide range of important parameters that characterize the shape of these response curves are taken into account.Results show that the third-order correction may greatly improve the accuracy of the half-power bandwidth method in estimating damping in a two-DOF system.In spite of this,the half-power bandwidth method may significantly overestimate the damping ratios of two-DOF systems in some cases.A third-order correction was recently suggested to improve the accuracy of the half-power bandwidth method in estimating the damping of single DOF systems.This paper analyzes the accuracy of the half-power bandwidth method with the third-order correction in damping estimation for multi-DOF linear systems.Damping ratios in a two-DOF linear system are estimated using its displacement and acceleration frequency response curves,respectively.A wide range of important parameters that characterize the shape of these response curves are taken into account.Results show that the third-order correction may greatly improve the accuracy of the half-power bandwidth method in estimating damping in a two-DOF system.In spite of this,the half-power bandwidth method may significantly overestimate the damping ratios of two-DOF systems in some cases.

关 键 词：half-power bandwidth method third-order correction damping ratio estimation error two-DOF system 

分 类 号：TB532[理学—物理]