Operational Modal Analysis of a Ship Model in the Presence of Harmonic Excitation  

作　　者：Junchen Xu Ming Hong Xiaobing Liu 

机构地区：[1]State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China

出　　处：《Journal of Marine Science and Application》2013年第1期38-44,共7页船舶与海洋工程学报（英文版）

基　　金：Supported by the National Natural Science Foundation of China（51079027）

摘　　要：A ship is operated under an extremely complex environment, and waves and winds are assumed to be the stochastic excitations. Moreover, the propeller, host and mechanical equipment can also induce the harmonic responses. In order to reduce structural vibration, it is important to obtain the modal parameters information of a ship. However, the traditional modal parameter identification methods are not suitable since the excitation information is difficult to obtain. Natural excitation technique-eigensystem realization algorithm （NExT-ERA） is an operational modal identification method which abstracts modal parameters only from the response signals, and it is based on the assumption that the input to the structure is pure white noise. Hence, it is necessary to study the influence of harmonic excitations while applying the NExT-ERA method to a ship structure. The results of this research paper indicate the practical experiences under ambient excitation, ship model experiments were successfully done in the modal parameters identification only when the harmonic frequencies were not too close to the modal frequencies.

关 键 词：natural excitation technique （NExT）  eigensystem realization algorithm （ERA）  ship structure  harmonic excitation  signal processing  modal parameters identification  ship model  operational model analysis 

分 类 号：O327[理学—一般力学与力学基础] U661.73[理学—力学]