一种模态参数识别的虚假模态剔除技术  

A Technique of False Mode Elimination in Modal Parameter Identification

作　　者：王树青[1] 王典鹤[1] 林裕裕[1] 王巍巍[2] 李慧[2] 

机构地区：[1]中国海洋大学山东省海洋工程重点实验室,山东青岛266100 [2]海洋石油工程股份有限公司,天津300451

出　　处：《中国海洋大学学报（自然科学版）》2012年第9期97-101,共5页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(50909088;51010009);国家高技术研究发展计划项目(2008AA092701);教育部新世纪优秀人才支持计划项目(NCET-10-0762)资助

摘　　要：针对背景噪声下结构的模态参数识别结果存在虚假模态的情况,分析虚假模态产生的原因,通过理论推导提出辨别虚假模态的判断条件,根据判断条件剔除识别模态参数中包含的虚假模态。以比例阻尼海洋平台结构数值模型为例,在模拟噪声水平5%的工况下,获得结构脉冲响应信号,对基于奇异值分解定阶消噪后的信号用复指数法进行模态参数识别,对识别的模态频率和阻尼比进行虚假模态剔除。结果表明:根据判断条件可有效剔除所识别参数中的虚假模态。Under noisy background,structural modal parameter identification includes false modes.The causes of false mode in the identified modes were analyzed and two criteria of discriminating false modes from system modes were derived in this paper for eliminating the false modes.Numerical study was conducted of an offshore platform with Rayleigh damping system.First the structural impulse response signal was acquired and a level of 5% noise was added to the simulated signal.Then singular value decomposition was used for noise elimination and Least Square Complex Exponential method（LSCE） was taken to identify the modal parameters.Finally the two discrimination criteria were used for false modes elimination.The results show that the criteria are efficient in eliminating false modes.

关 键 词：模型定阶 信号消噪 复指数法 模态参数识别 虚假模态 

分 类 号：P752[天文地球—海洋科学]