模态参数识别新算法提纯算法研究

详细信息    查看官网全文

• 英文论文题名：New Modal Parameter Identification Algorithm–Purifying Algorithm Study
• 论文作者：刘进明 ; 刘峰 ; 朱伟东
• 英文论文作者：Liu Jinming ; Liu Feng ; Zhu Weidong ; China Orient Institute of Noise & Vibration ; Beijing Institute of Technology ; University of Maryland
• 年：2016
• 作者机构：北京东方振动和噪声技术研究所;北京理工大学;University of Maryland;
• 论文关键词：参数识别 ; 频响函数 ; 纯模态试验 ; 解耦 ; 模态指示函数
• 英文论文关键词：Modal Parameter Identification ; FRF ; Pure Normal Mode Test ; Decomposition ; MvMIF
• 会议召开时间：2016-08-12
• 会议录名称：第十六届全国模态分析与试验学术会议论文集
• 语种：中文
• 分类号：V216
• 学会代码：ZGZH
• 会议名称：第十六届全国模态分析与试验学术会议
• 会议地点：中国天津
• 主办单位：中国振动工程学会模态分析与试验专业委员会
• 学会名称：中国振动工程学会
• 页数：17
• 文件大小：829k
• 原文格式：D
• 会议级别：全国

摘要

模态试验的频响函数有共同的分母,决定了模态的频率和阻尼。频响函数由多个模态叠加而成。本文提出的提纯算法,即为每个频响函数找出合适的权系数,多个频响函数计权相加后可以得到只含一阶模态的新频响函数。SIMO和MISO提纯后可得到一个频响函数,按单自由度识别模态频率和阻尼。MIMO提纯后多组频响函数可合成得到一组只含一阶模态的频响函数,按单自由度识别模态频率,阻尼和振型。新算法将传统的密集模态解偶转化到了简单的频响函数提纯,参数识别过程也不需要稳定图,计算速度有极大的提高。当多变量模态指示函数或复模态指示函数存在时,参数识别的速度可达到实时级。MIMO试验只要参考点数量合适,即使能量占比很小的模态,通过提纯算法也可得到非常协调的模态振型,精确的模态频率和阻尼。新算法尤其适用于耦合严重的超大阻尼模态试验。频响函数的提纯过程和飞机地面试验GVT的纯模态试验非常类似。
There is common denominator for the FRFs of mode test which is determined by the modal frequencies and damping ratios. The FRF is the superposition of multi modes. The purifying new algorithm put forward here is searching for the suitable weighting coefficient for each FRF to construct the new FRF,which is the weighting sum of multi FRFs,only includes one mode. For SIMO and MISO test,one purifying FRF can be obtained,the modal frequency and damping ratio can be identified according single freedom theory. For MIMO test,one group of purifying FRFs can be obtained. The new algorithm translates the complex close modes decomposition process to simple FRF purifying,and getting rid of the stable graph in the process of parameters identification,the computation speed is accelerated greatly. When the MMIF or CMIF curves are exist,the speed of parameter identification can reach real time. If the number and position of reference points are suitable in MIMO test,even the mode with small energy can obtain the harmonious vibration shape,precise modal frequency and damping ratio. The new algorithm is especially suitable for structure of seriously coupled with great damping ration. The FRF purifying process is very similar to pure normal modal test,or the Ground Vibration Test of plane.

引文

[1]J.M.Liu,Q.H.Lu,H.Q.Ying,The Best Force Design of Pure Modal Test Based Upon a Singular Value Decomposition Approach,Advanced Aerospace Applications,Volume 1,Conference Proceedings of the Society for Experimental Mechanics Series,2011,Volume 4,119-129,DOI:10.1007/978-1-4419-9302-1_11
    [2]W.Heylen,S.Lammeans,P.Sas,Modal Analysis Theory and Testing,K.U.Leuven,1998
    [3]Robert E.Coleman,Ranall J.Allemang,Experimental Structural Dynamics,2004,Author House
    [4]J.M.Liu,S.W.Dong,M.Ying,S.Shen.Dynamic Parameters Identification Technology in Bridge Health Monitoring,Proceeding of the 14th ASIA PACIFIC VIBRATION CONFERENCE,2011,Dec.HongK ong
    [5]William R.the Multivariate Mode Indicator Function in Modal Analysis Proc,3th IMAC 1985
    [6]Nash M.Use of the Multivariate Mode Indicator Function for Normal Mode Determination.Proc,6th IMAC1988