自由梁的位移、应变和声模态分析  

Analysis on Displacement,Strain and Acoustic Modal of Free-Free Beams

作　　者：李存鹏[1] 魏少东[2] LI Oun-peng1, WEI Shao-dong2(1. Anhui National De{ence Vocational College, Liuan, Anhui 237011 China; 2. China Orient Institute of Noise＆Vibration, Beijing, 100085, China)

机构地区：[1]安徽国防科技职业学院,安徽六安237011 [2]北京东方振动和噪声技术研究所,北京100085

出　　处：《河北北方学院学报（自然科学版）》2018年第7期38-41,共4页Journal of Hebei North University:Natural Science Edition

基　　金：安徽省高校自然科学重点研究项目(KJ2017A779)

摘　　要：目的针对目前常见的模态测试方法开展试验模态分析,从而给出各种测试方法的最优使用场所。方法以金属自由梁为研究对象,通过试验模态分析,得到了其位移、应变和声模态的频率、阻尼比和振型等模态参数,对比各模态测试方法的结果,并就各模态测试方法的特点开展对比分析。结果位移模态所测模态频率明显比应变模态和声模态的小,可见传感器的质量对所测自由梁位移模态的模态频率有较大影响,应变模态影响较小,声模态为非接触式测量,故无影响,且在相同的试验条件下,更容易得到高阶模态。结论应变模态试验在获取模态振型的基础上,也可进行各测试点应变大小的测量和计算。Objective To carry out experimental modal analysis for the current modal testing methods so as to give the optimal location of various testing methods.Methods By using metal free beam as the research object,through experimental modal analysis,modal displacement,strain and modal frequency,damping ratio and modal parameters were obtained,The modal testing results were compared and a comparative analysis of characteristics of the modal test method were carried out.Results The modal frequency measured by displacement modal was significantly smaller than that of strain modal and acoustic mode.The quality of the sensors has great influence on the modal frequency of measured free beam displacement mode.The sensor had a little influence on the strain mode,while the acoustic mode was non-contact measurement,so there was no effect on it,and in the same experimental conditions,it was more easily to get high order mode.Conclusion The strain modal test can be used to measure and calculate the strain of each test point on the basis of obtaining the modal shape.

关 键 词：自由梁 位移模态 应变模态 声模态 

分 类 号：TB124[理学—工程力学]