望远镜塔架系统试验模态分析  

Experimental Modal Analysis of Telescope Tower System

作　　者：杜福嘉[1,2] 李爱爱[1,2,3] 张志永 DU Fu-jia;LI Ai-ai;ZHANG Zhi-yong(National Astronomical Observatories/Nanjing Institute of Astronomical Optics ＆ Technology,Chinese Academy of Sciences,Jiangsu Nanjing 210042,China;Key Laboratory of Astronomical Optics ＆ Technology,Nanjing Institute of Astronomical Opt-ics ＆ Technology,Chinese Academy of Sciences,Jiangsu Nanjing 210042,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院国家天文台南京天文光学技术研究所,江苏南京210042 [2]中国科学院天文光学技术重点实验室,江苏南京210042 [3]中国科学院大学,北京100049

出　　处：《机械设计与制造》2018年第12期65-67,71,共4页Machinery Design & Manufacture

基　　金：国家自然科学基金资助项目(11373049;11190013)

摘　　要：塔架系统的振动特性对望远镜的成像质量具有重要的影响。以望远镜塔架模型为研究对象进行模态分析,针对无参数化模态分析引起模态参数不准确的问题,提出采用最小二乘复指数法(LSCE)进行试验模态分析,确定结构的模态频率、阻尼比和模态振型。通过稳态图方法剔除识别过程所衍生的虚假模态,又通过模态置信判据验证模态的相关性,提高了模态参数识别结果的准确性,与无参数化试验模态分析结果对比表明,模态频率的最大误差仅为4.4%,一致性较好,结果表明LSCE算法的正确性和适应性。The vibration characteristics of a telescope tower system have an important influence on image quality. The modal experiment of a telescope tower system is performed. In view of the problem of non parametric modal analysis, the least square complex exponential method （LSCE） is proposed to carry out experimental modal analysis. Modal frequency, damping ratio and mode shape of the structure are obtained. The stabilization diagram is built to reject the false modes and modal correlation is verified by modal assurance criterion. The calculated results are in good agreement with non-arametric modal analysis, and shows that the LSCE algorithm is correct and adaptable.

关 键 词：望远镜 模态分析 LSCE 稳态图 模态置信判据 

分 类 号：TH16[机械工程—机械制造及自动化] TH75