模拟环境激励下结构模态参数识别试验研究  

Experimental study of modal parameter identification in a simulated ambient-excited structure

作　　者：纪晓东[1] 钱稼茹[1] 徐龙河[1] 

机构地区：[1]清华大学土木工程系结构工程与振动教育部重点实验室,北京100084

出　　处：《清华大学学报（自然科学版）》2006年第6期769-772,共4页Journal of Tsinghua University(Science and Technology)

基　　金：北京市自然科学基金重点资助项目(8041002);国家自然科学基金重大国际(地区)合作研究项目(50420120133)

摘　　要：为了实现结构基于振动特性的健康监测,进行了在线模态参数识别。综合自然激励技术和特征系统实现算法,进行了模拟环境激励下结构的时域模态参数识别。利用特征灵敏度分析得到质量归一化振型。对一个两层钢支撑框架模型进行了模拟环境激励试验和力锤激励试验;通过改变结构质量和特征灵敏度分析,得到质量归一化振型;同时进行了有限元计算分析。通过试验模态参数识别与有限元计算得到的模态参数的对比,证明了该方法的有效性。Structure modal parameter online identification was used to monitor the structural health as evidenced by changes in the vibration characteristics. The natural excitation technique （NEXT） and the eigensystem realization algorithm （ERA） were combined to identify the modal parameters in the time domain in a structure excited by simulated ambient vibrations. The mass-normalized mode shapes were obtained from the eigen-sensitivity analysis. The experimental modal analysis was performed on a two-story steel braced frame model excitated by simulated ambient vibrations and hammer impacts. The mass-normalized mode shapes were acquired by changing the structural mass and eigen-sensitivity analysis. Finite element analysis results and the experiment data show that this method is effective.

关 键 词：结构振动 模态参数识别 自然激励技术 特征系统实现算法 特征灵敏度分析 

分 类 号：O327[理学—一般力学与力学基础]