摘要
大型基础工程结构的特征参数识别通常是通过对环境载荷激励的结构响应进行分析来实现,随机减量(Random Decrement,RD)技术是环境激励下的模态参数识别方法中应用较广的方法。在实际应用中受环境、测量等条件的限制,信号常为含有某些优势频率的非平稳信号,常常导致随机减量技术在识别结构参数尤其是系统阻尼时带来较大误差。为提高随机减量技术在环境激励作用下识别结构参数的准确性,文中从分析随机减量信号频谱中的频率分布特性入手,结合随机减量函数产生的触发条件,给出了一种利用信号频谱的统计特征进行模态参数识别的方法。数值仿真结果表明该函数能准确识别在含有优势频率环境载荷作用下的结构参数。
Characteristic parameters identification of major en- gineering structures is often performed by analyzing the responses of structure to ambient load excitation, the random decrement （RD） technique is more widely applied method of modal parameters iden- tification under ambient excitation. As the restriction by conditionsas environment, measurement and etc. in actual application, the signal usually is non-stable signal containing some dominant fre- quencies, this causes the random decrement technique to bring much bigger deviation in identifying structure parameters, particular in system damping. In order to improve the accuracy of random decrement technique in identifying structure parameters under the action of ambient excitation, by starting from analyzing the frequen- cy distribution characteristics in random decrement signal frequency spectrum, and introducing the trigger condition that generates therandom decrement function, the paper gives a method that carries out modal parameter identification by using statistic characteristics of signal frequency spectrum. Numerical simulation demonstrates that the function can accurately identify structure parameters under the action of ambient load containing dominant frequency.
出处
《机械设计》
CSCD
北大核心
2012年第8期1-5,共5页
Journal of Machine Design
关键词
环境激励
随机减量技术
特征参数识别
大型工程结构
ambient excitation
random decrement technique
characteristic parameter identification
major engineering structure
