摘要
基于高速摄影成像技术,利用改进的数字时间序列图像相关方法,测定了自由振动状态下拉索模型的模态参数。该方法具有实验装置简单、全场非接触、无附加质量、无附加阻尼、测量频率和位移范围可调等优点。采用高速CMOS摄像机及其计算机处理系统,实时获取拉索的振动图像,基于VC编制时间序列图像相关软件自动对序列图像进行相关运算,获得其位移-时程曲线;利用小波分析的方法确定拉索的固有频率和阻尼比,实验结果与理论分析结果吻合得较好。测试及分析结果表明:该方法为拉索模型的模态参数识别提供了新的途径。
High-speed cine photography technique and improved digital temporal serial image correlation method （IDTSICM） are employed to measure the modal parameters of the cable model under free vibration conditions. This technique has the advantages of being simple, whole-field, and non-contact. It also does not add additional weight and damping and can be adjusted to different ranges of frequencies and displacements. Images of the cable model are captured in real-time by high-speed CMOS camera. IDTSICM （programmed in VC＋＋ environment） is subsequently used to obtain displacement signal automatically. In this process, wavelet analysis is preferred to identify the modal parameters including frequency and damping ratio. Experimental results agree well with the theoretical values. Test and analytic results show clear evidence of the feasibility and advantages of IDTSICM and wavelet analysis in identifying the modal parameters of the cable modal, which confirms the new proposed method for investigation on vibration behavior of cable model at the engineering spot.
出处
《工程力学》
EI
CSCD
北大核心
2008年第6期88-93,共6页
Engineering Mechanics
基金
国家自然科学基金(10472026)
国家重点基础研究专项经费(2006CB300404)
关键词
光学测试
高速摄影成像
改进的数字时间序列图像相关方法
小波分析
拉索模型
模态参数
optical method
high-speed cine photography
improved digital temporal serial image correlation method （IDTSICM）
wavelet analysis
cable model
modal parameters
