不同桥梁模型结构自振频率识别方式对比分析

Comparison and Analysis of Natural Frequency of Vibration of Bridge Model

数字图像相关法(DICM)是测定结构自振频率较新的方法,为检验其在桥梁自振频率测定中的可行性,设计了桥梁模型试验。结果表明接触式速度传感器在环境激励和人工激励两种条件下都可以获得结构的频谱曲线。(DICM)在人工激励下可以获得与之接近的结果,在环境激励下(DICM)容易受到环境干扰而无法获得有效的频谱曲线,在利用数字图像相关法来测定结构自振频率时,应进一步研究在结构位移较小(如<0.005)时的干扰过滤技术。

Digital image correlation method（DICM）is a new way to determine the natural frequency of structures. In order to test availability of this method in bridge model natural frequency,the experiment of bridge model was de-signed. The results showed that using the speed sensor,the frequency domain curves both under artificial excitation and under displacement were valid. As the contrast,the results using DICM were valid only under artificial excitation and were close to results that of using speed sensor. When under the displacement,the frequency domain curve was not valid because of the stochastic disturbing. So when using DICM to determine the natural frequency of structure, intensive study of filtrating,such as the displacement is less than 0.005,the stochastic disturbing should be done.