两座高耸结构基于RSV-150激光测振仪的环境振动实测与模态识别

Ambient vibration tests and modal identification of environmental vibration of two high-rise structures based on RSV-150 laser sensing vibrometer

针对一座高23m的特种钢结构与一座高300m的钢筋混凝土电视塔,采用RSV-150超远工作距离激光测振仪,开展了结构在环境激励下的振动实测与模态参数识别。作为一种非接触式的测量方式,激光测振仪具有操作简单、测量便捷等优点。采用了基于随机子空间方法的结构模态识别算法,对实测到的结构速度响应进行了模态分析。分析结果表明,该算法具有精度高、稳定性好的优点,可以有效地获取结构的自振频率与阻尼。选择结构的不同部位作为激光测振的反射点,对实测的自振频率影响不大,结果离散性较小。进行了结构的简化有限元分析,数值模拟获得的模态信息与实测结果之间有较好的对应性,验证了试验方法的可靠性。

For a 23 m high special steel structure and a 300 m high reinforced concrete TV tower,the RSV-150 sensing vibrometer with ultra-long working distance was used to carry out the ambient vibration tests and modal identification.As a non-contact measurement technique,the laser sensing vibrometer has the advantages of simple operation and convenient measurement.The stochastic subspace identification method was adopted for modal analysis of the measured velocity responses.The experimental results show that the algorithm has the advantages of high precision and good stability,which can effectively extract the natural frequencies and damping ratios of the structure.Especially,selecting different parts of the structure as the reflection points has little effect on the measured natural frequencies,and variations of the experimental result are relatively small.Finite element analysis of the structures was carried out based on simplified models.The numerical modal results have a good correspondence with the measured ones,which verifies the reliability of the experimental technique.