基于微波感知的挠性结构动态响应监测

Dynamic response monitoring of flexible structures based on microwave sensing

以大跨度桥梁、高架道路为代表的挠性结构在服役过程中的健康监测备受关注和重视,结构动态响应的测量是实现结构健康监测的重要途径。基于微波感知的新型非接触式振动测量(简称"微波测振")技术与方法,开展挠性结构动态特性监测的应用研究。阐述了微波测振系统的组成及基于单频连续波和调频连续波微波雷达的振动测量基本理论与方法。针对工程实际中挠性结构动态响应监测需求与特点,提出微波测振系统的工作模式选择与参数设置准则。基于搭建的微波测振系统开展了轻轨高架箱梁结构在列车运行激励下的振动响应监测实验研究,分析了不同工况下结构的动态响应特性。结果显示,微波测振技术与方法能够准确测量挠性结构的形变与动态响应,为军民领域挠性结构的健康监测提供了一种新的非接触式振动测量技术与方法。

The health monitoring of flexible structures, such as, long-span bridges and viaducts in their service has received much attention. The structural dynamic response measurement is an important way to realize structural health monitoring. Here, the dynamic response monitoring of flexible structures was investigated by using a new non-contact vibration measurement technology based on microwave sensing. Firstly, the composition of microwave vibration measurement systems, and the basic theory and method of vibration measurement based on single-frequency continuous wave(CW) and frequency-modulated continuous wave(FMCW) microwave radars were described. Then, aiming at requirements and features of flexible structures’ dynamic response monitoring in engineering practice, working mode selection and parametric setting criteria for microwave vibration measurement systems were proposed. Finally, based on the built microwave vibration measurement system, dynamic response monitoring tests for a light-rail elevated box girder structure under excitation of subway trains were conducted to analyze dynamic characteristics of the structure under different working conditions. Results indicated that the vibration measurement technology based on microwave sensing can effectively measure and monitor deformation and vibration response of flexible structures to provide a new non-contact vibration measurement technology and method for health monitoring of flexible structures.