基于BOTDA的钢结构全尺度应变监测方法及其试验研究

大型钢结构因为超载或者腐蚀等问题引起的结构失效越来越多，对大型钢结构进行全尺度监测是评估结构的剩余使用寿命和做出维修决策的关键。分布式光纤传感技术具备分布式、抗电磁干扰能力强等优点，适用于钢结构的全尺度监测。设计了传感光纤的全面和局部布设方法，对上述方法进行了标定、重复性等试验，并将其应用于钢桁架的全尺度应变监测中。结果表明，分布式光纤传感技术可有效获取钢结构全尺度应变，同时，提出的基于电磁铁方式具备快速、可拆卸等优点。本文研究成果可用以集成大型钢结构健康监测系统，实现钢结构的全寿命健康状态评估。

Experimental research on full scale strain monitoring for steel structure based on BOTDA

Structure failures induced by overload or corrosion problems become the prevalent problem in large steel structures. Full scale monitoring in large steel structures is the key to evaluate the remaining service life of structures and make maintenance decisions. Distributed optical fiber sensing technology has advantages such as the applicability for distributed installation and the resistance to electromagnetic interference,which is suitable for monitoring the full scale of steel structures. This paper designed the entire and local layout method of optical fiber sensors. Calibration test and replicate test were carried out for this layout method,Meanwhile the full-scale strain monitoring was applied in steel truss structures. The results showed that distributed optical fiber sensing technology could acquire the full-scale strain of steel structures effectively. What’s more,this paper presumed a layout method based on electromagnet, which could be installed and disassembled conveniently. The research results could be applied in the health monito-ring system for integration of large steel structure,in order to evaluate the whole life health status of steel structures.