Fiber-Optic Strain Sensor System With Temperature Compensation for Arch Bridge Condition Monitoring
Fiber-Optic Strain Sensor System With Temperature Compensation for Arch Bridge Condition Monitoring
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DOI：
10.1109/jsen.2011.2172991
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发表时间：
2012-05-01
影响因子：
4.3
通讯作者：
Grattan, K. T. V.
中科院分区：
文献类型：
--
作者：
Mokhtar, M. R.;Owens, K.;Grattan, K. T. V.
本文提出了一种创新的传感器系统，专为新的土木工程结构监测应用而创建，允许特殊封装的基于光纤光栅的传感器在恶劣的现场测量条件下使用，以实现具有完全温度补偿的精确应变测量。该传感器由两个光纤布拉格光栅组成，保护在聚丙烯包装内，其中一个光纤光栅不受应变的影响，因此只对温度变化做出反应，而另一个光纤光栅对应变和温度都很敏感。为了实现这一点，温度监测光纤光栅被略微弯曲并封装在金属外壳中，以有效地将其与应变隔离。因此，通过适当的校准过程，可以获得每个单独的光栅组件在合并到传感器系统中时的应变系数和温度系数。通过在传感器的工作中使用这些校准系数，可以准确地确定应变和温度。当这些传感器安装在创新的小规模柔性拱桥上时，可以看到这些传感器的具体应用，在关键安装阶段(吊装)和加载期间，这些传感器用于实时应变测量。这些传感器在嵌入或表面安装在这种混凝土结构上时表现出更强的弹性，不仅在安装过程中提供准确和一致的应变测量，而且在随后的使用过程中提供准确和一致的应变测量。这提供了一种廉价而高效的监测系统，专为各种土木工程应用的小规模桥梁安装的新的快速方法量身定做。
This paper presents an innovative sensor system, created specifically for new civil engineering structural monitoring applications, allowing specially packaged fiber grating-based sensors to be used in harsh, in-the-field measurement conditions for accurate strain measurement with full temperature compensation. The sensor consists of two fiber Bragg gratings that are protected within a polypropylene package, with one of the fiber gratings isolated from the influence of strain and thus responding only to temperature variations, while the other is sensitive to both strain and temperature. To achieve this, the temperature-monitoring fiber grating is slightly bent and enclosed in a metal envelope to isolate it effectively from the strain. Through an appropriate calibration process, both the strain and temperature coefficients of each individual grating component when incorporated in the sensor system can be thus obtained. By using these calibrated coefficients in the operation of the sensor, both strain and temperature can be accurately determined. The specific application for which these sensors have been designed is seen when installed on an innovative small-scale flexi-arch bridge where they are used for real-time strain measurements during the critical installation stage (lifting) and loading. These sensors have demonstrated enhanced resilience when embedded in or surface-mounted on such concrete structures, providing accurate and consistent strain measurements not only during installation but subsequently during use. This offers an inexpensive and highly effective monitoring system tailored for the new, rapid method of the installation of small-scale bridges for a variety of civil engineering applications.