基于分布式长周期光纤布拉格光栅传感器的单箱单室箱梁分布式变形监测。

Distributed Deformation Monitoring for a Single-Cell Box Girder Based on Distributed Long-Gage Fiber Bragg Grating Sensors.

机构信息

Department of Civil Engineering, Fuzhou University, Fuzhou 350108, China.

Hebei Province Key Laboratory of Evolution and Control of Mechanical Behavior in Traffic Engineering Structure, Shijiazhuang Tiedao University, Shijiazhuang 050043, China.

出版信息

Sensors (Basel). 2018 Aug 8;18(8):2597. doi: 10.3390/s18082597.

DOI:10.3390/s18082597

PMID:30096802

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6111534/

Abstract

Distributed deformation based on fiber Bragg grating sensors or other kinds of strain sensors can be used to monitor bridges during operation. However, most research on distributed deformation monitoring has focused on solid rectangular beams rather than box girders-a kind of typical hollow beam widely employed in actual bridges. The deformation of a single-cell box girder contains bending deflection and also two additional deformations respectively caused by shear lag and shearing action. This paper revises the improved conjugated beam method (ICBM) based on the long-gage fiber Bragg grating (LFBG) sensors to satisfy the requirements for monitoring the two additional deformations in a single-cell box girder. This paper also proposes a suitable LFBG sensor placement in a box girder to overcome the influence of strain fluctuation on the flange caused by the shear lag effect. Results from numerical simulations show that the theoretical monitoring errors of the revised ICBM are typically 0.3⁻1.5%, and the maximum error is 2.4%. A loading experiment for a single-cell box gilder monitored by LFBG sensors shows that most of the practical monitoring errors are 6⁻8% and the maximum error is 11%.

摘要

基于光纤布拉格光栅传感器或其他类型的应变传感器的分布式变形可用于在桥梁运行期间进行监测。然而，大多数分布式变形监测研究都集中在实体矩形梁上，而不是箱梁上——箱梁是实际桥梁中广泛使用的一种典型空心梁。单箱单室箱梁的变形包含弯曲挠度，还有剪切滞后和剪切作用分别引起的另外两种变形。本文基于长栅光纤布拉格光栅（LFBG）传感器改进共轭梁法（ICBM），以满足对单箱单室箱梁中两种附加变形的监测要求。本文还提出了一种在箱梁中布置合适的 LFBG 传感器的方法，以克服剪切滞后效应引起的应变波动对翼缘的影响。数值模拟结果表明，修正后的 ICBM 的理论监测误差通常为 0.3-1.5%，最大误差为 2.4%。通过 LFBG 传感器对单箱单室箱梁进行的加载实验表明，大部分实际监测误差在 6-8%之间，最大误差为 11%。