基于锚固区光纤布拉格光栅应变传感的智能缆索技术

Smart Cable Technology Based on Fiber Bragg Grating Strain Sensing in Cable Anchorage Zone

在分析了光纤布拉格光栅(FBG)应变传感及索力测量机理的基础上,根据静力学原理对缆索索身、连接筒、锚固区应变分布进行了分析,提出了一种基于锚固区FBG应变传感的新型缆索索力测量技术,并根据FBG工作稳定性原则,对FBG植入锚固区的位置进行了优化。设计了缩比模型实验,通过将FBG植于3根钢丝几何中心,保证了FBG工作的稳定性。实验结果表明锚固区内FBG所测应变值仅为锚固外FBG所测应变值的62%,且锚固区内部FBG中心波长与拉力值之间呈较好线性关系。证明了锚头内应变逐渐减小理论的正确性及该索力测量方法的可行性。

The mechanisms of fiber Bragg grating（FBG） strain sensors and cable tension measurement are analysised,and strain distribution of cable body,connecting tube,and anchorage zone are also analysised,and then a new cable tension measurement method based on FBG strain sensing of anchorage zone is proposed.Based on the stability principle of FBG,the embedded location of FBG is studied.Scale model experiments are carried out,and the FBG is embedded in the geometrical center of three steel wires to ensure the work stability of FBG.Experimental results show that the measured strain of anchoring region is only 62% of that of measured strain outside,and the central wavelength of the FBG in anchorage zone has a good linear relationship with the tension.The correctness of the theory and feasibility of the cable force measurement method are proved.