基于FBG传感技术的管道曲率监测试验研究

在地下盐穴储气库的建设过程中,建腔管柱容易 因为恶劣的工作环境而弯折。利用若 干特定排布在管道外壁上的光纤布喇格光栅(FBG)可以测量管道的弯曲形状,但管道直径会 影响弯曲重建的精度。为了找到重建精度与管道直径的关系,本文利用粘贴在管壁的同一素 线上的FBG对管道弯曲重建进行了有限元模拟和检测试验,将有限元结果和试验结果进行了 对比,并进行了误差分析。试验结果表明,FBG可以实现对弯曲管道的形状重建,在同样壁 厚的管道中,随着管道直径的增加,管道挠度的相对误差随着直径的增大由负向正增大。直 径为32 mm的管道在弯曲时的挠度相对误差靠近0点,在测试的4种不 同直径的管道中,弯曲重建效果最好。

Experimental research on pipeline curvature monitoring based on FBG sensing tech nology

During the construction of underground salt cavern gas storage,the ca vity-building pipes are easy to bend due to the harsh working environment.A co m bination of several fiber Bragg gratings (FBGs) with a specific arrangement on t he outer wall of the pipe can be used to measure the bending shape of the pipe, but the pipe diameter will affect the accuracy of the bending reconstruction.In order to find the relationship between reconstruction accuracy and pipe diamete r,this paper used FBGs which is pasted on the same plain line of pipe wall to i nvestigate pipeline bending reconstruction based on finite element simulation an d sensing experiment,the finite element simulation results are compared with th e experimental results,and the error analysis is carried out.The test data sho ws that FBGs can realize the bending reconstruction of the pipe shape,and for t he pipes with the same wall thickness,as the pipe diameter increases,the relat ive error of the pipe deflection increases from negative to positive as the diam eter increases.The relative error of the pipe deflection with a diameter of 32mm when bent is close to 0point,among the 4different diameter pipes tested,t he bending reconstruction effect is the best.