光纤光栅传感器在500 m口径球面射电望远镜工程索网施工阶段的应用

摘要

500 m口径球面射电望远镜(FAST)的主动反射面系统由圈梁、反射面单元、主索网及下拉索、促动器和地锚等组成,工程索网施工阶段会对支撑索网结构的圈梁及格构柱结构产生复杂多变的应力影响.为实现对圈梁及格构柱结构精准的应力监测,将光纤光栅传感器应用于圈梁及格构柱结构的索网施工过程监测中.介绍了传感器原理、测点布设、数据采集及数据分析方法.根据 FAST 索网施工过程监测的特点,基于3σ准则提出了一种新的异常数据处理方法,并利用该方法进行异常数据的分析与剔除.对实测数据进行分析,结果表明,在索网施工过程中圈梁测点的应力始终小于安全值201．5 MPa,格构柱测点的应力也一直处于安全范围内,且随着索网施工的进行,其应力变化具有一定的规律性.该光纤光栅传感器监测方法在FAST索网施工阶段得到了良好的应用.%Active reflector system of FAST consisted of ring beam,reflector unit,main cable and downhaul,actuator and anchor etc.During the construction phases of cable net,there would produce complex stress factors for the ring beam and lattice column which supported cable net structure.In or-der to achieve precise stress of the ring beam and lattice column structure,during the construction processes of cable network,this paper presented fiber grating sensors for monitoring the ring beam and lattice column structures.The principles of the sensor,measuring point layout,data collection and analysis methods were introduced.A new exceptional data processing method was proposed ac-cording to features of construction monitoring and 3σcriteria.This method was used to analyze and e-liminate abnormal data.Then the measured data were analyzed,the results show that the cable net-work construction process stresses of the ring beam measuring points are always less than the value of the security 201.5 MPa,the stresses of measuring points of lattice column are in the safe range,and with the progress of construction of the cable network,this paper found changes in the stresses with a certain regularity.This method of monitoring stress with fiber grating sensors is a good application in the FAST cable network construction phase.