Monitoring Cable Force of FAST Project Based on Fiber Bragg Grating Sensor External Installed on Anchorage Zone

doi:10.3901/JME.2017.17.023

Abstract

Abstract: The five-hundred-meter aperture spherical radio telescope (FAST) is a major scientific project in China. The cable net is the main support structure and angle adjusting mechanism of reflector, which effective real-time health monitoring to the cable force plays a vital role in evaluating the safety and maintenance of FAST. A measurement method for cable force by coupling the fiber Bragg grating (FBG) sensor on the surface of cable anchoring cup is presented. The axial stress distribution of the anchoring cup is analyzed theoretically, which relationship with cable force is derived. FBG sensor with measure range of 1 500μɛ is selected and installed along the axial direction on the outer surface of the anchoring cup near the bigger end of inner cone hole. The safety, durability and temperature integration of sensor are secured by the special installation base and protective shell. 316 cables are installed FBG sensors to monitor the cable tension force and each senor is effective after cable net knitting. During the adjustment of the cable net, the measured data of the FBG sensors of the edge cable of the B area is compared with the force measuring by the adjustment system, and the relative error is less than 5%, which meets the engineering requirements.

Key words: anchorage zone, cable force monitoring, fiber Bragg grating sensor, radio telescope, temperature compensation

CLC Number:

TN253
TH743

ZHU Wanxu, QIN Heying, LI Juze, OU Jinping. Monitoring Cable Force of FAST Project Based on Fiber Bragg Grating Sensor External Installed on Anchorage Zone[J]. Journal of Mechanical Engineering, 2017, 53(17): 23-30.

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