摘要
A cable net structure is selected to support its reflecting triangular aluminum panels of FAST(five-hundred-meter aperture spherical radio telescope).To ensure the security and stability of the supporting structure,cable force of typical cables must be monitored on line.Considering the stringent requirements in installation,accuracy,long-term stability and EMI(Electromagnetic interference),most of the commonly used cable force measurement methods or sensors are not suitable for the cable force monitoring of the supporting cable-net of FAST.A method is presents to accomplish the cable force monitoring,which uses a vibrating wire strain gauge to monitor the strain of linear strain area at the anchor head.Experiments have been carried out to verify the feasibility.The method has a series of advantages,such as high reliability,high accuracy,good dynamic performance and durability,easiness of maintenance,technical maturity in industry and EMI shielding.Theoretical analysis shows that there is a linear relationship between the cable body force and anchor head surface strain,and experimental results proves a good linear relationship with excellent repeatability between the cable body force and anchor head surface strain measured by the vibrating wire strain gauge,with a linear fit better than 0.98.Mean square error in practical measuring is 2.5t.The relative error is better than 4%within the scope of the cable force in FAST operation which meets practical demand in FAST engineering.
A cable net structure is selected to support its reflecting triangular aluminum panels of FAST （five-hundred-meter aperture spherical radio telescope）. To ensure the security and stability of the supporting structure, cable force of typical cables must be monitored on line. Considering the strin- gent requirements in installation, accuracy, long-term stability and EMI （Electromagnetic interfer- ence）, most of the commonly used cable force measurement methods or sensors are not suitable for the cable force monitoring of the supporting cable-net of FAST. A method is presents to accomplish the cable force monitoring, which uses a vibrating wire strain gauge to monitor the strain of linear strain area at the anchor head. Experiments have been carried out to verify the feasibility. The meth- od has a series of advantages, such as high reliability, high accuracy, good dynamic performance and durability, easiness of maintenance, technical maturity in industry and EMI shielding. Theoreti- cal analysis shows that there is a linear relationship between the cable body force and anchor head surface strain, and experimental results proves a good linear relationship with excellent repeatability between the cable body force and anchor head surface strain measured by the vibrating wire strain gauge, with a linear fit better than 0.98. Mean square error in practical measuring is 2.5t. The rel- ative error is better than 4% within the scope of the cable force in FAST operation which meets prac- tical demand in FAST engineering.
基金
Supported by the National Natural Science Foundation of China(No.11173035,11273036)
