Structural response of the FAST cable-net at large zenith angles
ZHANG Ningyuan1,2, LUO Bin1,2, SHEN Yuzhou1,2, JIANG Peng3,4, LI Hui3,4, LI Qingwei3,4
1. Key Laboratory of Concrete and Prestressed Concrete Structures of Ministry of Education, Southeast University, Nanjing 211189, China; 2. National Prestress Engineering Research Center, Southeast University, Nanjing 211189, China; 3. National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100101, China; 4. Key Laboratory of FAST, Chinese Academy of Sciences, Beijing 100101, China
Abstract：The five-hundred-meter aperture spherical radio telescope (FAST) is supported by a cable-net structure with active shape changing of the reflecting surface realized by hydraulic actuators controlling the cables. The strength and fatigue life of the cable-net have not been verified for large zenith angles and large source changes. The cable-net analysis model was modified based on current monitoring data to analyze the structural response of the cable-net for shape-changing operations at large zenith angles. A modified focal ratio and shape-changing strategy were developed to reduce excess stresses and stress amplitude at large zenith angles. The structural response analysis were carried out during the source-changing process when changing the zenith angle. The results show that the total transition zone always involves the 150 cables in the outermost ring for large zenith angles, with this result not being affected by temperature. The use of modified focal ratios can significantly reduce the number of excess stress conditions. A safe shape-changing strategy ensures that the surface cable stresses and stress amplitudes remain within the stress limits while still maintaining the surface accuracy. Source changing from one large zenith to another large zenith angle is the most unfavorable condition.
张宁远, 罗斌, 沈宇洲, 姜鹏, 李辉, 李庆伟. FAST索网大天顶角工况下结构响应分析[J]. 清华大学学报（自然科学版）, 2022, 62(11): 1809-1815,1822.
ZHANG Ningyuan, LUO Bin, SHEN Yuzhou, JIANG Peng, LI Hui, LI Qingwei. Structural response of the FAST cable-net at large zenith angles. Journal of Tsinghua University(Science and Technology), 2022, 62(11): 1809-1815,1822.
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2022, Vol. 62 
