Fault diagnosis of cable-net structure supporting active reflector of large radio telescope-FAST

作者：Jin Xiaofei^*; Fan Feng; Qian Hongliang; Shen Shizhao

来源：China Civil Engineering Journal, 2010, 43(6): 18-25.

• Active Reflector
• Aperture spherical radio telescopes
• Cable net structures
• Cable stress
• Computational results
• Early warning
• Fault diagnosis
• Fault diagnosis method
• Fault point
• Finite element model analysis
• Fundamental modes
• Hot-spot stress
• In-depth analysis
• Large radio telescope
• Moni-toring nodes
• Nodal force
• Non-parametric test
• Numerical simulation
• Pattern search method
• Quasi-static
• Real time
• Structural characteristics
• Structural elements
• Structural faults
• Structural response
• Structural safety

Fault diagnosis of a cable-net structure supporting the active reflector of Five-hundred-meter Aperture Spherical radio Telescope (FAST) was studied. Through in-depth analysis of structural characteristics, it was demonstrated that the cable-net structure of FAST is a quasi-static structure and the faults are local, and the fundamental modes of structural faults were subsequently determined with FAST telescope work features. The structural fault diagnosis was studied based on monitoring of cable stresses and coordinates of shift nodes. By monitoring structural "hot-spot stresses", the key structural elements were directly diagnosed by setting different criterions according to the benchmark status and the working status. By monitoring node coordinates, the deviation sequence with computational results was calculated. Against the inevitable errors of finite element model analysis and actual measurement, Walsh nonparametric test of the sequence and rapid computation of the unbalanced nodal forces were proposed to diagnose possible regional fault points for early-warning of real time structural safety, and subsequently, a pattern search method was proposed to diagnose specific modes and degree of structural faults by taking nearby elements as the diagnostic objects and the minimal deviation between measured and computational structural responses as the diagnostic target. The numerical simulation results show that the fault diagnosis method can be applied to FAST cable-net structure, and is effective and practical.

• 出版日期2010