Rotational fatigue analysis on Shanghai 65-m fully-steerable antenna structure during its normal operation

Abstract

Structural fatigue property of Shanghai 65-m fully-steerable antenna structure is analysed. According to the active fully-steerable working pattern, the typical fatigue stress piece is put forward based on simple sampling and decomposed by real-time rain flow counting algorithms. Subsequently, the fatigue lives of pitch mechanism bearings were computed by miner linear accumulative damage criterion. What’s more, in a complete cycle of dynamic observation, the shear force and axial force of high strength friction grip bolts for all of the supporting nodes are extracted and counted aiming at each pitching angle. As a result, fatigue analysis is carried out on the supporting nodes of the back-frame structure connected with the pitching mechanism. Last but not the least, finite element refinement model is conducted for the contact part between antenna wheels and the rail. Based on contact fatigue curve spectrum, the contact fatigue existing between the antenna structure roller and the track is analysed. The results show that the fatigue life of the whole antenna structure can meet the safety requirements in the design reference period which is intended to be 30 years. This systematic fatigue analysis procedure, method and results can provide valuable references for design, construction and maintenance of such similar fully-steerable antenna structures in future.