Finite Element Analysis And Precision Measurement On The Structure Of A12Meter Antenna

This paper focuses on the structural analysis and precision measurement of a12-meter antenna, which is an important part of a new generation radio telescope system-the Australia Square Kilometer Array Pathfinder (ASKAP) radio telescope project. Its working condition is complex, and its technical requirements, especially the reflector surface accuracy, are strict. To improve the structure of the antenna, a finite element analysis (FEA) should be utilized during the design process. In addition, the accuracy of the antenna should be measured to satisfy the design requirements and verify the results of FEA. Moreover, the reflector surface accuracy in the worst condition is estimated.Firstly, the finite element model of the antenna is established by using MSC. Patran. Considering the antenna’s working environment, such as its gravity load, wind load and solar radiation,19load cases are considered to meet the design requirements. The deformation and stress contour of the antenna’s main reflector panel in each load case is analyzed. Besides, the normal modes of the antenna are analyzed.Subsequently, considering the effect of the antenna’s gravity on the assembly errors, datas as the root-mean square (RMS) errors along the normal direction of the best fit reflector surface etc are obtained. Then a technical requirement index is given. In addition, some regularity of the deformation and stress of the antenna are found out in different postures and load cases.Finally,6operating conditions of the measurement program are selected, which are close to the corresponding conditions of FEA. The accuracy of the antenna’s reflector panel is measured using V-STARS system. Based on these data, the RMS errors along the normal direction are obtained by the measurement software MeroIn. These result shows that the FEA of the antenna’s structure is reliable. Further, the reflector surface accuracy in unachievable conditions can be also estimated by using the FEA results.With the work in this paper, the antenna’s structure is improved, and its technical requirements are satisfied.