射电天文研究室知识库

研制满足单面板精度为0.07mm(RMS)的高精度面板,是制造高精度新疆110m射电望远镜(QiTai Radio Telescope,QTT)天线的关键技术之一.QTT基于主动保形技术,为满足天线结构与性能优化需求,在保证面板精度同时面板数量需要控制.天线面板越大面型精度提升越困难,制造高精度大面板将面临严峻挑战.基于蜂窝夹层结构、蒙皮筋条结构,采用改进负压成型工艺,进行了高精度面板成型试验研究,试验结果表明面积小于1.5 m~2面板精度能满足需求,就目前国内工艺水平来看已无法研制更大面积单面板(如5 m~2).为了满足QTT需求,对组合面板结构进行了初探.仿真了采用传统以及过渡子桁架,基于刚性和等柔性支撑两种方式以及采用传统拼接组合面板形式.结果表明采用过渡子桁架方式面板精度、数量能够满足需求,但复杂子桁架结构研制成本高,且造成组合面板重量增加,会导致天线结构设计复杂影响天线性能;传统拼接组合面板结构虽然满足精度需求但其面板数量没有控制在理想范围内.展望了未来提高面板精度需要进一步开展的工作.

It is one of the key technologies to manufacture the Xinjiang 110 m radio telescope (QTT) antenna with high-precision and has the single panel accuracy of 0.07 mm (RMS). QTT is a homology structure based on active surface meaning that the number of panels should be kept to minimum, while ensuring the panel accuracy, in order to meet the requirements for antenna structure and performance optimization. The difficulty for improving the surface precision increases as the panel size increases, creating numerous challenges in fabrication of large panel with high precision. Based on the honeycomb sandwich structure and the aluminum skin structure, the improved negative pressure forming technology is used to carry out high precision panel forming test. The test results show that a panel with area less than 1.5 m² meets the requirement. However, the current craft for panel fabrication in local China is unable to develop a single panel with area larger than 5 m². In order to meet the demands of QTT, the structure of combination panel is studied. Based on both rigid and equal flexible supports structure, the traditional and transitional sub-frame combination panel forms and traditional joint combination panel are simulated. The results show that the transitional sub-frame method could meet the required precision and quantity, but the complicated sub-frame structure attracts high development cost and increases the overall weight of the panel, which will also lead to increased complexity in antenna design and influence electrical performance. In contrast, although the traditional joint-combination-panel structure meets the precision requirement, the number of panels is not controlled within the ideal ranges. Future plan for improvement of the panel accuracy needs to be developed.