巨型望远镜FAST 30m模型结构传感器优化布置

为了有效监测结构,研究巨型望远镜(FAST,Five-hundred-meter Aperture Spherical Telescope)30m模型结构——整体索网结构的传感器优化布置方法.FAST 30m索网结构监测内容包括环境荷载和结构响应,其中索应力、变位节点位移、结构振动是主要监测物理量.索应力监测传感器主要按照"热点应力"原则布设,综合考虑各照射源方向反射面变位后"热点应力"位置、按实际周围环境数值模拟各风向作用下风荷载计算的最大峰值响应位置以及球面基准态时索应力变化对结构整体刚度影响较大的位置;为使主动反射面精确定位,所有变位节点粘贴光学靶标,采用激光全站仪自动同步扫描其坐标以推算径向位移和切向位移;结构振动以风荷作用下主要参与振动模态为目标模态,基于有效独立法进行测点优化.

Optimal Sensor Placement of 30-meter Scaled Structure of Large Telescope-FAST

The optimal sensor placement of the cable-net structure supporting the active reflector of FAST(Five-hundred-meter Aperture Spherical Telescope) 30m model was studied.Environmental loads and structural responses of FAST 30m cable-net structure were monitored,taking the cable stresses,cable-net node displacements and structural vibration as the mainly monitored physical objects.Stress monitoring sensors were laid in accordance with the"ot-spot stress"rinciple,considering the hot-spot stresses locations after the movement of reflector in each irradiation direction,the maximum peak response locations under the wind loads in every direction which were gained by numerical simulations based on actual surroundings,and the locations where the cable stresses changed with a greater impact on the structural stiffness on the spherical benchmark status.;n order to accurately fix the active reflector,all nodes were pasted with optical targets so that the coordinates could be auto-sync scanned with laser total station instrument and the corresponding radial and tangential displacements could be subsequently calculated.;easuring points of structural vibration were optimized based on the effective independence method with the aiming modals which mainly participated in the structural vibration under wind loads.