大型射电望远镜天线副面调整机构完整刚度模型及微位移分析

基于并联机构的影响系数法和虚功原理构建天线副面调整机构的完整刚度模型。该模型综合考虑主被动关节弹性变形和外力/力矩的影响，且给出二阶影响系数矩阵具体的转置形式。构造单分支支链的轴向线刚度模型，考虑虎克铰和球铰对分支杆轴向刚度的影响。通过引入变动参数求解得到副面调整机构在定平台可动时的完整刚度矩阵，充分解决副面调整机构在空间任意位姿下刚度矩阵的计算问题。通过最简刚度模型、本体刚度模型和整体刚度模型三者对比，绘制副面调整机构在初始位姿下副面调整机构动平台中心随变动参数变化时的微位移曲线，并通过有限元软件验证了结果的正确性。研究内容为大型射电望远镜天线副面调整机构的结构设计与精度补偿奠定重要的理论基础。

Complete Stiffness Model and Micro-displacement Analysis for Large Radiotelescopeantenna Subreflector Adjusting Mechanism

The complete stiffness model of antenna subreflector adjusting mechanism (SAM) is constructed based on influence coefficient method of parallel mechanism and principle of virtual work. The model considers comprehensively the impact of elastic deformation of active-passive joint and external force/moment and gives the specific transposed form of the second order influence coefficient. The axial line stiffness model of single branched chain is constructed considering the effect of hooke hinge and spherical hinge on branch rod axial stiffness. The complete stiffness matrix of SAM is solved by introducing varying parameter on condition that the fixed platform is movable, which solves fully the stiffness matrix calculation problem of SAM in any spatial position and orientation. Through the comparative analysis among the simplest stiffness model, mechanism stiffness model and whole stiffness model, the micro-displacement curve of SAM moving platform center is mapped with the change of varying parameter in the SAM initial configuration, and the correctness is verified by the finite element analysis software at two limit configurations. The research content lays an important theory basis for the structural design and precision compensation of large radiotelescopeantenna SAM.