An integrated framework of surface accuracy prediction for clearance-affected extendible support structures with dimensional deviations and elastic deformations

The surface accuracy of the extendible support structure (ESS) greatly influences the imaging resolution of spaceborne antennas. Therefore, considering dimensional deviations, joint clearances and elastic deformations comprehensively, this paper proposes an enhanced deterministic prediction framework to analyze the surface accuracy of the spatial overconstrained ESS. On the one hand, unlike the previous studies which neglect the elastic deformations and connection constraints of antenna panels, these factors and the link flexibility are fully incorporated into the constructed deformation analysis model via the absolute nodal coordinate formulation. Meanwhile, the elastic forces triggered by dimensional deviations and structural deformations are also determined with the skills of invariant matrices for the flexible elements. On the other hand, accounting for axial and radial clearances in spatial revolute joints, the contact conditions and contact forces are described comprehensively, and the contact detection strategy is further put forward for all potential contact scenarios. Afterwards, an integrated accuracy prediction framework is developed to quantify the interaction among dimensional deviations, joint clearances and elastic deformations. Finally, the dynamic segmentation modeling is proposed to determine the surface accuracy of the ESS, and the experiments verify that the developed method is of good prediction accuracy.