航天大型薄壁结构装配制造尺寸精度预测与控制方法

Deviation Prediction and Control of Large Thin-Walled Structures in Spacecraft Manufacture

大型薄壁结构的弱刚性导致其在制造过程中变形是影响尺寸精度的主要因素,如何对加工和装配过程零组件的偏差场进行精确预测与控制是提升制造质量、改进工艺参数的关键。本文针对大型薄壁结构制造与装配过程偏差场特性进行研究,提出适用于航天大型薄壁产品装配过程偏差场预测与控制方法。以基本变形模式的线性组合构建大型薄壁结构空间偏差场,考虑大型薄壁结构装配过程内应力的协调变形,以零件与装配体之间基本变形模式的映射关系建立大型薄壁结构装配过程偏差场预测模型。基于零件基本变形模式对装配体偏差的贡献量化值进行薄壁结构装配过程偏差溯源,提出两步寻优方法求解零件特定基本变形模式的最优控制点集,以最优控制点集的偏差调整实现大型薄壁结构装配过程的偏差控制,为航天大型薄壁结构装配过程的尺寸精度预测与控制提供理论基础与技术指导。

The deformation in the manufacturing process for large thin-walled structures is the main factor affecting the dimensional accuracy due to their weak structural stiffness.The accurate prediction and control of the deviation field of parts in the manufacturing and assembly processes are the key to improve the manufacturing quality and process parameters.In this paper,the deviation description and propagation characteristic in the manufacturing and assembly processes of large thin-walled structure are studied.A deviation prediction and control method of large thin-walled structures is proposed.A linear combination of the basic deformation patterns is used to describe the spatial deviation field of large thin-walled structures.Considering the compatible deformation of the internal stress during the assembly process,a deviation prediction model of large thin-walled structures is established based on the relationship of the basic deformation patterns between the parts and the assembly.The contributions of the basic deformation patterns between the parts and assembled structures are calculated to reveal their internal relationship.The optimization method is used to solve the optimal control points of the basic deformation patterns,and the assembly deviation control of large thinwalled structures is realized by the adjustment of the deviations of the key points.The results may provide theoretical basis and technical guidance for the dimensional accuracy prediction and control for large thin-walled structures of aerospace products.