多序多工位下复杂航空结构件装配变形产生、传递与演变规律

Assemble of complex aircraft components generally includes several multilevel assembly stage including:large weakly rigid structure - component - big component-final assembly, and each level contains many assemble procedures.Aiming at local deformation and global distortion caused by poor rigidity location clamp and too much hole making and riveting in the course of assemble joint of large-scale aerospace structure,with the help of experiment research, mechanical modeling and numerical calculation, based on accurate construction of constitutive relation model of aeronautical materials and continuous processing of dynamic physical simulation model, this paper will study positioning accuracy under the condition of poor rigidity and optimal method of over-positioning, rationality of clamping and optimization modelling of clamping; This paper will also reveal additive effect of global distortion caused by repeated process of drill riveting,and construct overlapping calculating method of high efficient global deformation；By synchronizing solution of the complex stress field and rivet deformation（quantity）in the automatic drilling and riveting process, it can create the relation model between rivet deformation and process parameters, optimize the process parameters and process route for both the single-point riveting(clamping, drill, riveting, milling) and the quantity riveting points consecutive calculation, meanwhile seek the strategy of deformation compensation, finally establish a complete accuracy assurance for the automatic drilling and riveting. This can provide a scientific and quantitative basis for assemble process planning, change the blind process test and process route setting method, and afford general guidelines for large size weakly rigid structure in the assembly deformation control problem.

针对复杂航空结构典型装配过程中因弱刚性件不合理定位与夹紧、大量制孔与铆接、多工位（组件-部件-总装配）间装夹状态变换等导致的局部变形缺陷、整体扭曲和协调错位等变形行为，借助于实验研究、力学建模、数值计算等方法，研究弱刚性构件定位原理、夹紧过程数学建模及变形产生机理，结合试验研究准确描述航空结构和连接件材料的本构关系，研究构建单点多工序（压紧、钻孔、铆接等）及大量钻铆等连续装配连接过程的动态物理仿真模型，揭示大量重复装配连接引起的整体变形累加效应，构建高效的整体变形高效计算及工艺参数优化、路径优选方法；在多工位装配衔接状态：基于误差流理论，研究多工位装配变形传递、扩散与演变规律，形成状态多变的不连续装配过程的变形传递分析与协调变形误差溯源方法。通过综合研究，构建装配变形场，建立多层次间装配变形误差溯源理论与方法，为复杂航空结构装配变形控制提供普遍指导原则，为工艺规程制订提供科学量化依据。

针对弱刚性航空结构件典型装配铆接过程中产生变形行为：. 首先，系统研究了弱刚性构件的定位原理、夹紧过程数学建模及其定位变形产生机理，建立了相应的定位正确性数学模型，推导了相关判据，提出了一种关键定位特征约束下的“(N1+N2)-2-1”弱刚性件定位准则，构建了一种基于CSA-OK代理模型的定位点数量与布局反求模型，并以变形最小为目标，形成了一种区间关键定位特征约束下结合FPA-SVR 代理模型与 NSGA-II进化算法的航空薄壁件定位布局多目标优化方法；. 其次，通过霍普金森压杆动力学实验构建了航空结构和连接件材料的J-C本构关系模型，建立了一种单点多工序铆接全过程动态物理仿真模型，包括基于钉杆镦头不均匀变形和主应力法的压铆力计算模型，基于接触变形理论的钉孔受挤压位移分布表达式，求解了压铆力撤除、钉孔受限回弹残余应力场分布，给出了铆接后被连接件的变形状态分布，发现材料屈服强度是对变形影响最大的因素；. 再次，提出了一种用于实现钉孔周围复杂应力状态区域与全局简单应力状态区域分析的壁板“体-壳”连接建模方法，建立了“局部-整体”映射模型和相应的铆接变形累加效应数值计算模型，就大量重复装配连接过程的变形累积规律进行了仿真计算和实验研究，发现边界条件固定时，板料间会产生间隙，一端自由时，出现翘曲现象，选择跳铆时，能显著减小铆接变形，且当跳跃铆钉数为2时，变形最小。进一步以提高壁板铆接变形均匀性和平滑度、路径最短和变形最小为目标，提出了一种基于Kriging-PSO的铆接工艺参数优化和蚁群遗传算法的路径规划模型，得出了铆接路径和变形的帕累特最优解；. 最后，对多工位间装配变形的传递、耦合与演变规律进行了研究，构建了一种多工步定位、夹紧和装配偏差传递的状态空间模型，制订了以关键协调特征处协调变形最小为目标的装配协调基准和协调方案优化方法；. 结合型号产品壁板比例件铆接试验，验证了本项目研究成果的正确性和有效性，并为为复杂航空结构装配变形控制与工艺规程制订提供了理论基础和科学量化依据。