大型复合材料构件连接装配二次损伤及抑制策略

在分析复合材料构件成型和制孔过程中产生缺陷的基础上,从构件成型质量、连接孔加工质量和连接孔配合质量3个方面研究了影响装配应力分布的主要因素及其影响规律。研究发现,装配间隙为1.0mm时,连接区最大应力可达537MPa;垂直度误差为1°时,连接区最大应力超过300MPa;连接孔同轴度误差为0.03mm时,连接区最大应力可达443MPa。装配应力过大引起材料内部成型缺陷和制孔损伤的进一步扩展,形成二次损伤,严重影响装配质量。通过合理设计结构和铺层、优化成型工艺和制孔参数,可以减少初始损伤;采用自动化装配技术、优化工装结构、合理安排装配工序和应用填隙补偿工艺降低装配应力,进而有效抑制二次损伤的诱发与扩展,为实现大型复合材料承力构件的高质量精准连接装配提供理论方法和技术支持。

Secondary Damage and Its Inhibition Strategies on Joint Assembling of Large-Scale Composite Components

Based on the analysis of the defects induced in the process of forming and drilling of composite com-ponents, the main factors influencing the distribution of assembly-induced-stress and the influence law are investigated from three aspects, including the forming quality of components, the machining quality and fitting quality of connec-tion hole. It indicates that the assembly-induced-stress of connection zone can reach 537MPa as assembly gap is 1.0mm while it is over 300MPa with 1° perpendicularity error. Moreover, when the coaxiality error of connecting holes is 0.03mm, the assembly-induced-stress exceeds 443MPa. Large assembly-induced-stress results in the propagation of the defects induced in forming and drilling and secondary damage, thus severely diminishing the assembly quality. There-fore, ef-fective inhibition strategies for the initiation and propagation of secondary damage are put forward from the two aspects of reducing initial damage with reasonable design of structure and layers, optimization of forming process and drilling parameters; and simultaneously declining assembly-induced-stress by automated assembly technology, fixture device optimization, reasonable arrangement of assembly process and application of shimming compensation process, which provide theoretical approaches and technical support for high-quality and precise assembling of large-scale com-posite bearing components.