金属飞机结构胶接修理技术地研究.pdf

南京航空航天大学硕士学位论文— I —摘要为减轻结构重量又保证足够强度,飞机结构常做成以铝合金为主要材料的薄壁结构。在长年的使用中,结构承载着复杂交变的载荷和环境的影响,飞机难免引起裂纹和腐蚀,势必对结构强度造成危害,影响飞行安全。与传统的焊接、铆接、螺接修理方法相比,飞机金属结构的胶接修理方法因其能降低结构的应力集中水平,提高使用寿命,简化工艺等优点,成为当今国内外正在深入研究的一项经济而有效的飞机结构延寿方法。本文采用理论和试验分析的方法,研究了金属飞机结构胶接修理的几项基本技术。首先研究金属结构胶接的基础理论以及表面处理对胶接耐久性的影响;其次总结铝合金表面处理技术,着重研究波音公司推荐使用的铝合金表面磷酸阳极氧化处理工艺——磷酸局部阳极氧化(PACS)和磷酸非槽式阳极氧化(PANTA),以及最新的表面处理技术——Boegel;分别采用PANTA以及PACS对LY12CZ铝合金试验件表面进行预处理,观察其表面微观形貌。对试验件进行力学试验,测量拉伸剪切强度,做出比较。最后结合MIL-HDBK-337《航空航天结构胶接修理》和波音结构修理手册,介绍铝蜂窝结构损伤的典型修理,试图把外国民用飞机成熟的金属结构胶接修理技术成功运用到我国飞机实际修理中。关键词:金属结构,胶接修理,表面处理,磷酸阳极氧化,铝合金金属飞机结构的胶接修理技术研究— II —ABSTRACT In order to reduce the weight and ensure enough strength, aluminum alloy are abundantly used in the aircraft structure. During the long term usage, cracks and damages occur unavoidably. Compared to the traditional repair methods, such as welding, riveting and bolting, bonded repair of metallic structure has been recognized as an economical and efficient method to extend the service lives of damaged aircrafts for it can reduce the concentrated stress of the structure, simplifier the process. In this thesis, some critical technologies of bonded repair of metallic structure under field situations have been investigated. The main works of this paper are as follows: Firstly,the basic theories for metal bonding have been introduced and the influence of surface treatment for the bonded structure durability has been studied and summarized. Secondly, the surface treatments for metallic structure have been introduced, especially the method mended by pany for aluminum alloy have been discussed. Two versions for in-field use phosphoric acid anodization process, Phrosphoric Acid Non-tank Anodizing (PANTA) and Phrosphoric Acid Containment System (PACS), and the new surface treatment-Boegel have been studied. The microcosmic shapes had been observed and the mechanical tests were conducted to study the performance of phosphoric acid anodization for bonded repair. Finally, according to MIL-HDBK-3