Bolt joint and riveting joint are the main connection methods of the aircraft structure.Because of severe structural stress concentration at the hole edge,hole structures are prone to fatigue fracture.Therefore,improving the fatigue strength of the connection hole is a key technique that the aviation industry is generally concerned about.Hole cold expansion is the most widely used technique for hole anti-fatigue manufacturing.In this paper,the technology of hole cold expansion,the strengthening mechanism,the factors influencing the cold expansion process,the effect of service conditions on anti-fatigue gain of cold expansion,and the effect of re-cold expansion on pre-fatigued hole are summarized.Based on analysis of current status of research on cold expansion and practical needs of the aviation industry,some prospects and recommendations for hole cold expansion in future study are given.%螺接和铆接是飞机结构主要连接方法,因为孔边存在严重结构应力集中,孔结构很容易发生疲劳断裂,影响航空安全性和可靠性,因此,提高连接孔疲劳强度是航空业普遍关心的关键技术问题之一.孔挤压是当前国际上应用最为广泛的连接孔抗疲劳制造技术,具有不改变结构设计、材料,不增加飞机重量,成本低、效果好等优势.本文从孔挤压技术发展、孔挤压强化机理、孔挤压影响因素、服役条件对孔挤压疲劳增益影响以及再挤压对预疲劳连接孔疲劳增益影响等5个方面进行了较为系统的总结,并基于孔挤压技术研究现状和航空工业发展实际需求,分析了当前研究的不足,提出了一些未来研究孔挤压技术需要关注的方向.
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