LY12CZ铝合金铆接件微动损伤防护技术研究

 本文详细地分析了LY_(12)CZ铝合金铆接件微动损伤的微观特征以及各种搭接表面处理方法对疲劳强度的影响。试验结果表明:对搭接表面采用恰当的处理方法,铆接件的疲劳寿命一般均有不同程度的提高,其中,胶铆结构的采用是防止铆接件产生微动损伤的有效措施。当轴向交变应力σ_(max)=125MPa以下时,胶铆试件的疲劳寿命比干涉铆接的疲劳寿命提高60％以上。

A STUDY OF THE EFFECTIVEIY PROTECTIVE MEASURE TO PREVENT FRETTING DAMAGE OCCURRED IN HIGH STRENGTH ALUMINIUM-ALLOY RIVETED FASTENER

Many papers have been presented to introduce the deleterious effects of fretting damage on fatigue strength: reductions of over 50% are reported for simple coupon type specimens. In the aircraft failure investigating, the presence of fretting damage on the failure areas is also frequently noticed, especially the high chance of fretting damage occurrence appears in the aircraft structure where two pieces of material are connected by rivets,bolts, pins and interference fit. To what extent this damage effects on airframe structural life has not been determined, but is certainly a serious and noticeable problem.The microcosmic characters of fretting damage of high strength aluminum-alloy riveted fasteners and the effects of different type of treatments applied to the faying surfaces on the fatigue strength are analysed in details. The results of tests show that the fatigue life of riveted fasteners can be generally increased with different degree if an appropriate type of treatment is employed for the faying surfaces. The method of bonded and riveted joint studied in the paper is the effectively protective measure to prevent fretting damage occurred in riveted fasteners.When the axial interchangeable stress σmax is less than 125MPa the fatigue life of the bonded and rivetted joint specimen is over 60% higher than that of the interference riveted joint specimen.