两种新型铝锂合金铆接结构细节疲劳额定强度研究
Studying Detail Fatigue Rating of Two New Aluminum-lithium Alloy Riveted Structures

针对飞机蒙皮铆接搭接结构,通过疲劳试验研究得到了两种新型铝锂合金Al-Li-S-4和2198-T8试件的细节疲劳额定值(DFR),同时借助扫描电镜观察疲劳裂纹的萌生和扩展行为。研究结果表明:Al-Li-S-4铆接结构的DFR值为102.24MPa,2198-T8的DFR值为83.09MPa,前者的铆接疲劳性能优于后者;两者疲劳断口有较大差异,前者断口比较平坦而后者相对粗糙,前者疲劳条纹更加细密,疲劳条带间距更小。
The detail fatigue rating (DFR) values of Al-Li-S-4 and 2524-T3 aluminum alloy structures are measured by fatigue experiments of riveted lap joints. The fatigue crack initiation and propagation behavior are observed by scanning electron microscopy. The results indicate that the DFR value of Al-Li-S-4 alloy is 102.24 MPa and the 2198-T8 alloy is 83.09 MPa, so the former has superior fatigue properties to the latter. There are some differences between Al-Li-S-4 and 2198-T8 on the fatigue fractography, and the former is flat and the latter is relatively rough, and the interval of fatigue striations of Al-Li-S-4 material is closer and finer