分别在3种应力水平下对不同尺寸7050铝合金耳片试样进行疲劳试验，采用最小二乘法拟合得到了疲劳应力-寿命（S-N）曲线，研究了耳孔直径和耳片宽度比d/W（d为定值，24 mm；d/W=0.67.0.50，0.40）、耳孔纵向边距和横向边距比y/x（y/x=1.0，1.6）对耳片疲劳性能和断口形貌的影响。结果表明：在相同应力下，7050铝合金耳片的疲劳寿命随着d/W的减小（即W的增大）先延长后缩短；在较大的y/x值下，耳片的疲劳寿命较长；不同尺寸耳片的疲劳断口均呈典型的疲劳断裂特征，裂纹起源于表面和角部。

Fatigue tests at three stress levels were conducted on 7050 aluminum alloy lug samples with different sizes. The fatigue stress-life (S-N) curves of the lugs were obtained by the least square method. The effects of ratio of ear hole diameter to lug width d/W (d had a fixed value, 24 mm; d/W=0.67, 0.50, 0.40) and ratio of longitudinal margin to transverse margin of ear hole y/x (y/x=1.0, 1.6) on fatigue properties and fracture morphology of the lugs were studied. The results show that under the same stress, the fatigue life of 7050 aluminum alloy lugs increased first and then decreased with the decrease of d/W (namely increasing W). The larger of the y/x value, the longer of the fatigue life of the lugs. The fatigue fracture of the lugs with different sizes all had typical fatigue fracture characteristics. The cracks initiated on surfaces and at corners.