机翼主梁钛合金模拟件谱载疲劳寿命实验研究

Experimental Study of Fatigue Behavior of Titanium Alloy Wing’s Front-Beam Sample Under Spectrum Loading

确定某型飞机机翼主梁结构的使用寿命是保证该机使用安全的关键。本文对全机第一关键危险部位--机翼钛合金主梁下缘螺栓孔模拟件进行随机谱和程序块谱载荷下的疲劳寿命试验,获得了模拟件的疲劳裂纹形成寿命和疲劳全寿命,并对其寿命进行了统计处理和对比分析。结果表明,程序块谱较随机谱有更长的疲劳寿命。这说明随机谱比程序块谱要严重,对钛合金主梁模拟件的疲劳寿命有显著的影响。该结论可为机翼钛合金主梁构件疲劳寿命预测及疲劳设计提供试验依据。

Determining the service life of wing’s main beam of a certain type aircraft is the key to ensure aircraft safe service. Experiments were carried out to test fatigue life of a simulated specimens’ bolt hole at the lower edge of wing’s main beam made of titanium alloy under random spectrum and program spectrum, respectively. Fatigue crack initiation life and total fatigue life of simulated specimens were obtained and analyzed statistically and contrastively. Results show that the fatigue life is shorter under random spectrum than that under program spectrum, which indicates that the random spectrum has more serious effect on fatigue life of simulated specimens than the program spectrum. This conclusion may provide experimental evidence for fatigue life prediction and design of titanium alloy wing main beam.