使用载荷下的重谱能降低寿命不能降低疲劳分散系数

Heavy Spectra Under Operational Loads May Reduce Life But Not Fatigue Scatter Factor

本文在研究试验应力与疲劳分散系数分布规律的基础上,进一步研究给出:在使用载荷下高损伤的重谱可降低寿命,但不能降低疲劳分散系数的结论。这一研究结论与我国2010年新颁布的飞机结构强度规范规定的重谱可比平均谱取低一半的疲劳分散系数(从4降到2)相悖。为了验证这一研究结论的正确性,本文找到了在使用载荷下的重谱和平均谱的5种不同材料、不同结构模拟件的试验数据,用这些试验数据验证了本研究结论的正确性。

Based on research on the relationship between test stress and distribution of fatigue scatter factor,this paper concludes that heavy spectra with high damage under operational loads may reduce the life but not the fatigue scatter factor.This conclusion contradicts with the Aircraft Structural Strength Specifications published in China in 2010,which states that a fatigue scatter factor of half that for the mean spectra can be selected for heavy spectra（i.e.2 instead of 4）.To verify the conclusion of this paper,test data of heavy spectra and mean spectra under operational loads with 5 simulated items of different materials and structures are found and used and they all bear witness to its correctness.