The structural integrity of aircraft structures under vibratory loads is primarily evaluated through vibration tests, but it is necessary to predict the design life through vibration fatigue analysis at the design stage. Vibratory loads affect the durability of aircrafts by combining with the dynamic characteristics of their structures. The generation of stress spectrum in the vibratory loads, which must be calculated from power spectral density, is different from the calculations in the time domain. In this study, the stress spectrum generation and fatigue life were analyzed for various frequency bands with different characteristics. Through comparison of the fatigue life in the frequency domain and time domain, the characteristics of the stress spectrum estimation and optimal calculation methods are presented. It was confirmed that the frequency domain results tend to be more conservative in most cases than the time domain results, and Dirlik’s procedure estimates accurately in all frequency bands. A simple correction of the Narrow-band and Steinberg results could increase the accuracy of the fatigue life prediction.

飞机结构在振动载荷下的结构完整性主要通过振动测试来评估，但是有必要在设计阶段通过振动疲劳分析来预测设计寿命。振动载荷通过结合飞机结构的动态特性来影响飞机的耐久性。必须根据功率谱密度计算出的振动载荷中的应力谱的生成不同于时域中的计算。在这项研究中，分析了具有不同特性的各个频段的应力谱生成和疲劳寿命。通过比较频域和时域的疲劳寿命，给出了应力谱估计的特点和最优计算方法。可以肯定的是，在大多数情况下，频域结果比时域结果更为保守，并且Dirlik的方法可以在所有频带上准确估算。窄带和斯坦伯格结果的简单校正可以增加疲劳寿命预测的准确性。