基于时频域转换及雨流法的电子设备随机振动概率疲劳损伤预测

Probabilistic Fatigue Damage Prediction of Electronic Devices Under Random Vibration Based on Frequency⁃Time Domain Transformation and Rainflow Counting Techniques

针对电子设备随机振动疲劳损伤存在高度的不确定性问题,提出了一种基于频时域转换及雨流法的概率疲劳损伤预测方法,用于预测某航空电子设备在特定随机振动载荷条件下的疲劳损伤分布。通过采用“等效单元谱”近似计算,本文提出的方法能够在短时间内给出电子设备的损伤概率分布,且计算得到的疲劳寿命均值与试验结果吻合较好。因此在开展复杂功率谱密度(Power spectral density, PSD)载荷谱作用下的随机振动疲劳损伤计算时,具有计算效率高、工程适应性强等优势。

Aiming at the problem that the fatigue damage in electronic devices exhibits high uncertainty under random vibration loads,this paper proposes a probabilistic fatigue model based on frequency-time transformation and rainflow counting techniques to predict the fatigue damage distribution of an avionics device under specific random vibration loading conditions.The proposed method is capable of quickly providing the fatigue damage probability distribution,as well as the mean fatigue life which agrees well with the experimental observations.It has the advantages of high efficiency and strong engineering adaptability for random vibration fatigue damage predictions,especially under the circumstances of complicated power spectral density(PSD)loading conditions.