A prediction method to improve the accuracy of fatigue life prediction for engine mounts is proposed, which is based on wavelength packet analysis and stress power density. The stress power spectral density of the fatigue failure site is simulated and experimentally verified through transfer function theory. The Dirlik method and bandwidth coefficient are used to determine fatigue life. The main frequency bands that affect life expectancy are analyzed through wavelet packet theory. And a bench test is performed to verify the results of different fatigue life prediction methods. Results revealed that wavelength packet analysis yields low relative errors between the predicted and experimental life expectancy. The prediction method based on wavelength packet analysis has high accuracy and will improve the results of the fatigue life prediction for key automobile components.
本文提出了一種基於波長包分析和應力功率密度的發動機懸置疲勞壽命預測方法。利用傳遞函數理論,對疲勞失效部位的應力功率譜密度進行了類比和實驗驗證,採用Dirlik法和頻寬係數確定疲勞壽命。同時利用小波包理論分析了影響壽命的主要頻帶,並且通過台架試驗驗證了不同疲勞壽命預測方法的結果。結果表明,波長包分析得到的疲勞壽命相對誤差較小。基於波長包分析的疲勞壽命預測方法具有較高的精度,將提高汽車關鍵零部件疲勞壽命預測效果。