Fatigue life prediction of the aluminum box for aircraft parts turnover based on the rainflow counting method
摘要
Aircraft parts are typically transported in metal aluminum boxes, which require a time-consuming fatigue life test to determine if their service life can meet the actual needs. However, direct prediction of the fatigue life of these boxes is challenging and costly due to their large sizes. Accordingly, an economical and intuitive fatigue life analysis method for large packaging boxes must be proposed. This study proposed an accelerated fatigue life prediction method to improve the excitation level of aircraft parts for turnover aluminum boxes. First, the stress changes at the most hazardous point of the aluminum box for aircraft parts turnover is obtained through kinetic analysis. Second, the rainflow counting method is used to count the load time course, analyze the distribution of the amplitude of stress and mean, and create the load spectra. Third, the modified P–S–N curve of the turnover aluminum box is obtained, considering the structural parameters and fatigue limit value of the turnover aluminum box. Finally, the Palmgren–Miner linear cumulative damage theory is applied to forecast the fatigue life of aluminum boxes used for airplane parts turnover. Results show that, under the 0.05 significance level, the amplitude and the mean of the stress are independent of each other, and the stress amplitude is Weibull distributed with a shape parameter of 1.04 and a scale parameter of 7.26. The average stress value has a mean of 0.06 and a standard deviation of 2.39, which is normally distributed. The Miner’s rule of the fatigue life of the turnover aluminum box is predicted to be 16.4 years. The research in this study can provide an analytical method for fatigue life prediction under different transportation environments and provide a reference basis for judging the cycle life of metal packaging boxes.