关键词: 环境障涂层, 双硅酸镜(YhDS):高速碰摩:周期峰值:Weibll模型:超限概率

Abstract: The extremely small blade tip clearance in aero-engines leads to occasional nub-impact faults between the bladesand the casing. To quantify the randomness of cyclic peak values and the probability of high loads during contin-uous high-speed rub-impact, high-speed rotor nub-impact tests were carried out on four ytterbium disilicateYhDS) environmental barrier coatings with different structural characteristics, The normal force signals wereegmented by rotor cyele, and the peaks over the whole cycle were extracted with the baseline corrected. Thepeak values were then fitted with a Weibull model, and the 95% upper-quantile rub-impact force Fas and theexceedance probability were calculated. The results show that the p values of the Kolmogorov-Smimnov (K-S) testare 0.837. 0.764, 0.782 and 0.635. all greater than 0.05. The Fos Values are 2706.19, 2 190.52, 2 046.44 and2 085.93 N, all more than 16% higher than the mean peak values, The Hertz theoretical rub-impact forces ofcoatings 2, 3 and 4 are 39.69%, 48. 50% and 45.69% higher than their Fas values. The study indicates that theWeibull model can accurately reflect the dispersion of cyclic peak values and the exceedance probability under agiven engineering load limit. It can therefore provide a basis for coating design that balances rub-impact load riskand coating performance.

Key words: environmental barrier coating, ytterbium disilicate (YbDS), high-speed rub-impact, cyclic peak value, Weibull
model, exceedance probability