摘 要:根據試驗要求,對葉片在樣本較少情況下測定其疲勞極限σ-1和S-N曲線。通過振動疲勞試驗的方法進行研究,試驗采用升降法選擇所施加振動應力的水平,采用異方差回歸分析方法進行疲勞試驗數據的分析。最后獲得葉片材料的均值S-N曲線和置信度為95%、可靠度為99.9%的P-S-N曲線,并得到各自曲線上的疲勞極限σ-1。此方法保證試驗的順利進行并且具有較高的可靠性,對于小樣本測定材料的S-N曲線具有較好的實用價值。
關鍵詞:疲勞極限;小子樣測試;S-N曲線;升降法;異方差回歸分析方法
文獻標志碼:A 文章編號:1674-5124(2015)12-0124-04
Studies on small sample test method for blade S-N curve
ZHANG Bing1,2, CHEN Liwei1, CHEN Yongxiang1, YAN Xudong2, ZHAO Shuaishuai2
(1. Beijing Institute of Structure and Environment Engineering,Beijing 100076,China;
2. Tianjin Aero-space Relia Technology Co.,Ltd.,Tianjin 300462,China)
Abstract: To determine the fatigue limit σ-1 and S-N curve of blades with few small samples as the test requirements. Vibration fatigue test, that is, the level of vibration stress was fixed via up-down method and the test data was analyzed through variance regression. The S-N curve of mean value and P-S-N curve with 95%-confidence coefficient and 99.9%-reliability of blade materials have been obtained, so as the fatigue limit σ-1 of each curve. The method ensures the smoothness and reliability of the test and has a guiding significance in determining the S-N curve of materials through small sample test.
Keywords: fatigue limit; small sample test; S-N curve; the up and down method; the variance regression analysis method