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缺陷容限设计方法充分考虑直升机的特点,将损伤容限设计思想巧妙地应用于直升机的设计中,通过缺陷容限值保证关键动部件的服役安全。本文采用疲劳极限反推的方法测试了三种尺寸的缺陷容限门槛值,分别采用有限元法和Y.Murakami公式计算缺陷容限门槛值,结果表明:含有265μm,374μm,480μm缺陷尺寸的三种试件缺陷容限门槛值基本相同;缺陷容限门槛值明显低于长裂纹门槛值,采用长裂纹门槛值作为缺陷容限门槛值会导致偏于危险的结果;有限元法与Y.Murakami公式应力强度因子计算结果非常接近,Y.Murakami公式计算结果略低于有限元法。
Defect tolerance design method fully consider the characteristics of helicopters, the damage tolerance design cleverly applied in the design of helicopters, through the defect tolerance to ensure the critical components of the service safety. In this paper, we use the method of fatigue limit backstepping to test the thresholds of three types of defect tolerances. The thresholds of defect tolerances are calculated using the finite element method and the Y.Murakami formula respectively. The results show that the thresholds of three kinds of defect tolerances, including 265μm, 374μm and 480μm, The thresholds of defect tolerance are basically the same. The threshold of defect tolerance is obviously lower than the threshold value of long crack. Using the long crack threshold as the threshold value of defect tolerance leads to the result of partial danger. The finite element method and Y.Murakami Formulas stress intensity factor calculation results are very close, Y.Murakami formula results slightly lower than the finite element method.