形状参数选值对细节疲劳额定强度的影响

Influence of Shape Parameters on Detail Fatigue Rating

针对细节疲劳额定强度(DFR)的威布尔分布统计理论所涉及的形状参数α选值问题,提出了基于随机数学的DFR-α模型。基于该模型,对比了选用波音许用α值与国产材料实测α值获得的DFR计算误差。结果表明:若直接使用波音α设计许用值,国产铝合金材料DFR计算相对误差在5%以内,国产钛合金DFR计算相对误差在10%以内;σb≤1700 MPa的国产钢,DFR计算相对误差在5%以内。

Aiming at the problem of shape parameter a selection involved in Weibull distribution statistical theory of detail fatigue rating(DFR),a DFR-αmodel based on stochastic mathematics is proposed.Based on the model,the calculation error of DFR is compared between the allowable value of Boeing and the measured value of domestic materials.The results show that the relative error of DFR calculation of domestic aluminum alloy material can be controlled within 5%,and that of domestic titanium alloy can be controlled within 10%.For domestic steel withσb≤1700 MPa,the relative error of DFR calculation can be controlled within 5%.