P-S-N曲线测定的最大似然法

MAXIMUM LIKELIHOOD METHOD FOR MEASURING P-S-N CURVE

本文提出了一种测定P-S-N曲线的最大似然法。这种方法利用了三参数S-N曲线方程,并用最大似然法和矩法求参数的估计值。通过对光滑试件和缺口试件在轴向加载下疲劳试验数据的处理,说明了该方法的应用,并分析了该方法的精度。

More specimens and test time would be spent if P-S-N curve is measured by the traditional moment method. The maximum likelihood method for measuring P-S-N curve is presented in this paper. Joining with the moment method, it can be used to estimate the parameters of P-S-N curve by means of the equation of P-S-N cure with three parameters. For illustration, this method is applied to deal with the data of fatigue tests on notched specimens and smooth specimens subjected to axial loads. It was proved that if the maximum likelihood method is useed to measure P-S-N curve in order to replace the traditional moment method, the number of specimens and test time will be greatly decreased, and the differences between the P-S-N curves obtained by these two methods (the maximum likelihood method, the moment method) and test results are very small.