可靠性分析威布尔三参数估计方法比较分析

Comparative Study on Parameters Estimation Methods for Fatigue Life Distribution on Reliability

对可靠性分析中疲劳寿命Weibull分布的参数估计方法进行研究。在研究相关系数优化法的基础上,提出一种新的参数估计方法——割线优化法。在MATLAB的基础上改进了概率权重矩法,使此参数估计方法精度提高并使之更方便于工程计算。给出了计算Weibull三参数的MATLAB语言程序,并对这三种参数估计方法进行了分析比较。运用这些方法进行工程实例计算,计算结果表明割线优化法有较高的精度。通过实例计算确定了各方法工程应用上的差异及其适用范围,对工程人员选用合适参数估计方法起一定指导作用。

Three-parameter Weibull distribution is one of the most common and widely-used distribution in reliability theory,specially fatigue life estimation.The goal is by studying some methods for estimating parameters of Weibull distribution to illustrate the applicability of each method.By studying optimization method of correlation coefficient,a new method-optimization method by secant iteration is proposed.And the accuracy of probability weighted moments is improved by using MATLAB.Then the method is more convenient in engineering calculations.MATLAB program for three-parameter Weibull distribution is given and this three methods are compared to determine the applicability of each other.Then it will be a good direction for engineers to do an appropriate choice of parameter estimation methods.What is more,it is demonstrated that the new method-optimization method by secant iteration is accurate enough to be used in reliability analysis by using two examples.