金属材料旋转弯曲疲劳性能测量不确定度评定

Evaluation for calculating uncertainty for metallic material rotating bar bending fatigue properties

根据国家标准GB/T 4337—2015和GB/T 24176—2009,对给定应力下的疲劳寿命、给定寿命下的疲劳强度和S-N曲线这3种典型的疲劳性能的测量不确定度提出了初步的评定方法。评定方法包含A类评定方法(统计方法)和B类评定方法。以试验数据为例,针对给定应力下的疲劳寿命、给定寿命下的疲劳强度和S-N曲线分别展示了评定方法的应用,同时给出了S-N预测曲线和预测值的扩展不确定度示意图。

According to GB/T 4337—2015 and GB/T 24176—2009,there are three typical fatigue results used in uncertainty evaluation were provided. These are,i）fatigue life at a pre-determined stress,ii）fatigue strength at a pre-determined life and iii）the S-N curve. The evaluation methods employed are for type A（those which are evaluated by the statistical method）and type B. The application of evaluation methods were displayed by the example with testing data according to fatigue life at a pre-determined stress,fatigue strength at a pre-determined life and S-N curve. At the same time schematic figure for the expanded uncertainty for predicted life value was offered.