缺口件疲劳寿命分布的敏度分析

就缺口件疲劳寿命分布对材料属性、载荷和几何三种不确定性设计变量分布的敏度进行了分析。首先选取疲劳有效应力作为疲劳损伤参量,应用基于随机有限元方法的缺口件疲劳寿命分布计算模型,分别计算了三种不确定性设计变量分布的变化带来的疲劳寿命分布的变化。然后运用设计变量为随机变量时的敏度分析方法进行分析,结果表明它们对缺口件寿命分布影响程度的大小顺序依次为载荷、几何和材料属性,并且缺口件寿命分布对它们的敏度大小在同一量级上。

Sensitivity Analysis of Fatigue Life Distribution of Notched Specimen

A sensitivity analysis for fatigue life distribution of notched specimens with regard to distribution of three design variables with uncertainty (material property, load and geometry) is carried out in this paper. Firstly, by selecting fatigue effective stress as the damage parameter and applying computational model for fatigue life distribution of notched specimen based on stochastic finite element, corresponding variation of fatigue life distribution caused by variation of distribution of each of the three design variables was calculated. Then, making use of the sensitivity analysis method suitable for random design variables, a sensitivity analysis was conducted. The result shows that the load has the largest influence on the fatigue life distribution of notched specimens, then the geometry, lastly the material property. However, the values of sensitivity of these three factors are at the same magnitude.