40CrNi2Si2MoVA钢机械加工与喷丸试样旋转弯曲疲劳寿命的预测方法

为了预测机械加工及喷丸强化后40CrNi2Si2MoVA钢试样在室温下的旋转弯曲疲劳寿命,结合商用有限元软件ABAQUS和疲劳寿命分析软件FE-SAFE对不同数值计算方法的适用性及准确性进行比较,提出了喷丸强化40CrNi2Si2MoVA钢的寿命预测经验公式。结果表明:对于机械加工试样,选择"Brown-Miller"算法和表面残余应力用于计算可获得比较准确的预测结果;对于喷丸强化试样,高应力水平下也可选用"Brown-Miller"算法及表面残余应力,而低应力水平下则应改用"Stress-based Brown Miller"算法及最大残余应力。基于上述两种方法提出的经验公式:σmax=–64.378·lgN+1449.268,可改善40CrNi2Si2MoVA钢喷丸强化试样疲劳寿命预测的准确性。

Prediction method of rotating-bending fatigue life of 40CrNi2Si2MoVA steel specimens after machining and shot peening

In order to predict the rotating-bending fatigue life of 40CrNi2Si2MoVA steel specimens after machining and shot peening in room temperature, the applicability and accuracy of different numerical calculation methods were compared by combining the commercial finite element software ABAQUS with the fatigue life analysis software FE-SAFE, the empirical formula for predicting the life of 40CrNi2Si2MoVA steel strengthened by shot peening was presented. The results show that using "BrownMiller" algorithm and surface residual stress in FE-SAFE can obtain a relatively precise prediction result for machined specimens.And for shot peened specimens, this method also can be taken in high stress level. While the "stress-based Brown Miller" algorithm and maximum residual stress are more suitable for shot peened specimens in low stress level. The empirical formulaσmax = –64.378 ·lgN + 1449.268 proposed based on the two methods can enhance the accuracy of fatigue life prediction of 40CrNi2Si2MoVA steel shot peened specimens.