应用缺口件进行曲轴疲劳分析的可行性研究

Feasibility of crankshaft fatigue analysis using notched specimen

为了探索用标准缺口件替代实际曲轴进行疲劳分析的可行性,以某型号曲轴为研究对象,利用有限元方法分析了曲轴的受力状态。以此曲轴为基础,分别设计了适用于该曲轴的圆形缺口件和椭圆形缺口件,研究了二者的尺寸参数对应力分布和应力梯度分布的影响,提出了两种缺口件的优选设计方法,并完成了两种缺口件的优选设计,最后对椭圆形缺口件有限元计算结果和曲轴弯曲疲劳试验中圆角应力测试结果进行了对比分析。研究结果表明:椭圆形缺口件在应力状态、应力梯度两方面都比圆形缺口件具有更高的等效精度,其最大应力的有限元计算结果与曲轴弯曲疲劳试验结果的最大误差小于2.07%,从而验证了应用椭圆形缺口件进行曲轴疲劳分析的可行性。

The study was carried out aiming to explore the feasibility of replacing the actual crankshaft with a standard notched specimen for fatigue analysis. A type of crankshaft was taken as the research object and the stress state was analyzed using the finite element method. The circular and elliptical notched specimens were designed based on the crankshaft. The influence of size parameters towards the stress distribution and stress gradient distribution was investigated. Optimization design method was proposed,and the finite element calculation and crankshaft bending fatigue test results of elliptical notch specimen were also compared. The results show that the elliptical notched specimen has higher equivalent precision than the circular one both in stress state and stress gradient,and the maximum error between them is less than2. 07%,which verifies the feasibility of applying elliptical notch specimen to crankshaft fatigue analysis.