服役时间对曲轴安全系数的影响研究

在对曲轴进行动态仿真及有限元计算得到保证曲轴安全使用时最小安全系数的基础之上,分别用全新、强化试验500、1000、2000和3000 h后的曲轴做弯曲疲劳模拟试验,测定曲轴的剩余安全系数,从安全系数的角度评价曲轴是否可以再制造。结果表明:随服役时间的增加,曲轴安全系数略有下降,但幅度不大,其值远在最小安全系数之上;曲轴在经历一个完整的"制造-使用-报废"生命周期后,其剩余疲劳强度足以支持其进行再制造,进而完成下一个生命周期。

Effect of Service Time on Safety Factor of Crankshaft

On the basis of minimal safety factor calculated by dynamic simulation and finite element analysis,the bend fatigue tests of five crankshafts which were a new crankshaft as well as were subjected to 500,1 000,2 000 and 3 000 hours hop-up tests respectively were performed,so as to evaluate whether the crankshaft can be remanufactured or not as viewed from safety factor.The results show that the safety factor of crankshaft decreases with the increase of the service time,but it does not decrease significantly and it is still much larger than the minimal safety factor.Furthermore,after a full life cycle,the residual fatigue strength of the crankshafts is enough to support the crankshaft to be remanufactured.