稀土球墨铸铁曲轴断裂的分析

运用线弹性断裂力学理论研究柴油机稀土球墨铸铁曲轴断裂强度和寿命问题。曲轴断裂的主要原因在于曲柄臂与连杆轴颈过渡圆角处存在缺陷，这个位置的缺陷在疲劳扩展达到临界状态时便导致曲轴失稳断裂。根据断裂力学理论和实验分析，提出了降低断裂率的一些途径。

Analysis on Fracture of Rare Earth Nodular Cast Iron Crank Shaft

The fracture strength and service life of the rare earth nodular cast iron crank shaft for diesel engine is researched based on the linear elastic fracture mechanics theory. The main reason of its fracture is that a defect exists at the transition fillet position of the crank arm and the connecting rod journal, where it will lead to a crank shaft buckling fracture after the fatigue reaches the critical condition. According to the fracture mechanics theory and tests, put forward some ways to reduce the fracture rate.