Fatigue Crack Growth in a Solid Circular Shaft Under Fully Reversed Rotating Bending

摘要

The axle of a load train failed after 5.37 × 10~6 cycles from its service. Macro-fractography showed clearly the fatigue fracture. The stress distribution in the shaft revealed that the maximum alternating stress was considerably less than the material modified fatigue limit obtained at 10~7 cycles from the S-N diagram. Micro-fractography reported from the metallurgical laboratory proved the existence of a surface flaw. Ultimately, fatigue crack growth simulation was performed based on the simple Paris-Erdogan model for estimating the fatigue life of the defective axle. The results showed that the actual life of the axle could be satisfactorily predicted by means of the Paris-Erdogan model.