Fracture analysis of a camshaft made from nodular cast iron

The camshaft is a shaft having some semi-oval protrusions which are designed to control the open and close intervals of the inlet and exhaust poppet valves in the gasoline and diesel engines. Rotation of the cam which takes its movement from the crankshaft via a chain or a trigger belt causes its profile to slide against the smooth flat closed end of a cylindrical member known as a follower. In this study, fracture analysis of a camshaft of an automobile engine is carried out. The analyzed camshaft is fractured after a very short period of usage of the car. For the determination of the failure reason, the microstructure and chemical compositions of the camshaft material are determined. Some fractographic studies are carried out to asses the fracture conditions. A stress analysis is also carried out by the finite element technique for the determination of highly stressed regions on the camshaft.