Failure analysis of a helical compression spring for a heavy vehicles suspension system

(in lingua inglese)

Corrosion pits were formed as a result of metal exposure to the environment atmosphere and collection of fluid at the small gap between bearing coil and the first active coil. Corrosion pits acted as local stress raiser that accelerated fatigue crack initiation and propagation. Contact stress analysis showed that stress singularities presented at the edges of the contact zone, and it was the severer shear stress at these locations that facilitated cycle slip and resulted in crack nucleation. This result interpreted the observation that fatigue initiated at the right hand side of the wear scar.