Failure analysis of roller neck at a cardboard production plant

In this paper corrosion-fatigue failure of a roller in a cardboard production plant has been analyzed. The failure occurred at the bearing neck of the roller. Mechanical and chemical properties of the roller are determined and the fracture surface is investigated. Forces applied on the roller is examined, stress calculations are carried out and fatigue safety factor is calculated. Stress analysis is also applied to roller and bearing neck by using Finite Element Method (FEM) and the results are compared with the calculated values. Because of very high safety factor, reasons for failure are investigated and effects of fatigue failure are determined. These effects are corrosion-fatigue, working conditions and notch effect. In conclusion precautions which have to be taken to prevent a similar failure is explained by using FEM.