Fatigue life investigation of solid and hollow rollers under pure normal loading

摘要

Two solid and hollow cylindrical rollers in pure rolling contact subjected to pure normal loading have been modelled. Using a finite element package called ABAQUS, the stress and strain distributions in the two rollers in contact have been determined. The relative fatigue life of the hollow rollers compared to solid rollers has been investigated using the fatigue life model for rolling bearings developed by loannides and Harris. Different hollowness percentages have been studied: 20, 40. 60 and 80%. The hollowness percentage is the ratio of the diameter of the hole to the outer diameter of the cylinder. Both cases were studied — when the two rollers in contact are hollow and when only one of them is hollow while the other one is solid. Making the rollers hollow will result in redistribution of stresses over a larger volume in the contact zone due to the flexibility of the hollow rollers. That decreases the peak stress in the contact zone of the hollow cylinder when compared to the solid cylinder. Hollow cylinders have more flexibility when subjected to normal loading. And so, the stresses are redistributed so that the fatigue life is improved. The best stress redistribution and so fatigue life improvements have been found when both cylinders have around 60% hollowness.