3rd TAGRA

Stress concentration is the local increase in stress caused by geometric discontinuities and is quantified by the theoretical stress concentration factor. In shafts, the change in diameter at the shoulder is a typical source of stress concentration and a common site of fatigue failure. Stress concentration factors for solid shouldered shafts are well documented, but data for hollow shafts are limited. In this study, the effect of the inner diameter on the stress concentration factor in shouldered shafts under axial tension was investigated by finite element analysis using ANSYS Workbench. Two-dimensional axisymmetric linear elastic analyses were performed. A matrix of 150 geometries was analyzed for D/d = 1.05-2.0, r/d = 0.025-0.3, and di/d = 0-0.8, where D and d are the larger and smaller shaft diameters, r is the fillet radius, and di is the inner diameter of the shaft. The model was validated against published data for solid shafts. The variation of the stress concentration factor with di/d and r/d was determined, and the results were compared with those for solid shafts. The results show that the stress concentration factor increases with increasing di/d, and the parametric data obtained in this study provide design charts for hollow shouldered shafts under axial tension.