ESDU 79032:1984

ESDU 79032 gives two graphs, one for the stress concentration due to tension or bending (which is accurate to within 5 per cent) and one for the stress concentration due to tension (which is accurate to within 10 per cent). The curves were derived theoretically and are functions of the groove geometry (width, depth and corner radius). They apply to hollow shafts provided the thickness exceeds ten times the groove depth. The position of maximum stress in each case is indicated and it is suggested that for combined loading an overestimate of stress will be obtained by assuming the maximum stresses due to the two loadings act at the same point. Design against the fatigue limit is discussed and two approaches suggested and illustrated in a worked example, one where the minimum radius is specified (and ESDU 74016 provides data for steel) and one where the radius is unspecified or very small, in which case the groove is treated as an initial defect in a fracture mechanics analysis.