Determination of Shaft Diameters using Static & Fatigue Analyses
Static Analysis
Use the following D.E.T. equation:
Fatigue Analysis
¨ First identify all the critical locations where fatigue analyses would be necessary
¨ Critical locations are locations on the shaft where there is a combination of stress concentration with a high bending moment
¨ Stress concentration locations are those locations where abrupt changes in the cross-sectional area (case 1) occur or where there is a non-uniformity in the cross-section (case 2)
Use the following D.E.T. equation:
Se=kakbkckdkeSe’
ke=1/kf
kf=1+q(Kt-1)
Take Kt for combined bending & torsion (use Kt=2.5 for keyseats)