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)