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:

S_e=k_ak_bk_ck_dk_eS_e’

k_e=1/k_f

k_f=1+q(K_t-1)

Take K_t for combined bending & torsion (use K_t=2.5 for keyseats)