Geometric stress concentration for a shaft with shoulder fillet in torsion

Geometric stress concentration factor Kt = A(r/d)^b for a stepped shaft with a shoulder fillet loaded in torsion, from chart-fit coefficients A, b keyed on the D/d ratio.

✓ validated against legacyoriginal: /calculators/e1_1a.htm

Dimension ratio, D/dDimension ratio, r/d

Geometric stress concentration, Kₜ1.37

Coefficient, A0.83425

Coefficient, b-0.21649

Method & references

Kt = A(r/d)^b for a shaft with a shoulder fillet in torsion.

The computation is a literal port of the original client-side JavaScript from /calculators/e1_1a.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.

Geometric stress concentration for a shaft with shoulder fillet in torsion — Engineering ABC