Geometric stress concentration for a shaft with a transverse hole in torsion
Geometric stress concentration factors for a shaft with a transverse (drilled) hole loaded in torsion — on the shaft surface at the hole (KtA) and below the surface inside the hole (KtB) — from independent polynomial fits in the hole/shaft diameter ratio d/D.
Geometric stress concentration, Kₜ,A (at surface)2.71
Geometric stress concentration, Kₜ,B (below surface)3.02
Method & references
- KtA: stress concentration factor on the surface of the shaft at the hole.
- KtB: stress concentration factor below the shaft surface, inside the hole.
The computation is a literal port of the original client-side JavaScript from /calculators/e1_2a.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.