Torsion of a tube of circular cross section with a transverse hole
s_Stress_Concentration_Factors/Holes/Torsion of a tube of circular cross section with a transverse hole.svg "Torsion_of_a_tube_of_circular_cross_section_with_a_transverse_hole")
Values for calculation
Calculation
Coefficient $ C_1 $
$$C_1=4$$
Coefficient $ C_2 $
$$C_2=-6.055+3.184\cdot\left(\cfrac{d_i}{D}\right)-3.461\cdot\left(\cfrac{d_i}{D}\right)^2$$
Coefficient $ C_3 $
$$C_3=32.764-30.121\cdot\left(\cfrac{d_i}{D}\right)+39.887\cdot\left(\cfrac{d_i}{D}\right)^2$$
Coefficient $ C_4 $
$$C_4=-38.33+51.542\cdot\sqrt{\cfrac{d_i}{D}}-27.483\cdot\left(\cfrac{d_i}{D}\right)$$
Stress concentration factor with the nominal stress based on gross area
$$K_{tg}=C_1+C_2\cdot\left(\cfrac{d}{D}\right)+C_3\cdot\left(\cfrac{d}{D}\right)^2+C_4\cdot\left(\cfrac{d}{D}\right)^3$$
Maximum normal stress
$$σ_{max}=\cfrac{K_{tg}\cdot16\cdot T\cdot 10^3\cdot D}{π\cdot\left(D^4-d_i^4\right)}$$