Spline stress calculation.
External splines.

This program is based on published article “When Splines Need Stress Control” by Darle W. Dudley.
Stepan Lunin and Scott Burnett.
2006.

Metric. DIN. Click here.

Input data:
Pitch Diameter, in:
D
Bore Diameter of Shaft, in:
Dh
Root Diameter, in:
Dre
Radial Height of Tooth In Contact, in:
h
Effective Face Width, in:
Fe
Application Factor (Table II):
Ka
Load Distribution Factor (Table IV):
Km
Life Factor Limited by Fatigue (Table III):
Lf
Life Factor Limited by Wear, Flexible Splines (Table VI):
Lw
Number of Spline Teeth:
N
Chordal Tooth Thickness at Pitch Line, in (MIN):
tc

Torque, in-lb = 63,000 * HP / n:
T

Allowable Shear Stress (Table I):
Ss
Allowable Compressive Stress (Table V):
Sc
Allowable Tensile Stress (Table VII):
St

Output data:
Allowable shear stress in shaft,S_s2(PSI) :
S_s2=Ss*Lf/Ka
Shaft Stresses S_s1(PSI):
S_s1=16*T*Dre/(Pi*(Dre^4-Dh^4))
Margin of safety (needs to be > 0):
S_s2/S_s1-1

Allowable shear stress in Teeth,S_s2(PSI) :
S_s2=Ss*Lf/Ka
Shear Stresses in Teeth S_s3(PSI):
S_s3=4*T*Km/(D*N*Fe*tc)
Margin of safety (needs to be > 0):
S_s2/S_s3-1

Flexible Spline
Allowable Compressive stress in Teeth,S_s5(PSI) :
S_s5=Sc*Lw/Ka
Compressive Stresses in Teeth S_s4(PSI):
S_s4=2*T*Km/(D*N*Fe*h)
Margin of safety (needs to be > 0):
S_s5/S_s4-1

Fixed Spline
Allowable Compressive stress in Teeth,S_s6(PSI) :
S_s6=Sc*9*Lf/Ka
Compressive Stresses in Teeth S_s4(PSI):
S_s4=2*T*Km/(D*N*Fe*h)
Margin of safety (needs to be > 0):
S_s6/S_s4-1

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