# Shaft torsional stress and twist
# Scope: Uniform solid circular shaft elastic twist.
# Status: illustrative worked example; engineering review pending.
# Inputs are example values. Checks are editable example requirements, not standards.

torque = 10 N*m
diameter = 15 mm
length = 300 mm
shearModulus = 79 GPa

polar := pi*diameter^4/32 [mm^4]
stress := torque*diameter/(2*polar) [MPa]
twist := torque*length/(shearModulus*polar) [rad]

check twist budget: twist <= 1 deg

scenario alternative: torque = 8 N*m