Torsion members with noncircular cross sections tend to warp when subjected to torsional
loads. However, if a torsion member is fully restrained by a heavy support at one end,
warping at the end section is prevented. Hence, for a torsion member with a noncircular
cross section, a normal stress distribution that prevents warping occurs at the restrained
end. In addition, a shear stress distribution is developed at the restrained end to balance the
torsional load.