EK435
Warping generally occurs when the cross-section is no longer planar (i.e. parts of the section do not remain in its original plane) during the plane’s displacement as the member twists.
EK433
The torsional resistance of a beam twisting about its longitudinal axis is usually divided into: uniform (St. Venant) torsion and non-uniform (warping) torsion.
EK221
The degree of warping that takes place depends on the shape of the section, and is most pronounced in thin walled channels.
EK219
Warping restraint increases the torsional stiffness of a member, and at any point along its length the applied torque is resisted by the two components, one due to the St. […]
EK218
If warping is prevented by rigid supports at the ends of the member, the torsional stiffness is increased and longitudinal tensile and compressive stresses are induced.
EK217
In general the cross-sections of members subject to torsion do not remain plane, but tend to warp. Warping is the change in geometric shape of the member so that cross-sections […]