Torsion

The twist or deformation of a body set up by a torque.

Torsion Theories

• Saint Venant torsion theory - basic torsion theory for which warping is not restrained
• Vlasov torsion theory - more general torsion theory for which warping can be restrained

Notation

The following notation is used throughout the torsion topic, unless noted otherwise:

• <tex>B</math> ... bimoment
• <tex>I_{\omega}</math> ... sectorial moment of inertia
• <tex>\phi</math> ... angle of rotation due to torsional moment
• <tex>\phi'</math> ... first derivative of <tex>\phi</math> with respect to the local X axis of the member
• <tex>\phi</math> ... second derivative of <tex>\phi</math> with respect to the local X axis of the member
• <tex>\phi</math> ... third derivative of <tex>\phi</math> with respect to the local X axis of the member

See Also

• shear flow

References

• AISC Design Guide 9: Torsional Analysis of Structural Steel Members (1996)
• Michael R. Lindeburg: Civil Engineering Reference Manual for the PE Exam, 9th Edition, 2003, p. 45-14 (eq. 45.54)