Question

Explain in details Prandtl’s theory for torsion of solid section.

Answer 1

mation of the twisted bar, enforce the governing equations of the theory of elasticity and
from them derive simplified equations on a reduced set of variables. Due to the uniqueness
of solutions, we can be sure that the assumptions made and the solutions found are correct
for the torsion problem.
The assumptions about the deformation resulting from the applied torque M3 = T are:
• Each x3 = constant plane section rotates as a rigid body about the central axis,
although it is allowed to warp in the x3 direction
• The rotation angle of each section β is a linear function of x3, i.e. β(x3) = αx3, where
α is the constant rate of twist or angle of twist per unit length.