Introduction to Elasticity/Torsion of thin walled open sections
Torsion of thin-walled Open Sections
Examples are I-beams, channel sections and turbine blades.
We assume that the length is much larger than the thickness , and that does not vary rapidly with change along the length axis .
Using the membrane analogy, we can neglect the curvature of the membrane in the direction, and the Poisson equation reduces to
which has the solution
where is the coordinate along the thickness direction.
The stress field is
Thus, the maximum shear stress is