Eccentric Load- Torsion
Eccentric Load- Torsion
(OP)
Theoretical question....
If you had a wide flange beam, simple span, torisally restrained at supports.
You have a point load at the center of the beam span, but the load is eccentric to the center line of the beam (not thru the shear center)
This will obviously cause torsion on the beam, but is there a way to accurately calculate the web bending due to the eccentric load.
In other words, the bending moment on the web is not simply P*e, correct?
We are talking about a matter of relative stiffness, are we not?
If you had a wide flange beam, simple span, torisally restrained at supports.
You have a point load at the center of the beam span, but the load is eccentric to the center line of the beam (not thru the shear center)
This will obviously cause torsion on the beam, but is there a way to accurately calculate the web bending due to the eccentric load.
In other words, the bending moment on the web is not simply P*e, correct?
We are talking about a matter of relative stiffness, are we not?






RE: Eccentric Load- Torsion
A minor amount of the torsion will be resisted by rotational stiffness of the beam. Tr / G J = rotation.
Given all of the factors, this drops into a diff eq in order to determine the sharing between warping and rotation:
Ttot = GJ dr/dz - E Cw d3r/dz3
RE: Eccentric Load- Torsion
This is available from the AISC website free to members or for a fee.
Jim