×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Steel Tubing Beam Torsion Calculation
3

Steel Tubing Beam Torsion Calculation

Steel Tubing Beam Torsion Calculation

(OP)
How do you calculate the torsion stress in an open ended steel tube that has a torsional load applied? The tubing is 10mm wall x 125mm tall x 100mm wide and the 2500 lb load is applied perpendicular to the tube via a 1495mm long arm.

RE: Steel Tubing Beam Torsion Calculation

funnily 'nough there is just about nothing out there for the torsional stress on a thin walled open section, other than the maximum stress = 3*T/(b*t^2), where b is the length (perimeter) of the section.  

ok, you can fudge 'round with the "3" factor if your section isn't really "thin" ...

RE: Steel Tubing Beam Torsion Calculation

(OP)
Thank you for the reply.

Just for clarification for the maximum stress formula:

T = torque applied
b = perimeter of section
t = ?

Do you "fudge" the "3" factor up or down as the wall thickens?

I appreciate your help.

RE: Steel Tubing Beam Torsion Calculation

I don't think greenengr1's referring to an open cross section.  

Greenengr1, could you fill the tube with water if it had caps on the ends?

RE: Steel Tubing Beam Torsion Calculation

(OP)
The arm is attached to the tube with a pin through a welded clevis.

RE: Steel Tubing Beam Torsion Calculation

Roarke also has the equations. You should get a reasonable answer, your section size is not too thin.

Cheers

Greg Locock

SIG:Please see FAQ731-376: Eng-Tips.com Forum Policies for tips on how to make the best use of Eng-Tips.

RE: Steel Tubing Beam Torsion Calculation

Ref. Theory of Elasticity by Timoshenko and Goodier

For a closed shape such as a tube, the torsional shear stress is given by:

Tau = Mt/(2*A*t)

where tau is the shear stress

Mt is the torsional moment

A is the area enclosed by the centerline of the ring section of the tube

t is the thickness of the tube

The angle of twist per unit of length is:

theta = Mt*s/(4A^2*G*t)

where s = length of centerline of ring section of tube

G is shear modulus



 

Best regards,

BA

RE: Steel Tubing Beam Torsion Calculation

(OP)
Thanks all for helping this industrial engineer solve a mechanical problem.  The reference info is exactly what I needed.

Steve

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources