×
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

Composite box section weld requirements?

Composite box section weld requirements?

Composite box section weld requirements?

(OP)
I have a situation where I am cantilevering a 4' WF outrigger from the web of a WF to pick up some lighting.  It is a relatively small load, but the WF will not work with the torsion.  I have detailed this beam to have a single plate welded to the top and bottom flanges on the side opposite the outrigger for the entire length of the beam so that I can analyze it as an HSS with a wall thickness equal to the thinnest piece (plate, web, or flange).  
This section now works, but I am wondering how to calculate the required stitch welding for this detail.  I think that continuous welding at the top and bottom flange will add too much heat and cause problems, but I am not sure how to calc the required weld.  The shear flow from strong axis bending is straightforward, but what about the torsional stresses?

RE: Composite box section weld requirements?

There should be stress in all three directions on the welds - due to shear, bending and torsion produced by the outrigger. I would simplify the analysis by assuming the flanges resist the torsion, the added web plate takes the shear, and the box takes care of the bending, then check the welds required for the combined stresses.

RE: Composite box section weld requirements?

This exact calculation is done in Blodgett's book for a built up box beam, if you are willing to ignore the contribution of the web of your WF shape. I can give you the formulas if you don't have the book.

RE: Composite box section weld requirements?

(OP)
haynewp-
Are you referencing problem 5 on page 2.10-9?  If so, thanks for the letting me know of it.  If not, please tell me the formula.
Thanks.

RE: Composite box section weld requirements?

There is that one and also problem 10 on page 2.10-21.

RE: Composite box section weld requirements?

(OP)
That is an EXCELLENT example and discussion.
Thanks for pointing them out!!!

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