×
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

Kink Brace Out-of-Plane Buckling Stability

Kink Brace Out-of-Plane Buckling Stability

Kink Brace Out-of-Plane Buckling Stability

(OP)
For a kinked brace, the out-of-plane buckling stiffness is obviously less than if the member is straight. My question is: how much less?

Intuitively, it seems that it is even less than the KL/r using the length of the two segments added together. You are losing strong axis buckling resistance in the brace at the kink - but again, how much? I would think this stiffness would reduce rapidly as the angle of the kink grew.

Please see the attached sketch for a visual. Note that the brace is kinked to begin with (to clear mechanical equipment), not due to the load.

Any guidance would be appreciated...


-5^2 = -25 winky smile

http://www.eng-tips.com/supportus.cfm

RE: Kink Brace Out-of-Plane Buckling Stability

Is there a moment-connection across the intersection at the kink in the out-of-plane direction?

RE: Kink Brace Out-of-Plane Buckling Stability

I think I would treat the three diagonal members labeled "C" as individual members, like chord and web members of a scissor truss. The upper right corner "C" is like a vertical web in a truss, and because of the skew/kink there will be compression in this member.

Like JAE I am wondering if there is out-of-plane bracing at that intersection. Without it, my idea may not work.

RE: Kink Brace Out-of-Plane Buckling Stability

(OP)
JAE - yes, the main member (shown from top left to bottom right in my sketch) has a fully welded, mitered joint, as if the beam/brace just made a slight turn. The 3rd member is just to take the in-plane offset thrust introduced by the kink.

a2mfk - Yes, the upper right member will take compression - that's what it's there for. No, there is no out-of-plane bracing which is why the member is rotated so that the strong axis faces that way.

PS: The "C" on each member was just indicating that they are all in compression - understandably elementary for this forum.


-5^2 = -25 winky smile

http://www.eng-tips.com/supportus.cfm

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