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


Lightly loaded brace to column connection

Lightly loaded brace to column connection

Lightly loaded brace to column connection

The attached connection is for a lightly loaded brace framing into a column (circular tube). There is a 4" bent plate that is tied to the face of the column with U-bolts. The red line indicates where I see the workpoint for the brace. The intercept of the workpoint & column CL is about 11" below top of plate (you can deduce the relative geometry from that).

I see a couple things that bother me about the connection:
1. U-bolts
2. A double bent plate
3. A single bolt for the brace end connection
4. A large eccentricity from the workpoint to the bent plate center

Is this a "bad" connection? Or am I just so accustomed to seeing robust connections on industrial structures that something like this isn't as sensitive to the four points above?

The braces are mainly for stability for the top beams in the long direction and lateral stability in the short direction. I'm kind of withholding some info to focus on the above questions.

RE: Lightly loaded brace to column connection

Quote (skeletron)

Is this a "bad" connection?

Bad? Bloody horrible mechanically. That said, it surely does have some capacity and may well be the right solution for whatever your application is: light load, nominal stability, perhaps a functional need for being easily added or removed from an existing post without welding...

In my opinion, the capacity of this connection could not be accurately ascertained without physical testing. One might be able to come up with a reasonable lower bound capacity via calculation however.

RE: Lightly loaded brace to column connection

Ha! Okay, thanks for putting my gut feel at ease. I think the design is a response of chasing the problem's own tail, so I'm on the hunt for a different solution.

RE: Lightly loaded brace to column connection

There is no actual work-point that intercepts the column is there? Any particular reason you do not let the braces get closer to the column before you connect to them? If the picture is to scale, it looks like the braces will almost pass right behind the column.

As far as analysis, I agree with KootK, you would have to test it. Since both braces can act simultaneous or separate while also having one in compression and the other in tension, it gets even more complex. What would "mirroring" the brace do for you?

RE: Lightly loaded brace to column connection

Ron, you're correct. The work-point doesn't intercept the column...eccentricities gone wild. Not sure of why this detail was designed this way; I'm looking after the approval drawings and noticed this while flipping through. It's not my cup of tea and I think the designer might have been in the mindset of "keep the steel weight low to keep the cost down". I'm looking at a redesign where proper beam sections are used to reduce the need for the braces (they are knee braces).

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!


eBook - Efficient and Effective Production Support with 3D Printed Jigs and Fixtures
Jigs and fixtures offer manufacturers a reliable process for delivering accurate, high-quality outcomes, whether for a specific part or feature, or for consistency across multiples of parts. Although the methodologies and materials for producing jigs and fixtures have evolved beyond the conventional metal tooling of years past, their position as a manufacturing staple remains constant due to the benefits they offer. Download Now
Overcoming Cutting Tool Challenges in Aerospace Machining
Aerospace manufacturing has always been on the cutting edge, from materials to production techniques. However, these two aspects of aerospace machining can conflict, as manufacturers strive to maintain machining efficiency with new materials by using new methods and cutting tools. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close