Descon does not do eccentric brace? 2

[Ben29]

Please see attached printout from my Descon calculation. Descon does not have the ability to analyze an eccentric brace connection? Is there a work-around for this? Thank you!

 

[Rabbit12]

Descon is still around? Did it get sold? Years ago I emailed the developer and he responded that he was having health problems and wasn't updating the software.

 

[JoshPlumSE]

Yes, Descon is still around. It's not owned by the same guy. He either retired or passed away. I can't remember who bought it from him. But, I know someone did. I'm sure there is someone on this forum that knows more.

Ben29 - Could you enter the force in the 2nd brace as zero?

 

[skeletron]

Page 22 (Section 4.1.2) of Design Guide 29 mentions this. AISC doesn't use the vertical cut method, which I believe is synonymous to your situation.

The beam would have to be designed for the full vertical shear force of the brace through its web. With the second brace removed, the gusset would also be losing the stabilization effect of the brace. Therefore I would verify by:

1. Is there enough weld length to transfer the horizontal component of the brace?
2. Does the beam have shear capacity to take the full vertical force? Add stiffener or web doubler
3. Check the out-of-plane stability of the brace. Will it buckle with the force? If so, you may need to add a stiffener on the flange of the beam at one end of the gusset.

 

[Ben29]

Josh - that is exactly what I did, I entered the 2nd brace force in as zero. But of course it left the gusset extra long, and I wasn't sure how best to modify that (or if I even should).

 

[Ben29]

Skeletron - thank you for this info! Very helpful. Do either of you know if there is a site dedicated to steel connection design engineers? I am new to this field.

 

[Agent666]

Back before fancy software, people used to check things by hand.

Perhaps it might help in a situation where you are trying to utilise a piece of software designed for task A to do task B without comprehending all the potential limitations in fudging inputs to try get an output that suits.

 

[271828]

If you don't have the brace on the left, then why is the plate so wide? It seems like there would just be a simple gusset plate at the right-hand brace only. The manual calcs for that case are pretty easy. In case you're interested in another program, RISAConnection calls that a knee brace. (Edited for grammar. Sheesh.)

 

[skeletron]

@Ben29: I don't know if there is a "steel connection design" forum or site. But here are some options to help yourself hike up the learning curve:

1. AISC. Get your company to get you on their membership (or get your own). Their design guides and research papers are worth the price of admission.

2. DOWCO and CISC. Both organizations offer in-depth courses for connections according to CSA S16

3. Partner up with a fabricator or detailer and try to extract as much knowledge as they are willing to shed on you. Unfortunately, I don't think you'll get the same attention online.


Connection design is still based on rational engineering principles (to paraphrase William Thornton). Regardless of what you are using for design, your output still relies on evaluating the load path and the behaviour of the joint.