Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations KootK on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Searching For LTB Test Results for Beams With Moment Reversal & Intermediate Lateral Bracing 3

Status
Not open for further replies.

KootK

Structural
Oct 16, 2001
18,244
This is something of a desperate call to arms and is in relation to this thread: Rafter Without Fly Brace?.

As a result of that thread, it's come to light that LTB design procedures may not be quite as straight forward as they seem. We've been doing a lot of computational buckling analyses but we're running out of steam with that effort without having some physical test results to compare our work to.

What I seek is for someone to point me to any source of lateral torsional buckling test results for cases involving:

1) Moment reversal within the span and;

2) Bracing within the span that is lateral only in nature and, thus, provides no/marginal rotational restraint.

The sketch below shows an example although my request is by no means limited to that specific scenario. I'd happily adapt the computational work to suit whatever relevant testing we can dig up. I'm also happy to fork over some cash to get my hands on the information so suggestions need not be limited to freebie internet documents. The situation of interest is so very common in practice that I have to believe that there's something decent out there for testing. It may well just be so far in the past now that it's typewriter research work from 1932 buried in the Lehigh University library or something.

c01_gvq2f8.jpg


Consider playing chess with me on the Social Chess app at iTunes. Same handle. Fear not, I suck.
 
Replies continue below

Recommended for you

Don't know of any off hand, but I will be sitting down with my prof to nail down a Master's Thesis next month. If you don't find anything, maybe I'll take the idea and try it out...
 
I haven't been following that thread yet (too much work to go down that rabbit hole..) but have you considered using CTCIM's free LTBEAM software? It's my go-to tool whenever I have some doubts regarding elastic critical moments.

You can find it at the following link:
Link
 
I don't know if the lined articles fit your needs or not. But why not have a look. If you are AISC member, you can either get for free, or at a discount.

Link
 
Another potential verification tool being Idea Statica Member (beta only).

Link

 
I have just downloaded LTBeam.

I haven't tried it yet, but I note it includes a Validation.pdf document, which from a quick look includes comparisons with published experimental results.

Doug Jenkins
Interactive Design Services
 
LTBeam is used extensively to validate research work in Europe. I've found the following additional articles and an LTBeam version that also includes the effect of axial forces:

[URL unfurl="true"]https://www.cticm.com/logiciel/ltbeamn/[/url]
[URL unfurl="true"]https://www.researchgate.net/publication/333048538_Lateral_Torsional_Buckling_of_Steel_Beams_Elastically_Restrained_at_the_Support_Nodes[/url]
[URL unfurl="true"]https://www.researchgate.net/publication/313065404_Use_of_LTBeamN[/url]
 
How do you download LTBeam? It looks like theres a freeware version?

The website is in French, so it's a bit difficult to navigate
 
Next to the bottom of the page there's a button "Télécharger". It means "Download".
I think that you need to create an account first.
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor