AISC Design Guide 9 Formulas for Graphs

[Sam83]

Hi, this is an old thread

Last yeat someone provided a link to an engineering journal having the solution to all the differential equations given n the AISC design guide Torsional Analysis of Structural Steel Members.
The link does not work anymore. Does anyone have this file:

http://www.aisc.org/assets/0/544/546/670/59ce12b7-6d14-4861-89bf-ae2b7d4a12bc.pdf

I've solved 2: Concented torsion at midspan fpr Pinned-pinned and fixed-fixed.

 

[ishvaaag]

The solutions are at this paper, starting p. 110

http://academic.csuohio.edu/duffy_s/AISC_DG_9_Torsion.pdf

If you refer to the detailed (or at least more detailed) process following the diff. eqs. it may be within Trahair's text, will try to look tomorrow.

 

[ishvaaag]

Well ... that's the design guide itself; it also had the same in "Torsional analyhsis of Steel Members".

I made once a port to Mathcad 2000 of the solutions for the cases, it being able to perform the derivations. If I ported well the thing it may then report the derivations or be brought to such thing by just changing the numerical setup for the evaluation to a symbolical one, what Mathcad also does, even if that may lead to unsightly statements of the solutions (I have seen such thing with the solution to problems that Southwell reduced to a pair of terms and Mathcad needed maybe 15 or 20 to express the same thing with no easy simplification in sight by -just- using the abilities of the program).

I may post it if of your interest.

 

[Sam83]

Hi ishvaaag

Thank you for responding. I actually had this design guide you posted, but thank you anyways. I appreciate it much.

I did the two problems I mentioned (like tow years ago), concentrated torsional moment at mid-span pinned-pinned and fixed-fixed, with the differential equation. Both were checked and i found the pinned-pinned condition in a book and it matched my answer. So don't worry about the text book.

The design guide you posted has the angle of twist. To get all other equations ones has to take the derivative 3 times. I need all the cases and I just wanted to save some time.


I am currently trying to develop a software. It started with a library of spread sheet I created. These sheets can actually design a lot of members, per AISC, AASHTO, etc.. specifications.
They are mainly matrix based. I few graduate teachers have been checking them and they have turned out to be very powerful. They can even generate influence line of indeterminate structures.
The beam set for bridges is complete based on the force method.

For the beam set, I just need torsion of I beams to be done.
Sheets currently use an approximation to analyze torsion.

Thanks again,

Have a great weekend

 

[WillisV]

You can get the paper from AISC here:

http://www.aisc.org/store/p-1068-technical-note-torsional-analysis-of-steel-sections.aspx

Free to members, $10 to nonmembers. Note that though I've seen several EJ papers posted on the forums lately - that is technically a violation of their copyright - but maybe somebody will still post it for you...

 

[RFreund]

WillsV - Does that paper give the solutions to all the end conditions and the derivatives?

I have also been looking for this.
I believe they are listed in Roraks text but I had started with DG9 and would like to complete my spreadsheats.

Thanks

EIT

 

[Sam83]

Hi WillisV

Thank you for the information, but I have that design guide.I got it when I took a graduate course. What I meant was the document that has the solution to the derivatives for all the cases. I've been informed that AISC sold the right t this document to someone or something similar.
I think I am just gonna have to do them. If anyone needs the cases I mentioned doing before, please just let me know and I'd gladly post them.

Thanks again

Sam

 

[ishvaaag]

TORSIONAL FUNCTIONS FOR CASES 1 TO 12
AISC TORSIONAL ANALYSIS OF STEEL MEMBERS

I have made Mathcad work the derivatives symbolically, come to the right of the arrow towards the right in the pdf file. I have used Fi as angle, and corresponding derivatives.

The first page is a printout of the Mathcad file doing the numerical work, and serves as a reminder of cases and input.

 

[ishvaaag]

The Mathcad 2000 Professional worksheet that evaluates the torsional functions numerically, zipped.

 

[dik]

This will make JAE a bit happier... an AISC errata...

 

[WillisV]

Sam83 - why don't you actually look at the link I posted - it is not the design guide - it is a paper about the design guide which provides all of the derivatives / equations you are looking for.

 

[Sam83]

ishvaaag
Thank you. I had gotten up to case 6 when I read your email. Thank you so much. You saved me a lot of time.

WillisV
Thank you very much for the link and my apologies for making comments before verifying. I did open the link but I must've just read the "Torsional-analysis-of-steel-sections" part. So, I am sorry about that.