Not logged inAmerican Welding Society Forum
Forum AWS Website Help Search Login
Up Topic Welding Industry / Technical Discussions / FEA Weld Classification
- - By TimGary (****) Date 12-18-2014 18:10
I've been asked a question that I don't have an answer for:

"We’re having some FEA work done on a project and the company that is performing it is asking about our weld callout. The note on the print calls out for G pulse unless otherwise noted which I told him that is our notation for pulse welding. The question then arose what type of weld classification we require, a Class W or a higher class like F or F2. "

Can anyone share with me the meaning of these classification?

Thanks,
Tim Gary
Parent - - By welderbrent (*****) Date 12-18-2014 18:52
Okay Tim,

You've really got me with this one.  But I need to ask some questions:

1) What is FEA?

2) Where is this job going, state wise?

3) After going through B21., D1.1, Google, and IBC, are they maybe asking about- 'W'= wind loads, or 'F'= earthquake seismic zone?  F can also be associated with fluid pressures including from flooding? 

Now there may be others who will instantly recognize these as representative of something I am not familiar with, but this is where my research has taken me thus far.

He Is In Control, Have a Great Day,  Brent
Parent - - By TimGary (****) Date 12-18-2014 19:14
Good questions Brent.
FEA = Finite Element Analysis, or an engineering design analysis for pre-determining acceptable weld joint designs to meet forecasted load requirements.
I doubt these classifications are AWS code related, maybe some type of typical FEA class or an internal designation?
The job is for weldments on heavy equpment to be used world wide.

Thanks,
Tim
Parent - - By welderbrent (*****) Date 12-18-2014 19:26
That was one that popped up in my Google search but I cast aside thinking it wouldn't be applicable.

Equipment, even with worldwide distribution shouldn't be looking to seismic or wind loads. 

They must have a classification for strength and/or finish quality having to do with distributed stresses so cracks won't start at corners with stress risers.  Ran into that when I did log stackers for LeTourneau in OR.  Had to have really smooth transition at all connections.  We used radiused gussets and not just square or triangular to assist with that.

Anyway, that info helps Tim.  I'll see what I can find and hopefully someone else will see this who has dealt with it directly.

He Is In Control, Have a Great Day, Merry Christmas and a Happy New Year,  Brent
Parent - - By TimGary (****) Date 12-18-2014 20:38
Thanks John.
Found this for F2,,,
Parent - - By 803056 (*****) Date 12-18-2014 22:31
What welding standard are you taking that information from?

D1.1 includes S-N curves, but the vertical and horizontal axis are logarithmic, not linear as indicated by the S-N curves you show.

AWS D1.1 assigns different stress categories for different geometry and weld details.

You would have to be specific about what welding standard or design standard is being used.

Best regards - Al
Parent - - By TimGary (****) Date 12-19-2014 15:34
Thanks for the replies Guys.

The standard we're working to is AWS D14.3- Specification for Eathmoving Construction and Agricultural Equipment.
The info I posted was supplied by the guy who asked me the question, after he asked for further explanation from the Customer who asked for the classification.
I'm not sure where the chart originated from.
I'm not familiar enough with the process to go into detail, but am looking forward to receiving training in it from a new FEA process under development from a company called EMC2, later 2015.
Looks like I've a lot to learn.

Thanks again,
Tim
Parent - - By welderbrent (*****) Date 12-19-2014 15:47
UUMM, I've heard that company name somewhere...have to look it up and see how I know them. 

Thanks for that.  Nice to know we were headed the right direction.

Brent
Parent - - By kcd616 (***) Date 12-21-2014 10:51
Brent
emc2
many people, and companies use it
e=mc2
hope that helps
sincerely
Kent
Parent - - By welderbrent (*****) Date 12-21-2014 15:00
LOL, yeah, I am familiar with Einstein's formula Kent.

But, I seem to remember a company name using the formula symbol.  Just can't remember under what context, company type, where, etc.

Brent
Parent - - By TimGary (****) Date 12-23-2014 15:38
EMC2, Engineering Mechanics Corporation of Columbus, Oh is developing a user-friendly version of their weld analysis software called Virtual Fabrication Technology™ (VFT) that is available for use without having to purchase any expensive licenses; i.e. you pay for it if and when you use it.
Evidently it's a web based program using Ohio State's super computers.
I'm scheduled to learn how to use it this spring, once they finish development.
Looking forward to it.
Might be an opportunity for others as well.

http://www.emc-sq.com/

Tim
Parent - - By ssbn727 (*****) Date 12-23-2014 17:56 Edited 12-24-2014 00:45
They use a lot of really good FEA commercial software like ABAQUAS, ANSYS, SYSWELD (I have this one), QWELD from the Edison Welding Institute besides VFT which was co-developed along with Caterpillar back in the Nineties and the fact that all of these and probably more that weren't mentioned are being synched together to work together as one is very impressive indeed. And the use of QWELD is another bonus as it does give a rapid solution to make quick distortion solutions along with SYSWELD which is made by a French company which is primarily used for automotive solutions as well as similar capabilities which QWELD has also makes the choice of combining these well proven existing packages to work together as one is exciting to anyone familiar with each of these single FEA applications... Sandia Labs has already evaluated this and they were impressed also...

Great stuff! I'm going to look into this further because I may just want to take the course also... Thanks for posting Tim! And Merry Christmas to you and your family along with everyone else in here too!:yell::lol::yell::lol::yell::grin::smile::wink::cool:

Respectfully,
Henry
Parent - By TimGary (****) Date 12-23-2014 20:17
Merry Christams Henry and all.
Wishing you a safe and healthy 2015.

Tim Gary
Parent - By welderbrent (*****) Date 12-19-2014 00:25
I wonder if anything like that is in the D14 codes for equipment?  Don't have them with me.  Will see what I can find.

Looks like a modification of the S-N curves that Al mentions specific for differing equipment usage and the stresses and cycles it would be subjected to.  Again, reminds me of the stresses of the log stacker moving across a pot holed log yard with 40-60 tons of logs raised up 15 ' in the air while travelling at 20 miles an hour.  The stresses there may be in the F2 category while a lawn tractor mowing the front yard would be in the W category. 

Interesting anyway.  Thanks for the OP question and additional information. 

Brent
Parent - By kcd616 (***) Date 12-19-2014 01:31
I like this
and surprise I disagree:eek::evil::twisted:
I would need to see this with my own eyes
I think someone is cherry picking #
and not you Tim
just imho
sincerely,
Kent
Parent - - By Tyrone (***) Date 12-19-2014 12:02
Hi Tim,
The FEA software needs the S-N curve to model in the behavior of the material.   It gets dicey if it's in the HAZ since those curves are not readily available.

We don't use classifications here.  If you give them the information that satisfies a classification, that should be enough:
1) geometry
2) load condition
3) crack details
4) S-N curve(s)

I'm off until the new year so won't be able to follow up until then.
Good luck
Tyrone
Parent - - By ssbn727 (*****) Date 12-20-2014 21:46
Just out of curiosity Tyrone,

What software application(s) are you using because when I "Play" my applications, the same information is required and like with your system, my software doesn't work by the use of specific weld classification per se like a F-2 or an F or a D and depending on the location of the joint within the structure in some cases other information needs to be added into the calculus also or else your models will not work properly... Here's an interesting article for Tim that was written many moons ago and published in the April of 1999 issue of the The Welding Journal:

http://www.aws.org/wj/supplement/Weaver/ARTICLE2.pdf

I use S-FRAME, or SAP2000 and refine with StressCheck... I want to start messing with this 30 day free trial from AutoDesk: Robot Structural Analysis Professional and find out what this doohickey can do! I got a friend that sending me some more software from AutoDesk that does FEA so when I find out more about it I'll let you and Tim know more about it also... Here's a link to the free trial offer from AutoDesk but, I must caution that this software will only work with 64 bit desktops:

http://www.autodesk.com/products/robot-structural-analysis/free-trial

I also want to check out SIEMANS Femap which I think has tremendous potential with all that it has to offer and is made by the same folks who came up with Solid Edge that's one of my favorite CAD applications:

http://www.plm.automation.siemens.com/en_us/products/femap/index.shtml

Here's a free trial of Femap also:

http://www.plm.automation.siemens.com/en_us/products/femap/free-femap.shtml#lightview-close

Respectfully,
Henry
Parent - By kcd616 (***) Date 12-21-2014 10:46
Henry,
omg
I subcontracted for siemens
great company
might check that out
sincerely,
Kent
Parent - By Tyrone (***) Date 01-06-2015 11:35
Hi Henry,
Hope you had a wonderful Christmas and happy new year.

We use different software, depending on the type of analysis (ex. transient, dynamic, linear).  I assume that you are interested in static linear analysis.  For that, we use Ansys and NX Advanced Simulation.

We had done comparative studies with the FEA "Lite" software that come bundled the CAD packages (ie UG NX and Pro E).  The limitations of the lite software can lead to incorrect outputs.  This could cause the Engineer to think their design is good, when it really isn't. Garbage in.....garbage out.  The trick is knowing the limitations.

Tyrone
Up Topic Welding Industry / Technical Discussions / FEA Weld Classification

Powered by mwForum 2.29.2 © 1999-2013 Markus Wichitill