Steel Shop Drawings - Connection Calculations for Fabricator

[FoxSE14]

Hi All,

How many of you out there have performed connection calculations for a Steel Fabricator on a large structure(s)? On buildings where the EOR wants calculations for ALL connections within a multi-story steel building, have you utilized software? Spreadsheets? Old fashioned hand calculations? Can you share any lessons learned, or tips/tricks/best practices for those of us entering this niche?

I've performed hand calculations on smaller structures in the past and gotten by just fine, but our firm is starting to see requests for larger buildings. I intend to explore RISAConnection and maybe some other packages to see if my life can be made just a bit easier through the use of software packages. Curious to hear how others have tackled such requests.

 

[WARose]

I've typically taken care of it with spreadsheets I have. I've got one where I can check angle connections (with or without a cope) for shear and axial. Very handy. Moment connections I've typically done by hand. For pure shear loads, AISC has tables.

Can you share any lessons learned, or tips/tricks/best practices for those of us entering this niche?

The first one that comes to mind is: don't try to run the numbers for every one. For example, find a upper bound for certain connection types (i.e. say max shear mixed with max axial load for any W10 by whatever).....and run it as few times as necessary.

Of course, a good shop makes all the difference. If you get some joker where you are rejecting half of his drawings.....somebody will try to pin the delay on you.

 

[dik]

...and since the EoR wants calculations make sure that with your submission that you thank him for reviewing same. Just share the liability a little...

Dik

 

[Heldbaum]

I've performed hand calcs but recently I've purchased Idea Statica for steel connections. Still in the process of figuring the software out but I already did some calcs there and it works well. Additionally it is linked with Advance Steel which I use for steel shop drawings. And of course it's linked with Revit. I work in US and for structural analysis I use Robot Structural which I know it's not popular here whatsoever but it works well with all autodesk software, including Idea Statica. They have free 14-days trial version if you'd like to try it out.

 

[FoxSE14]

I have heard $10-15/ton for the connection designs before. Is there a ballpark number that others use to check their fee against? ($/connection, $/ton, something else)

 

[amec2004]

Connection design is tedious and repetitive work, it's more suitable for software process, not for human being.

Life is short and engineers should spend more time with family or playing golf.

A good software package can get one connection design done within 5 mins where 4 mins is the time for input data.

For the same connection if it's checked manually, engineer needs probably 5 hours or probably one day plus there is no guarantee of correctness when you get fainted after hours of repetitive work.


AISC Steel Connection Design Software

http://asp.civilbay.com/connect

 

[KootK]

Tables, tables, and more tables.

My first stab at this was a stadium and the tedium of it almost ended me. Thankfully I had an intern helping who got to leave in a few months to recover. Similar to WARose's comments, you really have to find a way to set it up so that you're not looking at each connection individually. Even with software that can be unbearable. An approach that I had some success with was this:

1) Get a stable relationship going with a fabricator so that you're doing similar connections in the same fashion from job to job for the routine stuff.

2) For a given, routine design situation, produce a clean "typcial" calc using MathCAD etc and use that to generate tabulated designs. Then include the calc and tables in your package and make "design" little more than picking canned solutions from your own tables. I always worried that a hard ass EOR would reject this approach but none ever did.

3) Wherever possible, set up tables for the individual limit states design checks that come up frequently. Basically the AISC manual on steroids. Then, when doing a custom design, reference those as much as possible rather than doing fresh calculations.

Ironically, I feel that software is actually a more appropriate tool for those who design connections rarely to intermittently. If it's not part of you regular practice, you'll be slow at it and software will help as long as you understand it. If you're designing gobs of connections often, you'll probably prefer the control and bulk design potential of using tables or your own tools. And software tends to mostly be good at handling typical connections, the same ones that you can tabulate fairly easily. Lastly, if you're not the EOR for the project, it may not make sense for you to try to model the whole building just to be able make use of software design en masse.


I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[KootK]

Good, recent thread on some of the software options: Link

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.