What pitfalls using BS EN 1993-1-1 with US shapes and mat'l?

[dozer]

We're looking at bidding a job that the owner has specified BS EN 1993 for steel design even though the location is in Africa (go figure). We will be using US shapes and material. We use STAAD.Pro for our steel design and right away I noticed that you cannot specify yield strength. You have to specify steel grade (S235 to S460) and the program will plug in the yield strength. So for 50 ksi steel I guess we would tell STAAD it is S355.

We sprinkle some stainless steel members throughout our structure with a yield strength of 30 ksi. I see nothing that goes this low in the European steel grades. One work around would be to call it S235 and not go over a unity check of about 0.85. I haven't completely thought this throuhg yet. Anybody have a better idea?

What other things should I be looking out for? We haven't bought any of the BS EN 1993 codes yet so I'm kinda fumbling around in the dark. Yeah, yeah, I know, "Buy the codes!" but before we do I want to make sure mixing European codes with U.S. shapes is tenable.

 

[dhengr]

Why not design to IBC, AISC (U.S. codes) and with U.S. shapes since that’s what you are going to use. And, then just show that at the major, critical, locations and details you do comply with the Euro codes too. This might more or less be done in tabular form, with spread sheets or MathCad, or some such. Every member and every detail or condition is not going to be critical, so you are doing your analysis and design in familiar codes, and then just confirming some of the critical conditions as you see them. I wonder if someone at AISC, IBC or the Euro people might not have some sort of a comparative study on their shelves already.

 

[Debaser]

Dozer, the reason they're using the BS EN is probably because they're a Commonwealth country,so the standard is in English, but uses metric units.

I'm not a structural engineer, but I know that the 'Blue Book' is/was the bible for steel section properties. Below are a couple of links to it. (TATA was Corus was British Steel...).

http://csbluebook.steel-sci.org/Support/Entry.htm

http://www.tatasteelconstruction.com/en/design_guidance/the_blue_book

 

[dozer]

Thanks for the replies. I like your idea dhengr, but our client is a major EPC firm that I suspect will not be that flexible. Maybe I'll float it by them though.

 

[valleyboy]

Interesting! Have you been directed which countries version of the Eurocode National Annexe to use?

I believe staad has a comprehensive sections library which will allow you to model us sections - but I will check tomorrow!

There are a few other resources you could use before investing in EC3. Access steel is a good web site with lots of worked examples you can access for free after registration. There are also a number of Tata publications available free of charge on the www.

 

[hetgen]

dozer,
US shapes / sections are not common in Africa; check with your supplier before you proceed with detailed design.

 

[Guest262653]

Besides Part 1-1: General rules and rules for buildings, please check Part 1-4: General rules — Supplementary rules for stainless steels.
You'll find additional information regarding stainless steel grades.

 

[BigInch]

I designed structures using USA shapes for refineries to be built all around the world, mostly using Japanese shapes, but sometimes other national standards. The only thing that was ever done when making the substitutions was to select the shape with properties closest to the USA shapes. I said closest, meaning not even necessarily a shape with all parameters greater than the US shape. Some parameters were often of actually a slightly lesser value. It's not really even close to a three digit significant figure world out there.

"People will work for you with blood and sweat and tears if they work for what they believe in......" - Simon Sinek

 

[homostructural]

Eurocodes, especially for structural steel, are really easy to use!

This link contains a full list of free bibliography (design examples, case studies, design guides) for structural steel design according to Eurocodes! I am sure you will find it useful!

All about Eurocodes:

http://www.DesignToEurocodes.com