Convert ASCE to Eurocode Inputs

[TLHS]

Hey All,

Anyone have literature on how to convert ASCE wind and seismic inputs to approximate Eurocode equivalents? I'm trying to help a client that's having products engineered and manufactured in Europe for use in North America. The supplier has a set design methodology that is fit for purpose, but it's based on Eurocode. I really don't want to throw ASCE requirements at these guys that, from discussions, clearly wouldn't be working from a position of strength trying to plug a different code into their design process. I'd prefer if they could do their usual calcs and then maybe do an additional proof using US methods. But to do that, they need inputs that they can use that are reasonably comparable.

I'm reasonably comfortable that a comparable wind value can be developed for the specific type of equipment. Looking at the seismic design methodology it may not be feasible. The methodologies may diverge too much to line things up. Anyone spent enough time looking at both that can tell me whether it's worth spending my time on?

 

[milkshakelake]

I understand what you're trying to do. But in my own experience, when I had things fabricated across the pond, they used whatever codes we gave them. It was really tricky; we had steel manufactured in Japan and China that went through ASTM testing procedures. Had to fly in some people to overlook parts of it.

An alternative: instead of giving them wind and seismic inputs, you can give them the loading. The issue is that you'd be taking on the burden of much of the calculations yourself. But it depends on what is actually being manufactured. If it's some kind of industrial tank, for example, I don't see too much that can go wrong if you give them a conservative C&C wind load and a simple conservative rule to multiply the dead (and/or live) load by a percentage and apply it in the lateral direction. You'd need some basic knowledge of the Eurocode load combinations to see if you should give them strength or service level loads.

 

[TLHS]

Yeah, fabricated steel and things I'm 100% on board with. It's weird stuff where even if you gave them a north american code it doesn't explicitly tell you what to do for the type of things they're looking at that's the problem. Getting someone to do an explicit calc set for clear code compliance is one thing, getting them to understand the intent of, what's to them, a foreign code and then try to implement that into broad industrial standards is really tricky. Some of the consensus standards for the items are European anyway.

It's finding the balance of not trying to own the responsibility of the manufacturer on my side or my clients side but also knowing that if I just let them do what they want I'm going to be tearing them apart in document review. I'm likely going to have to handhold anyway to get them to hit an intent that I'm also comfortable with.

I agree that I might have to just do sample calculations for the equipment and figure out an area force for wind and a gravity multiplier for seismic that's conservative and get them to certify for that.

 

[milkshakelake]

One tricky point is special seismic considerations for particular types of equipment, so you have to know the equipment before giving them a Cs type of multiplier. I haven't done too many non-building seismic designs so I'm not sure what else to look out for, but I'm just bringing up a potential issue. The most basic thing that comes to mind is the risk category (i.e. II, III, IV). If you dive into the code more, there might be other things like that. Like if an equipment is a cantilevered column type of thing, which some heat exchangers look like, which would affect the R value.

 

[human909]

From my limited observations the Eurocode structural codes are some of the most robust and conservative codes out there. There are numerous academic papers on the topic too.

That said... Local requirements generally require a local certification. And there lies headache.

I work extensively with imported Eurocode items. Some are 'commodity' type structures where the they will cut every corner they can to win the sale.

On more than one occassion I've had to ask them to increase the strength of aspects as it has not been something I'm willing to certify.

If you can't get them to adhere to local codes maybe supply them with loading (wind/seismic) conditions that are 20% greater than you actually require...

 

[HTURKAK]

I have experience with EUROCODES and familiar with Northern America codes. I am not sure that i visualize your case if the subject is for structural steel or some equipment , process vessel and so waited to see the others' comments.
Can you give some more info?

My approach would be provide local data ( local seismicity , PGA , and basic wind pressure ) then check and validate their outputs as per NA codes.

My opinion..
..

He is like a man building a house, who dug deep and laid the foundation on the rock. And when the flood arose, the stream beat vehemently against that house, and could not shake it, for it was founded on the rock..

Luke 6:48