Girder or Primary Beam? Nomenclature 2

[ilyas415]

Hi all!

I recently started a job at a structural engineering practice outside of Europe where English is not the first language.

Being from the UK, I am familiar with the terms "Primary Beams" and "Secondary Beams". However, in my new firm, the engineers like to use the terms "Girder" and "Beam" for these, respectively.
I think this is based on U.S. structural engineering culture?

I do a lot of work internationally, so I'm curious to know which terms are more common. Is it the US-based terms or the primary/secondary descriptions?

Thank you!

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Ilyas

 

[Agent666]

In NZ and Australia its primary/secondary beams. It always made more sense to me than girder and beam as it describes the load path hierarchy in a way.

 

[JAE]

Midwest USA - Girders support Beams, which are usually repetitive - or Joists instead of Beams.

The term joist is usually an open web "truss-type" prefabricated proprietary member.

 

[Lomarandil]

In my (limited) experience, joists can be open-web steel members, but repetitive timbers in a floor are also called joists.
But if a repetitive member is in a roof (or sometimes a wall) it's sometimes a purlin.

Bridges are typically:
"Girders" biggest member in the direction of the span (longitudinal)
"Floorbeams" are the next members running transverse to the bridge that support stringers and brace girders.
"Stringers" are smaller, repetitive longitudinal members between or outside the girders to make up the roadway width.

My experience internationally tells me that certain regions of the world (Commonwealth, most of Africa) default to European conventions and code methodology. Other regions -- the Americas, parts of Asia default to US standards. Also depends where the university professors come from or attend school.

----
just call me Lo.

 

[ilyas415]

Everyday it seems like I am hearing new words for these... today I heard a local consultant using "sub beams" instead of secondary beams.

Anyway, thanks a lot for your input guys!

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Ilyas

 

[BridgeSmith]

But if a repetitive member is in a roof (or sometimes a wall) it's sometimes a purlin.

My understanding is that purlins are horizontal members - perpendicular to king posts and king trusses, directly supporting the sheathing, so basically a horizontal 'stud'. Would that be accurate, or am I off in my understanding?

Your bridge terminology is spot on.



Rod Smith, P.E., The artist formerly known as HotRod10

 

[phamENG]

PEMBs refer to their roof members as purlins.

In historic timber construction, purlins run perpendicular to the trusses. Often in large structures (churches, etc.), the purlins will be widely spaced and support rafters. Several church roofs in this area are constructed with large trusses at 15-20' o/c, purlins at the eave (sometimes omitted in favor of bearing directly on the wall), 3rd points, and near the ridge. Then rafter span from wall/eave to the ridge - often with nothing more than a ridge board.

EDIT: I'm in the Mid-Atlantic region, US

 

[BridgeSmith]

Thanks for the info, phamENG. Good to know.

Rod Smith, P.E., The artist formerly known as HotRod10

 

[RPMG]

In the US, "Primary Structural Steel" is used in architectural codes for fireproofing, where "Primary" refers to columns, girders, and beams. It would be ambiguous to use the term in the US.

 

[STrctPono]

My understanding of hierarchy for framing members in buildings to be: Girder - Beam - Joist

Or for bridges: Girder - Beam - Stringer

 

[271828]

I've never quite understood why anybody would want to use more syllables.

Girder wins the syllable war over Primary Beam by two.

Beam kicks the crap out of Secondary Beam also.