How does a portal frame work?
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- čas přidán 5. 08. 2021
- In the UK most large warehouses and industrial buildings are made using steel portal frames. In this video, a structural engineer shows how portal frame buildings work. In this demonstration you will see how the bending moments, stability and wind bracing work.
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Software used in this video: geni.us/sketchup - Věda a technologie
Not gonna lie i found poortal frames very simple and easy... yet I have spent days jus staring at my computer thinking what to do. Long story short this video is a great way to learn something so simple and to understand it so easily.
Very clear information... thanks
Thanks for sharing!
Hope to see concept design more in steel design.
Thanks Robin. Great video. Also do you mind telling me how you present this without the toolbars?
Great video, thanks Robin. What software are you using here for this sketch/model?
SketchUp.
Is seismic action not required to be analysed in UK? I would use X bracing instead of Z bracing, furthermore, I would also brace the middle bay that will significantly improve the stability of the whole building.
Interesting insight.
I always love your videos they informative ...
I have a few questions though
1) a Cable , Bracing rod and Rolled Steel Angle which one do u think is best to use for your Wind bracing
2)I didn't seen any bracing in the middle of the structure may I ask why ?
Hi Michael. RSA would be more usual for side bracing, CHS for roof bracing.. No need in middle of bays because the eaves tie transfers the wind load to the end bays.
@@RobindeJongh Thank you Sir
Great video. If you could answer to some of my queries, it would be of great help. Should the plan bracings and vertical bracings be in the same bay? If there are no gable columns, how the plan and vertical bracing is done? Can we provide eaves beam in place of vertical bracings? Thanks.
Just to clarify, that end bay is portalised but the windposts will have slotted connections at the top? Otherwise you will need bracing in those last gable bays?
Correct - either portalised end bay with slotted connections for the wind-posts, or braced with simply supported rafters.
Hi Robin, Would a portal frame roof section work on a 18" brick built warehouse direct off the brickwork with no legs? (20 metre span). Thanks Malcolm
Hi. No, that would not have any lateral resistance and would probably be dangerous.
if u make the column base rigid, will it be required the vertical bracing or not?
You'd need a very large base!
How do you know the bases act like pins connections?
The design philosophy of a portal frame is usually that the bases act as pinned.
@@RobindeJongh also to make the analysis easier and to reduce cost , since pin connected are cheaper than moment connections right?
@@michaelacheampong2869 A moment connection at the base would lead to an enormous pad base, making it uneconomical.
what about buckling in the middle column even they have not braced
I haven't shown the cold rolled members on this model (purlins and side rails), just the main members.
@@RobindeJongh thank u a lot
Why did you not put brazing on the end gables ...as this is a pin framed --wouldn't it just fall over like a pack of cards ....seems unstable to me ?
Bracing**
Correct - the end gable would have some bracing usually. Often the end bay is a portal frame same as the other bays if it's deemed cheaper to manufacture.
I'd say gable end wall bracing would be beneficial but not critical. Of course it totally depends on the design but transversal sway is resisted by moment connections at eaves and apex i.e.haunches plus more often than others there will be dado walls all around the perimeter which stffen the structure. Having said that if it is indeed designed as simply supporting and not moment resistant portal(just the gable end) wall bracing would be the way to go. One of the other comments was related to the size of the footings. I think you showed it adequatly as in rectangular pads with the longer side aligned with the portalisation. And of course just like you said Robin , this is showing the core thinking not the full works. So for instance those pads most likely will be connected by a 600mm wide trenchfill footing under the dado walls and all of the footings would probably have a tr34 industrial slab to further stiffen the structure. As for anything light gauge / metsec I'd look at that as a seond stage which is why I probably wouldn't have bothered to include in a brief video that focuses on the primary structure. Keep them coming Robin.
Hello and greetings. I would like to thank you for recording such videos, which help people like me a lot. I have a request from you. My request is that you help me to build the halls I want. My hall has an opening of 30 meters, but without the middle column at a height of 6 meters. I want to know with what size H beam I can build these halls. I will build it. Of course, if the opening is 30 meters, it will answer. If it doesn't answer, I can make the opening of the shed up to 23 meters. I am waiting for your correct answer. I thank you again for your help. I wish you a good day.
Cara nya dan bahan bahan
Apa bisa api ari angin udara adart dan lain lain saya buat ter gantung surag saya buta portal surga 👍
Can you write what you talk in english then i copy it and tanslat to arbic becouse i need this information now
I went translation it in Arabic plz