Optimum shape of a simply supported beam
Optimum shape of a simply supported beam
(OP)
http://in sider.alta irhyperwor ks.com/art icles/intu itive-tech nology-for aec?goback =%2Egde_99 408_member _110896633
figure 3 in particular.
This shape surprises me a little, any comments? I'd have expected a direct compression strut running down from the force application point to each support.
figure 3 in particular.
This shape surprises me a little, any comments? I'd have expected a direct compression strut running down from the force application point to each support.
Cheers
Greg Locock
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RE: Optimum shape of a simply supported beam
He dosn't specify optimization with respect to what: refers to strength and lightness, but what about stiffness, cost, aesthetics,etc. (the last being possibly what really he is caring about). And of course the result will depend on allowed materials, available equipment,etc.
Chatter, though the argument is quite serious, of course.
prex
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RE: Optimum shape of a simply supported beam
I wonder how one specifies for the program, it looks like big change in approach.
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Optimum shape of a simply supported beam
I get the impression he's using Figure 4 as a _bad_ example, where the optimizer went from a pierced sheet rib to a bit of lovely Zeppelin structure, without his diddling.
Or something like that; I couldn't bring myself to study his prose.
Mike Halloran
Pembroke Pines, FL, USA
RE: Optimum shape of a simply supported beam
While we'd expect to have a node at each support the offset of those sames nodes towards the center of the beam suggests some sort of balance of compressive behavior with tension behavior. In other words minimizing huge compressive regions in favor of introducing tension in smaller regions where SEs would overlook them as they are refinements without benefits to us on the whole.
It definitely reeks of organic structural development. Something that as a matter of evolution is great after possibly 2 million years of adaption to a possibly stable load and support but definitely not something I'd design for 20+ years subject to who knows what!
Regards,
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Qshake
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RE: Optimum shape of a simply supported beam
It would be interesting to learn what load combinations were considered in the optimization.
BA
RE: Optimum shape of a simply supported beam
Kinda looks like one of the sleezy cult leader actors on "Big Love" too. Can his opinion really be trusted?
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Optimum shape of a simply supported beam
http://3
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: Optimum shape of a simply supported beam
RE: Optimum shape of a simply supported beam
It severely lacks any logical engineering assessment. "It" is much more Architect than Engineer. His flaw is his "weight" on aesthetics is much much to high...haha... leaving for a structure that intuitively to an engineer is weaker than is should be...not to mention the construction of those elaborate curves.
One other thing. He uses "user friendly technology" referring to software that does all the work. ... Although technology is great, understanding it is equally important.
Cheers,
Fe (IronX32)
RE: Optimum shape of a simply supported beam
Fe (IronX32)
RE: Optimum shape of a simply supported beam
Then it slaps a surface around the remaining highly stressed bit and you have a structure.
You can get the same effect by hand with a bit of thought, I've done it with spaceframes where I started with all nodes connected, then reduce the diameter of the tubes that are understressed, and increased the diameter of those that are overstressed. What's interesting is when you have stiffness requirements and strength requirements.
Cheers
Greg Locock
New here? Try reading these, they might help FAQ731-376: Eng-Tips.com Forum Policies http://eng-tips.com/market.cfm?
RE: Optimum shape of a simply supported beam
RE: Optimum shape of a simply supported beam
Slaves labor?
No OSHA and minimum wage/maximum work week laws, no environmental worries, and pay for it all (by conquering somebody else) and grabbing their loot? 8<)
RE: Optimum shape of a simply supported beam
I believe it uses the stress plots and effectively "grays" out the less stressed areas depending on well, how far you move the slider.
"We shape our buildings, thereafter they shape us." -WSC
RE: Optimum shape of a simply supported beam
"This tent packs so lightly. It does have some drawbacks, though."
RE: Optimum shape of a simply supported beam
RE: Optimum shape of a simply supported beam
I guess I was referring to the fact that this seems kind of like the Architect is now trying to eliminate the engineer with software he does not totally understand. He likely understands that it reduces density etc. , but does he understand the underlying principles, likely not.
Also, I implied that there does not exist an index for aesthetics yet. This could be the subject of some research. By index I mean the index we use in the optimization procedure like Stiffness, Strength, Dexterity, Weight, Cost. Seems like they need one that defines "Good Looking"
One of the problems I have with the article is just that. What is their definition of "aesthetics"? They don't say.
Fe (IronX32)
RE: Optimum shape of a simply supported beam
re: The Romans.
Was actually just commenting on their arches and viaducts as a structural form that have, in some cases, 'stood' the test of time, if you'll pardon the pun. Not sure about there politics etc., though.
RE: Optimum shape of a simply supported beam
RE: Optimum shape of a simply supported beam
Right and when you try to connect all the members (nodes)... things get more complicated and expensive I would suspect and perhaps the elegance and logic and organics all get lost.