The World's First 3D-Printed Steel Bridge (popularmechanics.com) 40
An anonymous reader quotes a report from Popular Mechanics, written by Laura Rider: After four long years of planning, the world's first 3D-printed steel bridge debuted in Amsterdam last month. If it stands up to the elements, the bridge could be a blueprint for fixing our own structurally deficient infrastructure in the U.S. -- and we sorely need the help. Dutch Company MX3D built the almost 40-foot-long bridge for pedestrians and cyclists to cross the city's Oudezijds Achterburgwal canal. It relied on four robots, fit with welding torches, to 3D-print the structure. To do it, the machines laid out 10,000 pounds of steel, heated to 2,732 degrees Fahrenheit, in an intricate layering process. The result? An award-winning design, pushing the boundaries of what steel can do.
Designers first came up with the concept for the bridge in 2015, with the goal of making an exceptionally efficient structure. To do so, they had to emphasize two things: simplicity and safety. To monitor the efficiency of their design, scientists at Imperial College London engineered the bridge to be a "living laboratory." A team of structural engineers, computer scientists, and statisticians developed a system of over one dozen embedded sensors for the bridge, which send live data to the university for further analysis of the bridge's performance. They monitor the bridge's movement, vibration, temperature, strain (the change in shape and size of materials under applied forces), and displacement (the amount an object shifts in a specific direction) over time. From that data, scientists built a "digital twin" -- computer science parlance for an identical, virtual rendering -- of the bridge that gets more accurate over time. With machine learning, they can now look for trends that might suggest modifications are in order.
For this bridge, designers utilized two methods of 3D printing -- Direct Energy Deposit (DED) and Powder Bed Fusion (PBF). With DED, the printer feeds material (typically in powder or wire form) through a pen-like nozzle, and an intense heat source (typically a laser, but sometimes an electron beam) melts the metal on contact. PBF works similarly in that a laser or electron beam melts powder down to build each layer. The main advantage of PBF, though, is that it operates with much smaller (and more expensive) parts, resulting in a higher-resolution project than DED could accomplish on its own. This allows designers to take their visions a step further.
Designers first came up with the concept for the bridge in 2015, with the goal of making an exceptionally efficient structure. To do so, they had to emphasize two things: simplicity and safety. To monitor the efficiency of their design, scientists at Imperial College London engineered the bridge to be a "living laboratory." A team of structural engineers, computer scientists, and statisticians developed a system of over one dozen embedded sensors for the bridge, which send live data to the university for further analysis of the bridge's performance. They monitor the bridge's movement, vibration, temperature, strain (the change in shape and size of materials under applied forces), and displacement (the amount an object shifts in a specific direction) over time. From that data, scientists built a "digital twin" -- computer science parlance for an identical, virtual rendering -- of the bridge that gets more accurate over time. With machine learning, they can now look for trends that might suggest modifications are in order.
For this bridge, designers utilized two methods of 3D printing -- Direct Energy Deposit (DED) and Powder Bed Fusion (PBF). With DED, the printer feeds material (typically in powder or wire form) through a pen-like nozzle, and an intense heat source (typically a laser, but sometimes an electron beam) melts the metal on contact. PBF works similarly in that a laser or electron beam melts powder down to build each layer. The main advantage of PBF, though, is that it operates with much smaller (and more expensive) parts, resulting in a higher-resolution project than DED could accomplish on its own. This allows designers to take their visions a step further.
Re: Dear BeauHD: Show some restraint on topics (Score:2)
Re:Dear BeauHD: Show some restraint on topics (Score:4)
I think that would have been a worthwhile article... if there were a time-lapse video showing the bridge being made. Just showing it being moved and dropped into place is not all that interesting. I want to see the processes they describe in action to get a feel for how it all works.
Re:Dear BeauHD: Show some restraint on topics (Score:5, Informative)
There are several videos that show the printing and history of the bridge. Here are two.
https://www.youtube.com/watch?... [youtube.com]
https://www.youtube.com/watch?... [youtube.com]
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Thanks, this is great! I was also wondering, why it wasn't printed as one monolitic thing, it looks like they stopped short of printing some, but not all of the landing curves at the ends.
Also, reading the summary first, I was under the vague impression that the bridge was 3D printed into its final place, which would've been cool :-D Some support pilons initially printed then cut, once the print is complete
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That was more informative than the article. Thank you.
They don't show restraint on dupes (Score:2, Insightful)
Dicedot is not going to change since it's profitable, apparently much more so than the real, long departed, Slashdot.
Tiny (Score:1)
I watched that video in anticipation, expecting to see some Golden Gate II level bridge .. instead, man that thing was tiny. As disappointed as Trump's date. Seriously, could have gone to home depot, gotten a plank, nailed it down, and called it a day.
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If it's the bridge I read about earlier, it's full of things like strain testers, etc. and is basically a scale model so they can figure out whether this process can be used for larger bridges. But it is also a useful pedestrian bridge, so why waste it.
Steel cares a lot about tempering (Score:4, Insightful)
And carbon, and other things. It's obnoxiously hard to 3D print some plastics on a small extruder even with a heated bed and an enclosure. They claim less material use because they can print complex shapes, but how does strength vs. weight compare because basically the entire bridge is one big weld?
Re:Steel cares a lot about tempering (Score:5, Informative)
My friends in aerospace claim 3D printed steel is much stronger than steel made the conventional way. Reference: https://www.sciencemag.org/new... [sciencemag.org]
Re:Steel cares a lot about tempering (Score:4, Funny)
Your friend needs to read the part that says 'under certain conditions'.
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So? Everything has "certain conditions" attached to it. I am sure paper beats steel under certain conditions too. Anyway, 3D printing is good enough to build rocket engines and the whole rocket itself .. what does that tell you? https://www.relativityspace.co... [relativityspace.com] Also, regarding the bridge .. they did structural tests on that bridge for 2 years before installing it.
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No it's not false at all. Aerospace, which has the most stringent durability and strength requirements, is moving to 3D printing for everything from rocket engines to jet engine turbine blades. If you didn't know that, I suggest you educate yourself. I provided multiple references, not anecdotal information. Here is a reference regarding jet engine turbine blades: https://www.ge.com/news/report... [ge.com]
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Yes, printed in an enclosure, under very controlled conditions. And then likely tempered to reduce residual stress. My question is on printing an entire bridge that way; can you actually scale up those controlled conditions to that size?
It's similar to the USSR making titanium-hulled submarines. They apparently had crews working in spacesuits in an entire warehouse full of inert atmosphere [nationalinterest.org].
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Yes, printed in an enclosure,
under very controlled conditions.
And then likely tempered to reduce residual stress.
Of course.
My question is on printing an entire bridge that way;
can you actually scale up those controlled conditions to that size?
Apparently. That's the whole point.
It's similar to the USSR making titanium-hulled submarines. .
They apparently had crews working in spacesuits in an
entire warehouse full of inert atmosphere
Did you expect it to be done in somebody's garage?
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The steel “sponge” matricies are indeed much more structurally efficient than traditional machined parts.
I can see the model working sufficiently well for a pedestrian bridge, but I have a lot of trouble understanding how it would be reliable for a multi-lane vehicle bridge even with a digital twin.
It's for production not repair and this is why: (Score:3, Insightful)
It's a nifty concept demonstrator but economically rolling, fabbing, welding and bolting steel is fast, easy, and the structures are easily repaired using either standard or easily fabricated sections produced anywhere convenient with basic equipment (plasma cutters, subarc welding machines etc etc).
3D printing structural elements for new production is where that tech is headed, and like all such complex structures repair may cost more than replacement. For example being a single piece one may not simply remove defective sections fabbed from standard beam and sheet then replace them. Instead each repair section will require much more complex custom fabrication not practical onsite (at least for a very long time).
Its a great idea for its real purpose but clickbait had to throw in "infrastructure repair" to get views. We can already cheaply fab bridges of any size. The problem is paying for them at all, not needing exotic production techniques more expensive than rolling mills. Printing is not rolling or forging and if you don't know why that matters for structures and components, do some reading.
Re:It's for production not repair and this is why: (Score:5, Insightful)
Its a great idea for its real purpose
People forget that the real purpose of this bridge is to research into 3D printing as a production technique. There's a reason why some 30 companies, organisations and research institutions were involved in building this bridge, and only one of them was an architect.
The bridge is almost universally hated. The council has had to apologies that this bridge isn't accessible as the one it replaced, and many people are of the opinion it just doesn't at all fit its surroundings.
It's not a good bridge. It is however a good research project.
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*by humans*
While obviously no such robots are available today, a welding robot could easily repair such constructions in the future.
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Then we use duct tape, obviously, until such robots are available ;-)
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You sent in a team of 3D printing robots, or a human welder.
Seriously?
Cost effectiveness (Score:2)
There's absolutely no reason you can't 3D print something in modular, easily replaced sections that get assembled like a plastic model kit. But in this case they're studying the long-term degradation characteristics of something of a size that might make sense as a modular piece of a "real" structure.
If cost-effectiveness is your only concern, then sure, a simple rectilinear assembly of mass-produced I-beams is hands down the best option. But taking that as your only consideration you'd wear nothing but b
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"We can already cheaply fab bridges of any size" - well, sort of. I'm wondering if this concept can actually help with some of the bottlenecks of conventional building practices.
Consider: Overpass failed in Andover, MA quite a while ago. Since it was unexpected, it was added to the existing backlog of steel production - with the result that temporary bridging was in place for *over 10 years* while they waited for the steel beams necessary to replace it to be made.
10+ YEARS?? Damn, that's a long ass lead t
dear 3D printers (Score:2)
Can you make doing gaudi like architectures more common? it looks quite awesome
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No, Gaudi style is ugly. There is a reason it didn't really catch on much.
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Actually 3-D printed (Score:3, Interesting)
But the real progress will be when we 3D print in place. Not "on site" but actually in the final location the object or building is supposed to end up. This will do away with an enormous amount of expense and complexity. I doubt our corrupt governments will allow that any time soon (see also the enormous difficulty required to get certified for habitation literally any non traditionally built building) but a man can wish.
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> stronger structure since there are no worries about welds
It looks like one single weld and nothing else
From the Company, the best link (Score:3, Informative)
Re: Yay, questionable stability! (Score:3)
Yeah, is not like you could print an entire rocket, engine and all.
Oh wait. Relativityspace.com
Robotic controlled welds are stronger than the base material, when you're talking about structural steel.
Failures happen when the process is not tightly controlled.
My only concern with this bridge would be corrosion. The surface isn't going to be perfectly smooth, so it's going to need a very good paint job to stop the water that's going to pool in places from rusting it away.
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You know nothing about steel, so shut up and read this link, educate yourself fool: https://www.sciencemag.org/new... [sciencemag.org]
That's great (Score:2)
Writer needs help (Score:4, Informative)
Writer is metalworking-illiterate (Score:2)
That's why we get shit content though Slashdotters are capable of understanding at a professional level.
40' pedestrian bridge unknown lifetime (Score:2)