6 ms·

I agree, but the bridge design appears to be extremelly robust (i.e., extraordinarily oversized) and it will be subjected to foot traffic, which has a negligibl

I agree, but the bridge design appears to be extremelly robust (i.e., extraordinarily oversized) and it will be subjected to foot traffic, which has a negligible service load. It's a pretty sculpture that people can walk on. That's it.

DrNuke 8y ago
Robust aka oversized does not counter brittle fracture, though, which is the main concern with 3D-printed artifacts. It depends on the material / the alloy but also on the technological process we generally call printing.
- Robotbeat 8y ago
  It actually does, since it reduces the local stress. Risk of fracture due to defects and repetitive loading is dramatically reduced (by order of magnitude or more) by increasing the material margins. It's a short foot bridge, so it's pretty easy to design it with significant enough margin. That said, it's not a very good idea nor a scalable solution to, like, anything. More like an art project.
  - DrNuke 8y ago
    Yes, you are basically saying that this particular artifact is just like a bridge-shaped pancake made of polystyrene and hosting very few ants at any given time. Which is actually an art project.
    - Robotbeat 8y ago
      I think that's overstating it. This bridge is plenty strong, just very inefficient and expensive.
  - geezerjay 8y ago
    > Risk of fracture due to defects and repetitive loading is dramatically reduced In this case I believe the design is due to concerns regarding the additive manufacturing process, which is prone to introduce a lot more defects than standard steel sections, and ina way that are hard to spot and to track.
dsfyu404ed 8y ago
>It's a pretty sculpture that people can walk on. That's it. Famous last words. https://www.miamiherald.com/news/local/community/miami-dade/article212571434.html https://www.miamiherald.com/news/local/community/miami-dade/... Bridges are supposed to be boring and functional. Fluffing them up with all sorts of over engineering to make them pretty tends to introduce unnecessary variables that are less well understood or less easy to account for or may be "unknown unknowns" which have the potential to reduce the strength of the structure. https://www.nytimes.com/2018/08/14/world/europe/italy-genoa-bridge-collapse.html https://www.nytimes.com/2018/08/14/world/europe/italy-genoa-... If you want to make a pretty art piece then make a fancy ornate bridge deck and slap it on top of your boring but functional steel I-beams that reliably carry rail, road and foot traffic worldwide.

DrNuke 8y ago

Robust aka oversized does not counter brittle fracture, though, which is the main concern with 3D-printed artifacts. It depends on the material / the alloy but also on the technological process we generally call printing.

Robotbeat 8y ago
It actually does, since it reduces the local stress. Risk of fracture due to defects and repetitive loading is dramatically reduced (by order of magnitude or more) by increasing the material margins. It's a short foot bridge, so it's pretty easy to design it with significant enough margin. That said, it's not a very good idea nor a scalable solution to, like, anything. More like an art project.
- DrNuke 8y ago
  Yes, you are basically saying that this particular artifact is just like a bridge-shaped pancake made of polystyrene and hosting very few ants at any given time. Which is actually an art project.
  - Robotbeat 8y ago
    I think that's overstating it. This bridge is plenty strong, just very inefficient and expensive.
- geezerjay 8y ago
  > Risk of fracture due to defects and repetitive loading is dramatically reduced In this case I believe the design is due to concerns regarding the additive manufacturing process, which is prone to introduce a lot more defects than standard steel sections, and ina way that are hard to spot and to track.

dsfyu404ed 8y ago

>It's a pretty sculpture that people can walk on. That's it. Famous last words. https://www.miamiherald.com/news/local/community/miami-dade/article212571434.html https://www.miamiherald.com/news/local/community/miami-dade/... Bridges are supposed to be boring and functional. Fluffing them up with all sorts of over engineering to make them pretty tends to introduce unnecessary variables that are less well understood or less easy to account for or may be "unknown unknowns" which have the potential to reduce the strength of the structure. https://www.nytimes.com/2018/08/14/world/europe/italy-genoa-bridge-collapse.html https://www.nytimes.com/2018/08/14/world/europe/italy-genoa-... If you want to make a pretty art piece then make a fancy ornate bridge deck and slap it on top of your boring but functional steel I-beams that reliably carry rail, road and foot traffic worldwide.