7 ms·

Lobster shell patterns make concrete stronger

88 points by quotha 6y ago

andrewl 6y ago
Biomimicry is fascinating. There's some good info at the Biomimicry Institute: https://biomimicry.org https://biomimicry.org
sradman 6y ago
The news release Bio-inspired: How lobsters can help make stronger 3D printed concrete [1] from RMIT University (with 1 minute video) and the paper Influences of Printing Pattern on Mechanical Performance of Three-Dimensional-Printed Fiber-Reinforced Concrete [2]: > Underperformed interfacial bond and anisotropic properties are often observed in three-dimensional-printed concrete, where the printing pattern is unidirectional. Such issues could be potentially alleviated by replicating microstructures of natural materials or applying different architectures, where printed layers are arranged into unique and unconventional patterns. > The addition of steel fibers leads to noticeable improvement on both compressive and flexural strengths of samples in any pattern compared with their counterparts without fibers. Besides, the inclusion of steel fibers into unconventional layups (cross-ply, quasi-isotropic, and helicoidal patterns) leads to the alleviation of directional dependence of mechanical properties, which is a limitation of the unidirectional samples with fibers. [1] https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concrete https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concr... [2] https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172
PEJOE 6y ago
Negative post here - interesting research but shame on reuters / researcher for pretending this is biomimicry. The article does not say at all how the concrete has anything to do with lobster shells. Further, rotating layers to change the bulk performance of materials composed of anisotropic plies is very old technology developed originally for aerospace / racing applications. Ansys has an entire package devoted to the analysis of structures made from anisotropic materials in this way.
- sradman 6y ago
  See FIG. 1. Hierarchical microstructure of the cuticle of the lobster (Homarus americanus; based on existing studies) from the paper: https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172
  - PEJOE 6y ago
    > Further, rotating layers to change the bulk performance of materials composed of anisotropic plies is very old technology developed originally for aerospace / racing applications. > Ansys has an entire package devoted to the analysis of structures made from anisotropic materials in this way. Also, if you read your link paper, they are not doing anything different that what has been known for a long time in long-fiber composites - see: https://www.liebertpub.com/cms/10.1089/3dp.2020.0172/asset/images/medium/3dp.2020.0172_figure2.jpg https://www.liebertpub.com/cms/10.1089/3dp.2020.0172/asset/i...
    - sradman 6y ago
      > they are not doing anything different that what has been known for a long time in long-fiber composites They are using a new material (concrete) and in-situ fabrication technique (extrusion/printing) that is at an early stage of development and doesn't seem to be performing well. I'm assuming that the type of empirical data produced by these experiments is a prerequisite to developing a finite element model for these materials/techniques. The worst case here is that civil engineers have to reinvent the knowledge that you believe other engineering disciplines have mastered using different materials. Computer guided in-situ reinforced concrete seems quite novel to me; perhaps that is a reflection of my own knowledge gap.
- analog31 6y ago
  >>> ...rotating layers to change the bulk performance of materials composed of anisotropic plies is very old technology developed originally for aerospace / racing applications. Indeed the original engineered composite material: Plywood.
dr_orpheus 6y ago
Links to the press release from the university [1] and the published study [2] have more information than this. The study is more specifically how different patterns of 3D printing concrete can increase strength over the conventional unidirectional printing in parallel lines. [1] https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concrete https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concr... [2] https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172
lailalessdad 6y ago
https://nplink.net/eck6p3am https://nplink.net/eck6p3am
slingnow 6y ago
This is a common technique when laying up carbon fiber / fiberglass parts. For each layer you put down, you vary the orientation of the fibers such that you don't end up with them all pointing in the same direction. This makes the material behave more like something homogeneous, like steel or aluminum, for example. I don't see what this has to do with lobster shells.
tutfbhuf 6y ago
Completely unrelated, but I somehow thought https://lobste.rs https://lobste.rs had invented a new shell (script) pattern at first.
beeforpork 6y ago
A criss-cross pattern is now called biomimicry? The following article has pictures and a video: https://www.theconstructionindex.co.uk/news/view/lobster-shells-inspire-stronger-3d-printed-concrete This is the normal top/bot pattern for 3D printing, right? I don't think it was copied from lobsters. Or am I missing something? Or is this totally misrepresented?
- maxerickson 6y ago
  The press release: https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concrete https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concr... Links the paper: https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 Figure 2 shows it is more than just criss-cross, the layout rotates for each layer following a pattern.
xrd 6y ago
This reminds me of tabby, concrete mixed with oyster shells. You can still find all these old buildings made of it from the Colonial days in Georgia and South Carolina. https://en.wikipedia.org/wiki/Tabby_concrete https://en.wikipedia.org/wiki/Tabby_concrete The "tech" you find in the oceans is truly amazing.
bumbada 6y ago
Mmmm, Reading the title I was expecting they were developing some system that made a super strong exo skeleton with a porous interior just like lobsters, or bones. They have done nothing like that. Criss cross printed lines? Adding reinforcement fibers? That is as old as 3D printing.
Blikkentrekker 6y ago
It would be nice if there were a picture of this pattern included.
StreamBright 6y ago
Biology has much to offer for us. There are millions of years of evolution encapsulated in some of the biological form and structures out there.
dghughes 6y ago
I was watching a documentary on electricity and it said how Volta used nature as inspiration. The alternating pattern of a Torpedo fish's muscle cells were the basis for the voltaic pile. The discs were mimicking how the many small cells of the fish combined small amounts of electricity into a larger amount.
earleybird 6y ago
As has been mentioned elsewhere, the reuters link is pretty much fluff (lobster, lobster, lobster) in that the RMIT paper https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 discusses Bouligand structures and uses the lobster as a biological example. Non biological examples abound. Structures for improving adhesion and strength in FDM printing (which arguably includes pumping concrete) is important and continually researched - basic, commercial and diy https://www.youtube.com/playlist?list=PLEOQTmIWJ_rmoqdFUCgKrNu_BsMVB7e1V https://www.youtube.com/playlist?list=PLEOQTmIWJ_rmoqdFUCgKr...
forshaper 6y ago
Similarly, abalone shell patterns were considered for ceramic armor plates. https://ceramics.org/ceramic-tech-today/ceramic-video/video-move-over-polymers-3d-printed-ceramic-body-armor-has-arrived https://ceramics.org/ceramic-tech-today/ceramic-video/video-...

88 points by quotha 6y ago

Biomimicry is fascinating. There's some good info at the Biomimicry Institute: https://biomimicry.org https://biomimicry.org

sradman 6y ago

The news release Bio-inspired: How lobsters can help make stronger 3D printed concrete [1] from RMIT University (with 1 minute video) and the paper Influences of Printing Pattern on Mechanical Performance of Three-Dimensional-Printed Fiber-Reinforced Concrete [2]: > Underperformed interfacial bond and anisotropic properties are often observed in three-dimensional-printed concrete, where the printing pattern is unidirectional. Such issues could be potentially alleviated by replicating microstructures of natural materials or applying different architectures, where printed layers are arranged into unique and unconventional patterns. > The addition of steel fibers leads to noticeable improvement on both compressive and flexural strengths of samples in any pattern compared with their counterparts without fibers. Besides, the inclusion of steel fibers into unconventional layups (cross-ply, quasi-isotropic, and helicoidal patterns) leads to the alleviation of directional dependence of mechanical properties, which is a limitation of the unidirectional samples with fibers. [1] https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concrete https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concr... [2] https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172

PEJOE 6y ago

Negative post here - interesting research but shame on reuters / researcher for pretending this is biomimicry. The article does not say at all how the concrete has anything to do with lobster shells. Further, rotating layers to change the bulk performance of materials composed of anisotropic plies is very old technology developed originally for aerospace / racing applications. Ansys has an entire package devoted to the analysis of structures made from anisotropic materials in this way.

sradman 6y ago
See FIG. 1. Hierarchical microstructure of the cuticle of the lobster (Homarus americanus; based on existing studies) from the paper: https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172
- PEJOE 6y ago
  > Further, rotating layers to change the bulk performance of materials composed of anisotropic plies is very old technology developed originally for aerospace / racing applications. > Ansys has an entire package devoted to the analysis of structures made from anisotropic materials in this way. Also, if you read your link paper, they are not doing anything different that what has been known for a long time in long-fiber composites - see: https://www.liebertpub.com/cms/10.1089/3dp.2020.0172/asset/images/medium/3dp.2020.0172_figure2.jpg https://www.liebertpub.com/cms/10.1089/3dp.2020.0172/asset/i...
  - sradman 6y ago
    > they are not doing anything different that what has been known for a long time in long-fiber composites They are using a new material (concrete) and in-situ fabrication technique (extrusion/printing) that is at an early stage of development and doesn't seem to be performing well. I'm assuming that the type of empirical data produced by these experiments is a prerequisite to developing a finite element model for these materials/techniques. The worst case here is that civil engineers have to reinvent the knowledge that you believe other engineering disciplines have mastered using different materials. Computer guided in-situ reinforced concrete seems quite novel to me; perhaps that is a reflection of my own knowledge gap.
analog31 6y ago
>>> ...rotating layers to change the bulk performance of materials composed of anisotropic plies is very old technology developed originally for aerospace / racing applications. Indeed the original engineered composite material: Plywood.

dr_orpheus 6y ago

Links to the press release from the university [1] and the published study [2] have more information than this. The study is more specifically how different patterns of 3D printing concrete can increase strength over the conventional unidirectional printing in parallel lines. [1] https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concrete https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concr... [2] https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172

lailalessdad 6y ago

https://nplink.net/eck6p3am https://nplink.net/eck6p3am

slingnow 6y ago

This is a common technique when laying up carbon fiber / fiberglass parts. For each layer you put down, you vary the orientation of the fibers such that you don't end up with them all pointing in the same direction. This makes the material behave more like something homogeneous, like steel or aluminum, for example. I don't see what this has to do with lobster shells.

tutfbhuf 6y ago

Completely unrelated, but I somehow thought https://lobste.rs https://lobste.rs had invented a new shell (script) pattern at first.

beeforpork 6y ago

A criss-cross pattern is now called biomimicry? The following article has pictures and a video: https://www.theconstructionindex.co.uk/news/view/lobster-shells-inspire-stronger-3d-printed-concrete This is the normal top/bot pattern for 3D printing, right? I don't think it was copied from lobsters. Or am I missing something? Or is this totally misrepresented?

maxerickson 6y ago
The press release: https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concrete https://www.rmit.edu.au/news/all-news/2021/jan/lobster-concr... Links the paper: https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 Figure 2 shows it is more than just criss-cross, the layout rotates for each layer following a pattern.

xrd 6y ago

This reminds me of tabby, concrete mixed with oyster shells. You can still find all these old buildings made of it from the Colonial days in Georgia and South Carolina. https://en.wikipedia.org/wiki/Tabby_concrete https://en.wikipedia.org/wiki/Tabby_concrete The "tech" you find in the oceans is truly amazing.

bumbada 6y ago

Mmmm, Reading the title I was expecting they were developing some system that made a super strong exo skeleton with a porous interior just like lobsters, or bones. They have done nothing like that. Criss cross printed lines? Adding reinforcement fibers? That is as old as 3D printing.

Blikkentrekker 6y ago

It would be nice if there were a picture of this pattern included.

StreamBright 6y ago

Biology has much to offer for us. There are millions of years of evolution encapsulated in some of the biological form and structures out there.

dghughes 6y ago

I was watching a documentary on electricity and it said how Volta used nature as inspiration. The alternating pattern of a Torpedo fish's muscle cells were the basis for the voltaic pile. The discs were mimicking how the many small cells of the fish combined small amounts of electricity into a larger amount.

earleybird 6y ago

As has been mentioned elsewhere, the reuters link is pretty much fluff (lobster, lobster, lobster) in that the RMIT paper https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 https://www.liebertpub.com/doi/10.1089/3dp.2020.0172 discusses Bouligand structures and uses the lobster as a biological example. Non biological examples abound. Structures for improving adhesion and strength in FDM printing (which arguably includes pumping concrete) is important and continually researched - basic, commercial and diy https://www.youtube.com/playlist?list=PLEOQTmIWJ_rmoqdFUCgKrNu_BsMVB7e1V https://www.youtube.com/playlist?list=PLEOQTmIWJ_rmoqdFUCgKr...

forshaper 6y ago

Similarly, abalone shell patterns were considered for ceramic armor plates. https://ceramics.org/ceramic-tech-today/ceramic-video/video-move-over-polymers-3d-printed-ceramic-body-armor-has-arrived https://ceramics.org/ceramic-tech-today/ceramic-video/video-...