Talk:Bouligand structure

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The references have been added so that they are available when we add in the information. We will need to fix the linked pages. Some pages (like HAP) are linked in places where is it not the first occurrence of the word . Willin4RPI (talk) 18:59, 8 April 2020 (UTC)

Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 13 January 2020 and 30 April 2020. Further details are available on the course page. Student editor(s): Willin4RPI.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 18:16, 17 January 2022 (UTC)

Proposed Changes: Biomimetic Bouligand-Inspired Tool Paths for Additive Manufacturing

I want to discuss notable research relating to Bouligand structure deals with additive manufacturing of cement. Many researchers have created tool paths that deposit cement in a Bouligand structure in the hopes to increase the mechanical properties of the 3D structures, which is one of the most critical issues surrounding AM. This topic may be a subsection under “Biomimicry” and will explore development of specific Bouligand-inspired tool paths and how this impacts the mechanical properties of the AM parts. An image will be included in this section showing how the concrete is deposited in a Bouligand type pattern.

Mohamadreza Moini, Jan Olek, Jeffery P. Youngblood, Bryan Magee, Pablo D. Zavattieri. "Additive Manufacturing and Performance of Architectured Cement-Based Materials." Advanced Materials Vol 30, Issue 43. 2018. 201802123.

Willil13 (talk) 02:39, 5 March 2020 (UTC)willil13

Below find the rough outline I have written for the proposed section. I still need to copy references in from Sandbox (but they are listed above) and I am looking into open source images to use.

Additive manufacturing is a popular upcoming form of industry which allows for complex geometries and unique performance characteristics for AM parts. The main issue with mechanical properties of AM parts is the introduction of microstructural heterogeneities within layers of deposited material. These defects, including porosity and unique interfaces, result in anisotropy of the mechanical response of the workpiece, which is undesirable. To combat this anisotropic mechanical response, a Bouligand-inspired tool path is used to deposit the material in a twisted Bouligand structure. This results in a stress transfer mechanism which uses interlayer heterogeneities as stress deflection points, thus strengthening the workpiece at these points. Bouligand tool paths are used specifically in cement/ceramic deposition AM. Bouligand-inspired AM parts have been observed to behave better than cast elements under mechanical stress.

Pitch Angle

A critical parameter in the development of the Bouligand-inspired tool path is the pitch angle. The pitch angle γ is the angle at which the helicoidal structure is formed. The relative size of the pitch angle is critical for the mechanical response of a Bouligand-inspired AM toolpiece. For γ < 45° (small angle), interfacial crack growth and interfacial microcracking is observed. For 45° < γ < 90° (large pitch angle), dominant crack growth through the solid is observed.

Willil13 (talk) 17:38, 2 April 2020 (UTC)willil13

References

Proposed Changes: Mechanical Properties

I am looking to add analysis of the bouligand structure and specifically focus on its mechanical properties. Some of the sources that could be used to this end are listed below. This will look at the mechanical properties of the structure as found in nature, as well as compare property improvements in synthetic materials made using the bouligand structure. Specific properties covered are toughness, impact resistance, tensile, and compression strengths. All these would most likely go in as subsections under "Properties"

Bharath Natarajan and Jeffrey W. Gilman. “Bioinspired Bouligand cellulose nanocrystal composites: a review of mechanical properties”. Philos Trans A Math Phys Eng Sci. 2018 Feb 13; 376(2112): 20170050. Sheng Yin, Wen Yang, Junpyo Kwon, Amy Wat, Marc A. Meyers, Robert O. Ritchie. “Hyperelastic phase-field fracture mechanics modeling of the toughening induced by Bouligand structures in natural materials.” Journal of the Mechanics and Physics of Solids, Vol 131, Pages 204-220, Oct 2019. Xin Qin, Benjamin C. Marchi, Zhaoxu Meng, Sinan Keten. “Impact resistance of nanocellulose films with bioinspired Bouligand microstructures.” Nanoscale Advances, Issue 4, Pages 1351-1361, Jan 2019. Meyers, M. A., Chen, P. (2014). Biological Materials Science: Biological Materials, Bioinspired Materials, and Biomaterials. United Kingdom: Cambridge University Press.

--Nicholas.Hoffman (talk) 22:53, 3 March 2020 (UTC)

References

Proposed Edit: Biomimicry Section

This section will focus on the biomimetic applications of the bouligand structure. Some possible subjects to cover include: Crab shells used as templates for battery electrodes, Biomimetic Plywood, Nanocellulose films made with a builigand structure, Biomimetic nanocomposites,

The section will go over some of these examples and why the bouligand structure is beneficial. The methods used to create the biomimetic materials will also be discussed. The different examples will most likely be separated into a few smaller subsections.

Delorm (talk) 19:02, 5 March 2020 (UTC)

References

Proposed Changes: Examples in Nature

This section will cover a selection of animals that have been found to have bouligand structures. These species covered will be lobster and crab shells, arapaima fish scales, and the mantis shrimp . The purpose of the bouligand structure and relation to an evolutionary advantage for each species will be discussed. In addition, the mechanical properties that are relevant to each species’ application of the bouligand structure will be included. One or two micrograph images of the bouligand structure selected from one of the above species will be selected to show the physical structure.

Willin4RPI (talk) 17:49, 5 March 2020 (UTC)

I think it might also be helpful to have a section on how the bouligand structure physically is formed in nature. Is it templated by proteins as in abalone nacre? What proteins? etc. If that makes the nature section extra long, I can see if I can help out on this as well.

--Nicholas.Hoffman (talk) 18:18, 5 March 2020 (UTC)

That's a good idea, will include.

Willin4RPI (talk) 19:10, 6 March 2020 (UTC)

I just started looking at sources, there is a lot of information about how the Bouligand structure is characterized (ex. SAXS), which I wasn't planning on discussing. Would this information be worthwhile as an additional section, or do we already have enough to work with?

Willin4RPI (talk) 17:37, 12 March 2020 (UTC)

> This is what I have written so far for the Arapaima. Having some problems adding references in on this Talk page. Why are the formats for adding references different on the Talk page and Sandbox/regular page? Also, trying to add an image from this source, but I'm not sure how to. The source is from Nature Communications, which I believe is an acceptable place to use images from?

The Arapaima fish's outer scales are designed to resist piranha bites. This is achieved through the scales' hierarchical architecture. The thinness of the scales and their overlapping arrangement allow for flexibility during movement. This also influences how much a single scale will bend when a predator attacks.

In the species Arapaima gigas, each scale has two distinct structural regions which results in a scale that is resistant to puncture and bending. The outer layer is about 0.5 mm thick and is highly mineralized, which makes it hard, promoting predator tooth fracture. The inner layer is about 1 mm thick and is made of mineralized collagen fibrils arranged in a Bouligand structure. In the fibrils, collagen molecules are embedded with hydroxyapatite mineral nanocrystals. Collagen fibrils align in the same direction to make a layer of collagen lamella, of about 50 μm in thickness. Lamellae are stacked with a misalignment in orientation, creating a Bouligand structure.

When the scales bend during an attack, stress is distributed due to the corrugated morphology. The largest deformation is designed to occur in the inner core layer. The inner layer can support more plastic deformation than the brittle outer layer. This is because the Bouligand structure can adjust its lamellar layers to adapt to applied forces.

Adjustment of the Bouligand structure during loading has been measured using small angle X-ray scattering (SAXS). The two adjustment effects are the change in angle between the collagen fibrils and tensile axis, and the stretching of collagen fibrils. There are four mechanisms through which these adjustments occur. [NOTE: Add image of the four mechanisms here]

Fibrils rotate because of interfibrillar shear: As a tensile force is applied, fibrils rotate to align with the tensile direction. During deformation, the shear component of the applied stress causes the hydrogen bonds between fibrils to break and then reform after fibril adjustment. Collagen fibrils stretch: Collagen fibrils can elastically stretch, resulting in fibrils re-orientating to align with the tensile direction. Tensile opening of interfibillar gaps: Fibrils highly misoriented with the tensile direction can separate, creating an opening. "Sympathetic" lamella rotation: A lamella is able to rotate away from the tensile direction if it is sandwiched between two lamellae that are reorienting themselves towards the tensile direction. This can happen if the bonding between these lamellae is high.

Ψ refers to the angle between the tensile axis and the collagen fibril. Mechanisms 1 and 2 both decrease Ψ. Mechanisms 3 and 4 can increase Ψ, as in, the fibril moves away from the tensile axis. Fibrils with a small Ψ stretch elastically. Fibrils with a large Ψ are compressed, since adjacent lamellae contract in accordance with Poisson's ratio, which is a function of strain anisotropy.

Fibrils adapting to the loading environment enhance the flexibility of the lamellae. This contributes resistance to scale bending, and therefore increases fracture resistance. As a whole, the outer scale layer is hard and brittle, while the inner layer is ductile and tough. [15]

Willin4RPI (talk) 17:52, 1 April 2020 (UTC)

To above text, please see my Sandbox for a version with better formatting... also having problems added old references to the Talk page.

Willin4RPI (talk) 17:55, 1 April 2020 (UTC)

References