Toward large scale modeling of carbon nanotube systems with the mesoscopic distinct element method

Abstract In this work, we present a computational study of the small strain mechanics of freestanding ultrathin carbon nanotube (CNT) films under in-plane loading. The numerical modeling of the mechanics of representatively large specimens with realistic micro- and nanostructure is presented. Our simulations utilize the scalable implementation of the mesoscopic distinct element method of the waLBerla multi-physics framework. Within our modeling approach, CNTs are represented as chains of interacting rigid segments. Neighboring segments in the chain are connected with elastic bonds, resolving tension, bending, shear, and torsional deformations. These bonds represent a covalent bonding within the CNT surface and utilize enhanced vector model (EVM) formalism. Segments of the neighboring CNTs interact with realistic coarse-grained anisotropic van der Waals potential, enabling a relative slip of CNTs in contact. The advanced simulation technique allowed us to gain useful insights on the behavior of CNT materials. It was established that the energy dissipation during CNT sliding leads to extended load transfer that conditions size-independent, material-like mechanical response of the weakly bonded assemblies of CNTs.

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Friction Impact on Structural Evolution in Carbon Nanotube Yarn Formation: A Distinct Element Method Study

10.26226/morressier.5f5f8e69aa777f8ba5bd60a8 ◽

2020 ◽

Author(s):

Yuezhou Wang

Keyword(s):

Carbon Nanotube ◽

Distinct Element ◽

Structural Evolution ◽

Distinct Element Method ◽

Element Method

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Anisotropic Modeling with Geometric Multigrid Preconditioned Finite Element Method

Geophysics ◽

10.1190/geo2021-0592.1 ◽

2022 ◽

pp. 1-21

Author(s):

Qingtao Sun ◽

Runren Zhang ◽

Ke Chen ◽

Naixing Feng ◽

Yunyun Hu

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Large Scale ◽

Data Interpretation ◽

Scale Modeling ◽

Arbitrary Anisotropy ◽

Large Scale Modeling ◽

Element Method ◽

Geometric Multigrid ◽

Electromagnetic Surveys

Formation anisotropy in complicated geophysical environments can have a significant impact on data interpretation of electromagnetic surveys. To facilitate full 3D modeling of arbitrary anisotropy, we have adopted an h-version geometric multigrid preconditioned finite-element method based on vector basis functions. By using a structured mesh, instead of an unstructured one, our method can conveniently construct the restriction and prolongation operators for multigrid implementation, and then recursively coarsen the grid with the F-cycle coarsening scheme. The geometric multigrid method is used as a preconditioner for the biconjugate-gradient stabilized method to efficiently solve the linear system resulting from the finite-element method. Our method avoids the need of interpolation for arbitrary anisotropy modeling as in Yee’s grid-based finite-difference method, and it is also more capable of large-scale modeling with respect to the p-version geometric multigrid preconditioned finite-element method. A numerical example in geophysical well logging is included to demonstrate its numerical performance. Our h-version geometric multigrid preconditioned finite-element method is expected to help formation anisotropy characterization with electromagnetic surveys in complicated geophysical environments.

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1216 Large-scale agitation simulation based on Distinct Element Method on GPU supercomputer

The Proceedings of The Computational Mechanics Conference ◽

10.1299/jsmecmd.2013.26._1216-1_ ◽

2013 ◽

Vol 2013.26 (0) ◽

pp. _1216-1_-_1216-3_ ◽

Cited By ~ 1

Author(s):

Satori TSUZUKI ◽

Takayuki AOKI

Keyword(s):

Large Scale ◽

Distinct Element ◽

Distinct Element Method ◽

Simulation Based ◽

Element Method

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The Heather Hill landslide: an example of a large scale toppling failure in a natural slope

Canadian Geotechnical Journal ◽

10.1139/t91-051 ◽

1991 ◽

Vol 28 (3) ◽

pp. 410-422 ◽

Cited By ~ 22

Author(s):

M. A. Pritchard ◽

K. W. Savigny

Keyword(s):

British Columbia ◽

Large Scale ◽

Distinct Element ◽

Failure Surface ◽

Distinct Element Method ◽

Slope Engineering ◽

Columbia Mountains ◽

Toppling Failure ◽

Element Method

This paper is an inquiry into the suspected relationship between toppling and large deep-seated landslides along the Beaver Valley, Glacier National Park, British Columbia. The study area includes the Heather Hill landslide, one of several in the valley, and adjacent slopes that show varying degrees of toppling disturbance. The development of the Heather Hill landslide is simulated using the distinct element method of numerical analysis. The rock mass is modelled using deformable columns whose boundaries represent a coarse approximation of in situ discontinuity patterns. An intercalated change in the predominant lithologies and a concomitant change in discontinuity spacings are modelled by varying column thickness and material properties. The analysis confirms that a deep-seated failure surface can develop as a result of the toppling process. The intercalated change in lithologies and the related change in discontinuity spacings account for the curvilinear failure surface and the headscarp position of the Heather Hill landslide. These variables are believed to also control the overall distribution of landslides in the Beaver Valley. The paper demonstrates that the distinct element method provides an effective basis for quantitative analysis of large scale toppling. Many more applications will be needed to refine the geometric and material property generalizations used in this study. Nevertheless, the method appears to offer considerable promise for elucidating problems of rock slope behaviour in both slope engineering and geomorphology. Key words: toppling, landslide, British Columbia, mountains, numerical modelling, distinct element method.

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Rings and rackets from single-wall carbon nanotubes: manifestations of mesoscale mechanics

Soft Matter ◽

10.1039/c4sm00865k ◽

2014 ◽

Vol 10 (43) ◽

pp. 8635-8640 ◽

Cited By ~ 7

Author(s):

Yuezhou Wang ◽

Matthew R. Semler ◽

Igor Ostanin ◽

Erik K. Hobbie ◽

Traian Dumitrică

Keyword(s):

Carbon Nanotubes ◽

Carbon Nanotube ◽

Distinct Element ◽

Distinct Element Method ◽

Single Wall Carbon Nanotubes ◽

Single Walled Carbon Nanotube ◽

Single Wall Carbon ◽

Single Walled Carbon ◽

Element Method

We combine distinct element method simulations with experiments to reveal size dependencies and hence elucidate the mesoscale mechanical origin of rings and rackets assembled from single-walled carbon nanotube ropes.

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