A molecular dynamics investigation into the size-dependent buckling behavior of a novel three-dimensional metallic carbon nanostructure (T6)

2016 ◽  
Vol 97 ◽  
pp. 125-131 ◽  
Author(s):  
R. Ansari ◽  
S. Ajori ◽  
R. Hassani
2021 ◽  
Vol 11 (8) ◽  
pp. 3404
Author(s):  
Majid Hejazian ◽  
Eugeniu Balaur ◽  
Brian Abbey

Microfluidic devices which integrate both rapid mixing and liquid jetting for sample delivery are an emerging solution for studying molecular dynamics via X-ray diffraction. Here we use finite element modelling to investigate the efficiency and time-resolution achievable using microfluidic mixers within the parameter range required for producing stable liquid jets. Three-dimensional simulations, validated by experimental data, are used to determine the velocity and concentration distribution within these devices. The results show that by adopting a serpentine geometry, it is possible to induce chaotic mixing, which effectively reduces the time required to achieve a homogeneous mixture for sample delivery. Further, we investigate the effect of flow rate and the mixer microchannel size on the mixing efficiency and minimum time required for complete mixing of the two solutions whilst maintaining a stable jet. In general, we find that the smaller the cross-sectional area of the mixer microchannel, the shorter the time needed to achieve homogeneous mixing for a given flow rate. The results of these simulations will form the basis for optimised designs enabling the study of molecular dynamics occurring on millisecond timescales using integrated mix-and-inject microfluidic devices.


2003 ◽  
Vol 805 ◽  
Author(s):  
Frohmut Rösch ◽  
Christoph Rudhart ◽  
Peter Gumbsch ◽  
Hans-Rainer Trebin

ABSTRACTThe propagation of mode I cracks in a three-dimensional icosahedral model quasicrystal has been studied by molecular dynamics techniques. In particular, the dependence on the plane structure and the influence of clusters have been investigated. Crack propagation was simulated in planes perpendicular to five-, two- and pseudo-twofold axes of the binary icosahedral model.Brittle fracture without any crack tip plasticity is observed. The fracture surfaces turn out to be rough on the scale of the clusters. These are not strictly circumvented, but to some extent cut by the dynamic crack. However, compared to the flat seed cracks the clusters are intersected less frequently. Thus the roughness of the crack surfaces can be attributed to the clusters, whereas the constant average heights of the fracture surfaces reflect the plane structure of the quasicrystal. Furthermore a distinct anisotropy with respect to the in-plane propagation direction is found.


1993 ◽  
Vol 317 ◽  
Author(s):  
N.A. Marks ◽  
P. Guan ◽  
D.R. Mckenzie ◽  
B.A. PailThorpe

ABSTRACTMolecular dynamics simulations of nickel and carbon have been used to study the phenomena due to ion impact. The nickel and carbon interactions were described using the Lennard-Jones and Stillinger-Weber potentials respectively. The phenomena occurring after the impact of 100 e V to 1 keV ions were studied in the nickel simulations, which were both two and three-dimensional. Supersonic focussed collision sequences (or focusons) were observed, and associated with these focusons were unexpected sonic bow waves, which were a major energy loss mechanism for the focuson. A number of 2D carbon films were grown and the stress in the films as a function of incident ion energy was Measured. With increasing energy the stress changed from tensile to compressive and reached a maximum around 50 eV, in agreement with experiment.


1994 ◽  
Vol 373 ◽  
Author(s):  
Roger E. Stoller

AbstractA series of high-energy, up to 20 keV, displacement cascades in iron have been investigated for times up to 200 ps at 100 K using the method of molecular dynamics simulation. Thesimulations were carried out using the MOLDY code and a modified version of the many-bodyinteratomic potential developed by Finnis and Sinclair. The paper focuses on those results obtained at the highest energies, 10 and 20 keV. The results indicate that the fraction of the Frenkel pairs surviving in-cascade recombination remains fairly high in iron and that the fraction of the surviving point defects that cluster is lower than in materials such as copper. In particular, vacancy clustering appears to be inhibited in iron. Some of the interstitial clusters were observed to exhibit an unexpectedly complex, three-dimensional morphology. The observations are discussed in terms of their relevance to microstructural evolution and mechanical property changes in irradiated iron-based alloys.


2009 ◽  
Vol 60-61 ◽  
pp. 315-319 ◽  
Author(s):  
W.W. Zhang ◽  
Qing An Huang ◽  
H. Yu ◽  
L.B. Lu

Molecular dynamics simulations are carried out to characterize the mechanical properties of [001] and [110] oriented silicon nanowires, with the thickness ranging from 1.05nm to 3.24 nm. The nanowires are taken to have ideal surfaces and (2×1) reconstructed surfaces, respectively. A series of simulations for square cross-section Si nanowires have been performed and Young’s modulus is calculated from energy–strain relationship. The results show that the elasticity of Si nanowires is strongly depended on size and surface reconstruction. Furthermore, the physical origin of above results is analyzed, consistent with the bond loss and saturation concept. The results obtained from the molecular dynamics simulations are in good agreement with the values of first-principles. The molecular dynamics simulations combine the accuracy and efficiency.


Biochemistry ◽  
1990 ◽  
Vol 29 (45) ◽  
pp. 10317-10322 ◽  
Author(s):  
Lennart Nilsson ◽  
Agneta Aahgren-Staalhandske ◽  
Ann Sofie Sjoegren ◽  
Solveig Hahne ◽  
Britt Marie Sjoeberg

2018 ◽  
Vol 232 ◽  
pp. 8-10 ◽  
Author(s):  
Yang Gao ◽  
Guojian Li ◽  
Yongjun Piao ◽  
Shiying Liu ◽  
Shan Liu ◽  
...  

2021 ◽  
Vol 11 (21) ◽  
pp. 10434
Author(s):  
Faraz Kiarasi ◽  
Masoud Babaei ◽  
Kamran Asemi ◽  
Rossana Dimitri ◽  
Francesco Tornabene

The present work studies the buckling behavior of functionally graded (FG) porous rectangular plates subjected to different loading conditions. Three different porosity distributions are assumed throughout the thickness, namely, a nonlinear symmetric, a nonlinear asymmetric and a uniform distribution. A novel approach is proposed here based on a combination of the generalized differential quadrature (GDQ) method and finite elements (FEs), labeled here as the FE-GDQ method, while assuming a Biot’s constitutive law in lieu of the classical elasticity relations. A parametric study is performed systematically to study the sensitivity of the buckling response of porous structures, to different input parameters, such as the aspect ratio, porosity and Skempton coefficients, along with different boundary conditions (BCs) and porosity distributions, with promising and useful conclusions for design purposes of many engineering structural porous members.


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