اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدMechanical Properties of Gradient Copper Nano-Gyroid Cellular Structures: A Molecular Dynamics Study
91
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
Advanced manufacturing (AM) technologies, such as nanoscale additive manufacturing process, enable the fabrication of nanoscale architected materials which has received great attention due to their prominent properties. However, few studies delve into the functional gradient cellular architecture on nanoscale. This work studied the gradient nano-Gyroid architected material made of copper (Cu) by molecular dynamic (MD) simulations. The result reveals that, unlike homogeneous architecture, gradient Gyroid not only shows novel layer-by-layer deformation behavior, but also processes significantly better energy absorption ability. Moreover, this deformation behavior and energy absorption are predictable and designable, which demonstrates its highly programmable potential.
قيم البحث
اقرأ أيضاً
The use of CO2 as a natural refrigerant in data center cooling, oil recovery and in CO2 capture and storage which is gaining traction in recent years involves heat transfer between CO2 and the base fluid. A need arises to improve the thermal conducti
vity of CO2 to increase the process efficiency and reduce cost. One way to improve the thermal conductivity is through nanoparticle addition in the base fluid. The nanofluid in this study consists of copper (Cu) nanoparticle and CO2 as a base fluid. No experimental data are available on the thermal conductivity of CO2 based nanofluid. In this study, the effect of the formation of a nanolayer (or molecular layering) at the gas-solid interface on thermal conductivity is investigated using equilibrium molecular dynamics (EMD) simulations. This study also investigates the diameter effect of nanoparticle on the nanolayer, thermal conductivity and self-diffusion coefficient. In addition to this, diffusion coefficients are calculated for base fluid and nanofluid. The thickness of the dense semi-solid layer formed at the nanoparticle-gas interface is studied through radial distribution function (RDF) and density distribution around the nanoparticle. This thickness is found to increase with nanoparticle diameter. Enhancement in thermal conductivity and diffusion coefficient with nanoparticle diameter are strongly correlated, indicating that the dominant modes of heat and mass transfer are the same. The output of the current work demonstrates the enhancement in thermal conductivity due to nanoparticles addition which may improve data center cooling efficiency and CO2 capture and storing.
Schwarzites are porous crystalline structures with Gaussian negative curvature. In this work, we investigated the mechanical behavior and energy absorption properties of two carbon-based diamond schwarzites (D688 and D8bal). We carried out fully atom
istic molecular dynamics (MD) simulations. The optimized MD atomic models were used to generate macro-scale models for 3D-printing (PolyLactic Acid (PLA) polymer filaments) through Fused Deposition Modelling (FDM). Mechanical properties under uniaxial compression were investigated for both the atomic models and the 3D-printed ones. Mechanical testings were performed on the 3D-printed schwarzites where the deformation mechanisms were found to be similar to those observed in MD simulations. These results are suggestive of a scale-independent mechanical behavior that is dominated by structural topology. The structures exhibit high specific energy absorption and crush force efficiency ~0.8, which suggest that the 3D-printed diamond schwarzites are good candidates as energy-absorbing materials.
Recently, a new class of carbon allotrope called protomene was proposed. This new structure is composed of sp2 and sp3 carbon-bonds. Topologically, protomene can be considered as an sp3 carbon structure (~80% of this bond type) doped by sp2 carbons.
First-principles simulations have shown that protomene presents an electronic bandgap of ~3.4 eV. However, up to now, its mechanical properties have not been investigated. In this work, we have investigated protomene mechanical behavior under tensile strain through fully atomistic reactive molecular dynamics simulations using the ReaxFF force field, as available in the LAMMPS code. At room temperature, our results show that the protomene is very stable and the obtained ultimate strength and ultimate stress indicates an anisotropic behavior. The highest ultimate strength was obtained for the x-direction, with a value of ~110 GPa. As for the ultimate strain, the highest one was for the z-direction (~25% of strain) before protomene mechanical fracture.
Specific strength (strength/density) is a crucial factor while designing high load bearing architecture in areas of aerospace and defence. Strength of the material can be enhanced by blending with high strength component or, by compositing with high
strength fillers but both the options has limitations such as at certain load, materials fail due to poor filler and matrix interactions. Therefore, researchers are interested in enhancing strength of materials by playing with topology/geometry and therefore nature is best option to mimic for structures whereas, complexity limits nature mimicked structures. In this paper, we have explored Zeolite-inspired structures for load bearing capacity. Zeolite-inspired structure were obtained from molecular dynamics simulation and then fabricated via Fused deposition Modeling. The atomic scale complex topology from simulation is experimentally synthesized using 3D printing. Compressibility of as-fabricated structures was tested in different direction and compared with simulation results. Such complex architecture can be used for ultralight aerospace and automotive parts.
Triply Periodic Minimal Surfaces (TPMS) possess locally minimized surface area under the constraint of periodic boundary conditions. Different families of surfaces were obtained with different topologies satisfying such conditions. Examples of such f
amilies include Primitive (P), Gyroid (G) and Diamond (D) surfaces. From a purely mathematical subject, TPMS have been recently found in materials science as optimal geometries for structural applications. Proposed by Mackay and Terrones in 1991, schwarzites are 3D crystalline porous carbon nanocrystals exhibiting the shape of TPMS. Although their complex topology poses serious limitations on their synthesis with conventional nanoscale fabrication methods, such as Chemical Vapour Deposition (CVD), TPMS can be fabricated by Additive Manufacturing (AM) techniques, such as 3D Printing. In this work, we used an optimized atomic model of a schwarzite structure from the D family (D8bal) to generate a surface mesh that was subsequently used for 3D-printing through Fused Deposition Modelling (FDM). This D schwarzite was 3D-printed with thermoplastic PolyLactic Acid (PLA) polymer filaments. Mechanical properties under uniaxial compression were investigated for both the atomic model and the 3D-printed one. Fully atomistic Molecular Dynamics (MD) simulations were also carried out to investigate the uniaxial compression behavior of the D8bal atomic model. Mechanical testings were performed on the 3D-printed schwarzite where the deformation mechanisms were found to be similar to those observed in MD simulations. These results are suggestive of a scale-independent mechanical behavior that is dominated by structural topology.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
