scholarly journals Cyclic tensile-compressive tests on thin concrete boundary elements with a single layer of reinforcement prone to out-of-plane instability

2017 ◽  
Vol 16 (2) ◽  
pp. 859-887 ◽  
Author(s):  
Angelica Rosso ◽  
Lisandro A. Jiménez-Roa ◽  
João Pacheco de Almeida ◽  
Aydee Patricia Guerrero Zuniga ◽  
Carlos A. Blandón ◽  
...  
Keyword(s):  
Single Layer ◽  
Boundary Elements ◽  
Out Of Plane ◽  
Compressive Tests

Thermal Conductivity Reduction in Few-Layer Graphene

2011 ◽  
Author(s):  
Dhruv Singh ◽  
Jayathi Y. Murthy ◽  
Timothy S. Fisher
Keyword(s):  
Thermal Conductivity ◽  
Weak Coupling ◽  
Phonon Scattering ◽  
Single Layer ◽  
Acoustic Mode ◽  
Single Layer Graphene ◽  
Boltzmann Transport ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Few Layer Graphene

Using the linearized Boltzmann transport equation and perturbation theory, we analyze the reduction in the intrinsic thermal conductivity of few-layer graphene sheets accounting for all possible three-phonon scattering events. Even with weak coupling between layers, a significant reduction in the thermal conductivity of the out-of-plane acoustic modes is apparent. The main effect of this weak coupling is to open many new three-phonon scattering channels that are otherwise absent in graphene. The highly restrictive selection rule that leads to a high thermal conductivity of ZA phonons in single-layer graphene is only weakly broken with the addition of multiple layers, and ZA phonons still dominate thermal conductivity. We also find that the decrease in thermal conductivity is mainly caused by decreased contributions of the higher-order overtones of the fundamental out-of-plane acoustic mode. Moreover, the extent of reduction is largest when going from single to bilayer graphene and saturates for four layers. The results compare remarkably well over the entire temperature range with measurements of of graphene and graphite.

Interfacial Sliding in Back-End Interconnect Structures in Microelectronic Devices

2002 ◽  
Vol 716 ◽  
Author(s):  
K.A. Peterson ◽  
C. Park ◽  
I. Dutta
Keyword(s):  
Dielectric Material ◽  
Single Layer ◽  
Component Reliability ◽  
Force Microscopy ◽  
Interfacial Sliding ◽  
Microelectronic Devices ◽  
Atomic Force ◽  
Layer Structures ◽  
Out Of Plane ◽  
Plane Step

AbstractDeformation of interconnect structures at the back-end of microelectronic devices during processing or service can have a pronounced effect on component reliability. Here, we use atomic force microscopy (AFM) to study plastic deformation and interfacial sliding of Cu interconnects lines on Si. The behavior of both stand-alone Cu lines and lines embedded in a low K dielectric was studied. Following thermal cycling, changes were observed in the in-plane Cu line dimensions, as well as the out-of plane step height between Cu and dielectric in single layer structures. These were attributed to differential deformation of the Cu/Si and Cu/dielectric material pairs due to thermal expansion mismatch, accommodated by interfacial creep. These results are discussed in light of previous work on the mechanism of interfacial creep. Some preliminary results on the distortion of Cu lines due to package-level stresses are also presented.

In-plane and out-of-plane tensile behaviour of single-layer graphene sheets: a new interatomic potential

2020 ◽  
Vol 231 (7) ◽  
pp. 2915-2930
Author(s):  
Alessandra Genoese ◽  
Andrea Genoese ◽  
Ginevra Salerno
Keyword(s):  
Interatomic Potential ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Tensile Behaviour ◽  
Graphene Sheets ◽  
Layer Graphene ◽  
Out Of Plane

Out-of-Plane Performance of Reinforced Masonry Shear Walls Constructed with Boundary Elements

2019 ◽  
Vol 145 (8) ◽  
pp. 04019073 ◽  
Author(s):  
Tarek El-Hashimy ◽  
Mohamed Ezzeldin ◽  
Michael Tait ◽  
Wael El-Dakhakhni
Keyword(s):  
Shear Walls ◽  
Boundary Elements ◽  
Reinforced Masonry ◽  
Out Of Plane

Surface Micromachined Polysilicon Components Containing Continuous Hinges and Microrivets Used to Realize Three-Dimensional MEMS Structures

2001 ◽  
Vol 687 ◽  
Author(s):  
Edward S. Kolesar ◽  
Matthew D. Ruff ◽  
William E. Odom ◽  
Simon Y. Ko ◽  
Jeffery T. Howard ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Single Layer ◽  
Dimensional Structure ◽  
Plane Rotation ◽  
Arrow Head ◽  
Three Dimensional Structure ◽  
Out Of Plane ◽  
Open Window ◽  
Pass Through ◽  
Glass Reinforcement

AbstractA new polysilicon surface micromachining technique for fabricating and assembling three- dimensional structures has been developed. Single-layer polysilicon elements and laminated polysilicon panels incorporating trapped-glass reinforcement ribs have been successfully fabri- cated on a silicon substrate with robust and continuous hinges that facilitate out-of-plane rotation and assembly. To realize a stable three-dimensional structure, one of the device's elevatable panel components is terminated with an array of open windows, and the mating rotatable element has a matched set of protruding arrowheads/microrivets with flexible barbs that readily flex to facilitate their joining and assembly. Because the arrowhead/microrivet barb tip-to-barb tip sepa- ration is larger than the opening in the mating window, the barbs flex inward as they pass through the open window and then expand to their original shape upon exiting the window, re- sulting in a permanently latched joint and a three-dimensional structure. Three novel arrow- head/microrivet designs have been micromachined to facilitate the latching process, including a simple arrowhead, a high-aspect ratio arrowhead, and a rivet-like structure with a hemispherical shaped cap and a flexible split shank.

scholarly journals Thermal Resistance across Interfaces Comprising Dimensionally Mismatched Carbon Nanotube-Graphene Junctions in 3D Carbon Nanomaterials

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jungkyu Park ◽  
Vikas Prakash
Keyword(s):  
Carbon Nanotube ◽  
Thermal Resistance ◽  
Carbon Nanomaterials ◽  
Single Layer ◽  
Unit Cell ◽  
Single Layer Graphene ◽  
Interfacial Thermal Resistance ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Plane Direction

In the present study, reverse nonequilibrium molecular dynamics is employed to study thermal resistance across interfaces comprising dimensionally mismatched junctions of single layer graphene floors with (6,6) single-walled carbon nanotube (SWCNT) pillars in 3D carbon nanomaterials. Results obtained from unit cell analysis indicate the presence of notable interfacial thermal resistance in the out-of-plane direction (along the longitudinal axis of the SWCNTs) but negligible resistance in the in-plane direction along the graphene floor. The interfacial thermal resistance in the out-of-plane direction is understood to be due to the change in dimensionality as well as phonon spectra mismatch as the phonons propagate from SWCNTs to the graphene sheet and then back again to the SWCNTs. The thermal conductivity of the unit cells was observed to increase nearly linearly with an increase in cell size, that is, pillar height as well as interpillar distance, and approaches a plateau as the pillar height and the interpillar distance approach the critical lengths for ballistic thermal transport in SWCNT and single layer graphene. The results indicate that the thermal transport characteristics of these SWCNT-graphene hybrid structures can be tuned by controlling the SWCNT-graphene junction characteristics as well as the unit cell dimensions.

scholarly journals A Molecular Dynamics Study on Wrinkles in Graphene with Simply Supported Boundary under In-Plane Shear

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Jianzhang Huang ◽  
Qiang Han
Keyword(s):  
Molecular Dynamics ◽  
Single Layer ◽  
Single Layer Graphene ◽  
Propagation Process ◽  
Plane Shear ◽  
Simply Supported ◽  
Layer Graphene ◽  
Out Of Plane ◽  
Formation And Evolution ◽  
Dynamics Simulations

The formation and evolution mechanisms of wrinkling in a rectangular single layer graphene sheet (SLGS) with simply supported boundary subjected to in-plane shear displacements are investigated using molecular dynamics simulations. Through investigating the out-of-plane displacements of the key point atom, we clarify the wrinkling growth and propagation process. Our results show that the boundary condition plays important roles in the wrinkling deformation. And the dependence of wrinkling parameters on the applied shear displacements is captured. Based on the elasticity theory, the formation mechanism of graphene wrinkling is revealed from the viewpoint of elastic energy. The effects of aspect ratio of graphene, temperature, and loading velocity on graphene wrinkling parameters and patterns are also investigated.

scholarly journals Graphene on SiC(0001) inspected by dynamic atomic force microscopy at room temperature

2015 ◽  
Vol 6 ◽  
pp. 901-906 ◽  
Author(s):  
Mykola Telychko ◽  
Jan Berger ◽  
Zsolt Majzik ◽  
Pavel Jelínek ◽  
Martin Švec
Keyword(s):  
Electron Scattering ◽  
Room Temperature ◽  
Single Layer ◽  
Tunneling Current ◽  
Single Layer Graphene ◽  
Force Microscopy ◽  
Atomic Force ◽  
Scattering Effects ◽  
Out Of Plane ◽  
Theoretical Simulations

We investigated single-layer graphene on SiC(0001) by atomic force and tunneling current microscopy, to separate the topographic and electronic contributions from the overall landscape. The analysis revealed that the roughness evaluated from the atomic force maps is very low, in accord with theoretical simulations. We also observed that characteristic electron scattering effects on graphene edges and defects are not accompanied by any out-of-plane relaxations of carbon atoms.

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