Plastic deformation at dynamic compaction of aluminum nanopowder: Molecular dynamics simulations and mechanical model

2020 ◽  
Vol 124 ◽  
pp. 22-41 ◽  
Author(s):  
Alexander E. Mayer ◽  
Andrej A. Ebel ◽  
Mohammad K.A. Al-Sandoqachi
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Molecular Dynamics Simulations ◽  
Mechanical Model ◽  
Dynamic Compaction ◽  
Aluminum Nanopowder ◽  
Dynamics Simulations

scholarly journals Plastic Deformation Behavior of Bi-Crystal Magnesium Nanopillars with a { 10 1 ¯ 2 } Twin Boundary under Compression: Molecular Dynamics Simulations

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 750
Author(s):  
Xiaoyue Yang ◽  
Shuang Xu ◽  
Qingjia Chi
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Molecular Dynamics Simulations ◽  
Twin Boundary ◽  
Basal Slip ◽  
Boundary Migration ◽  
Plastic Deformation Process ◽  
Plastic Deformation Behavior ◽  
Schmid Factor ◽  
Dynamics Simulations

In this study, molecular dynamics simulations were performed to study the uniaxial compression deformation of bi-crystal magnesium nanopillars with a { 10 1 ¯ 2 } twin boundary (TB). The generation and evolution process of internal defects of magnesium nanopillars were analyzed in detail. Simulation results showed that the initial deformation mechanism was mainly caused by the migration of the twin boundary, and the transformation of TB into (basal/prismatic) B/P interface was observed. After that, basal slip as well as pyramidal slip nucleated during the plastic deformation process. Moreover, a competition mechanism between twin boundary migration and basal slip was found. Basal slip can inhibit the migration of the twin boundary, and { 10 1 ¯ 1 } ⟨ 10 1 ¯ 2 ⟩ twins appear at a certain high strain level ( ε = 0.104). In addition, Schmid factor (SF) analysis was conducted to understand the activations of deformation modes.

scholarly journals Molecular-Dynamics Simulations of the Emergence of Surface Roughness in a Polymer under Compression

Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7327
Author(s):  
Robin Vacher ◽  
Astrid S. de Wijn
Keyword(s):  
Molecular Dynamics ◽  
Surface Roughness ◽  
Plastic Deformation ◽  
Polyvinyl Alcohol ◽  
Molecular Dynamics Simulations ◽  
Complex Materials ◽  
Multi Scale ◽  
Dynamics Simulations ◽  
Scale Roughness ◽  
Mechanisms Of Plasticity

Roughness of surfaces is both surprisingly ubiquitous on all length scales and extremely relevant practically. The appearance of multi-scale roughness has been linked to avalanches and plastic deformation in metals. However, other, more-complex materials have mechanisms of plasticity that are significantly different from those of metals. We investigated the emergence of roughness in a polymer under compression. We performed molecular-dynamics simulations of a slab of solid polyvinyl alcohol that was compressed bi-axially, and we characterised the evolution of the surface roughness. We found significantly different behaviour than what was previously observed in similar simulations of metals. We investigated the differences and argue that the visco-elasticity of the material plays a crucial role.

Sign in / Sign up

Export Citation Format

Share Document