Simulation of Void Growth at High Strain-Rate

1998 ◽  
Vol 539 ◽  
Author(s):  
J. Belak ◽  
R. Minich
Keyword(s):  
Molecular Dynamics ◽  
Perfect Crystal ◽  
Dislocation Nucleation ◽  
Growth Exponent ◽  
Face Centered Cubic ◽  
Dynamics Modeling ◽  
Cubic Metals ◽  
Embedded Atom ◽  
Molecular Dynamics Modeling ◽  
Face Centered

AbstractThe dynamic fracture (spallation) of ductile metals is known to initiate through the nucleation and growth of microscopic voids. Here, we apply atomistic molecular dynamics modeling to the early growth of nanoscale (2nm radius) voids in face centered cubic metals using embedded atom potential models. The voids grow through anisotropic dislocation nucleation and emission into a cuboidal shape in agreement with experiment. The mechanism of this nucleation process is presented. The resulting viscous growth exponent at late times is about three times larger than expected from experiment for microscale voids, suggesting either a length scale dependence or a inadequacy of the molecular dynamics model such as the perfect crystal surrounding the void.

Molecular Dynamics Simulation of the Solidification of Liquid Nickel Nanowires

2007 ◽  
Vol 121-123 ◽  
pp. 1053-1056
Author(s):  
Guo Rong Zhong ◽  
Qiu Ming Gao
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Dynamics Simulation ◽  
Face Centered Cubic ◽  
Liquid Nickel ◽  
Cooling Rates ◽  
Final Structure ◽  
Embedded Atom ◽  
Nickel Nanowires ◽  
Face Centered

Molecular dynamics simulation of the solidification behavior of liquid nickel nanowires has been carried out based on the embedded atom potential with different cooling rates. The nanowires constructed with a face-centered cubic structure and a one-dimensional (1D) periodical boundary condition along the wire axis direction. It is found that the final structure of Ni nanowires strongly depend on the cooling rates during solidification from liquid. With decreasing cooling rates the final structure of the nanowires varies from amorphous to crystalline via helical multi-shelled structure.

MOLECULAR DYNAMICS SIMULATIONS OF STRUCTURAL PROPERTIES OF CuNi ALLOYS DURING THE COOLING PROCESS AT HIGH PRESSURE

2020 ◽  
Vol 65 (10) ◽  
pp. 10-17
Author(s):  
Thao Nguyen Thi ◽  
Giang Bui Thi Ha ◽  
Linh Tran Phan Thuy ◽  
Hop Nguyen Van ◽  
Chung Pham Do ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
High Pressure ◽  
Molecular Dynamics Simulations ◽  
Sudden Change ◽  
Face Centered Cubic ◽  
Cooling Process ◽  
Embedded Atom ◽  
The Face ◽  
Face Centered ◽  
Dynamics Simulations

Molecular dynamics simulations of Cu80Ni20 (Cu:Ni = 8:2) model with the size of 8788 atoms have been carried out to study the structure and mechanical behavior at high pressure of 45 GPa. The interactions between atoms of the system were calculated by the Quantum Sutton-Chen embedded-atom potentials. The crystallization has occurred during the cooling process with a cooling rate of 0.01 K\ps. The temperature range of the phase transition is determined based on the sudden change of atomic potential during the cooling process. There is also a sudden change in the number of individual atoms in the sample. At a temperature of 300 K, both Ni and Cu atoms are crystallized into the face-centered cubic (FCC) and the hexagonal close-packed (HCP) phases, respectively. The mechanical characteristics of the sample at 300 K were also analyzed in detail through the determination of elastic modulus, number of atoms, and void distribution during the tensile process.

Molecular Dynamics Modeling of Thermal Transport in Damaged Continua

2008 ◽  
Author(s):  
Navin Kumar ◽  
Kishore Pochiraju
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Dynamics Modeling ◽  
Damage State ◽  
Damage Propagation ◽  
Embedded Atom ◽  
Solid Gold ◽  
Change Behavior ◽  
Molecular Dynamics Modeling ◽  
Atomic Interactions

The interaction between the damage state and the thermal conductivity is studied in this paper. The damage propagation and the effective thermal conductivity of the damaged continuum is studied using equilibrium molecular dynamics (EMD) method based on the Green-Kubo relation. A solid gold lattice is considered and the damage is initiated and propagated by stretching two opposite ends while system is maintained at constant volume, constant temperature (NVT) condition. Both Lennard-Jones (LJ) 6–12 and embedded-atom method (EAM) potentials are used to model the inter-atomic interactions. Results are presented illustrating the load-displacement relationship during damage growth and the thermal conductivity change behavior for a selected crack length.

Molecular Dynamics Study on Interaction between Voids for Pure Aluminum

2010 ◽  
Vol 452-453 ◽  
pp. 845-848
Author(s):  
Shu Sheng Xu ◽  
Xiang Guo Zeng ◽  
Hua Yan Chen
Keyword(s):  
Molecular Dynamics ◽  
Pure Aluminum ◽  
Critical Distance ◽  
Atomic Scale ◽  
Embedded Atom Method ◽  
Face Centered Cubic ◽  
Embedded Atom ◽  
Modified Embedded Atom Method ◽  
Face Centered ◽  
The Impact

The voids in pure Aluminum always exit in the manufacturing process. The Modified Embedded Atom Method (MEAM) potential is employed in the molecular dynamics (MD) simulation at atomic scale to investigate the interaction between voids under the impact loading for pure Aluminum. The distance between the voids distributed along the loading orientation affects the failure mechanism seriously. The results show that there are 3 kinds of mechanisms with the change of the distance between voids: 1) coalescence takes place within a critical distance between voids under extra loading, 2) when the distance between voids reaches a certain value, each void cracks at 4 locations along with the slide direction <110> of face-centered cubic (fcc), respectively, 3) a stress shield zone appears when the ligament between the voids is at the size between the cases mentioned above, which brings out the phenomena that each of the voids cracks only at 2 locations, and no crack appeared at the stress shield zone.

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