Molecular Dynamics of Shock Wave Interaction with Nanoscale Structured Materials
Item
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Title
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Molecular Dynamics of Shock Wave Interaction with Nanoscale Structured Materials
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Identifier
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d_2009_2013:54e690e1f3d8:11142
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identifier
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11645
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Creator
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Al-Qananwah, Ahmad K.,
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Contributor
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Yiannis Andreopoulos | Joel Koplik
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Date
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2012
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Language
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English
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Publisher
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City University of New York.
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Subject
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Mechanical engineering | Nanoscience | elastic constants | molecular dynamics | nano porous material | nano-scale structure | nano-shock tube | shock wave
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Abstract
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Typical theoretical treatments of shock wave interactions are based on a continuum approach, which cannot resolve the spatial variations in solids with nano-scale porous structure. Nano-structured materials have the potential to attenuate the strength of traveling shock waves because of their high surface-to-volume ratio. To investigate such interactions we have developed a molecular dynamics simulation model, based on Short Range Attractive interactions. A piston, modeled as a uni-directional repulsive force field translating at a prescribed velocity, impinges on a region of gas which is compressed to form a shock, which in turn is driven against an atomistic solid wall. Periodic boundary conditions are used in the directions orthogonal to the piston motion, and we have considered solids based on either embedded atom potentials (target structure) or tethered potential (rigid piston, holding wall). Velocity, temperature and stress fields are computed locally in both gas and solid regions, and displacements within the solid are interpreted in terms of its elastic constants. In this work we present results of the elastic behavior of solid structures subjected to shock wave impact and analysis of energy transport and absorption in porous materials. The results indicated that the presence of nano-porous material layers in front of a target wall reduced the stress magnitude detected inside and the energy deposited there by about 30 percent while, at the same time, its loading rate was decreased substantially.
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Type
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dissertation
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Source
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2009_2013.csv
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degree
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Ph.D.
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Program
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Engineering
