Dynamic response of phenolic resin and its carbon-nanotube composites to shock wave loading

Arman, Bedri; An, Qi; Luo, Sheng‐Nian; Desai, Tapan; Tonks, D. L.; Çağın, Tahir; Goddard, William A.

doi:10.1063/1.3524559

Cited by 35 publications

(32 citation statements)

References 27 publications

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“…If Eq. 7 is not satisfied, the stress response can be expected to depend on both time and position, as is the case with shock simulations [22]. Otherwise, a choice can be made in the deformation protocol.…”

Section: Upper Limits Of Frequencymentioning

confidence: 99%

Bi-modal polymer networks: Viscoelasticity and mechanics from molecular dynamics simulation

Sirk

Karim

Lenhart

et al. 2016

Polymer

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The high strain-rate rheological and mechanical properties of bi-modal epoxy polymer networks were characterized using molecular dynamics simulation. The complex Young's modulus was found by applying a cyclic sinusoidal strain over a wide range of temperatures spanning the glass transition. The non-linear stress response was studied in the glass transition region using uni-axial deformation. We discuss special considerations in computing viscoelastic properties at the high strain-rates available to molecular dynamics. As in experimental studies, the complex modulus is shown to be a function of the network composition and strain rate. However, the high strain-rate simulations performed here predict the existence of broad peaks in the temperature-dependent loss modulus and slow relaxation of the storage modulus. In general, it is observed that network compositions with larger amounts of short, stiff 4,4'methylenebis(cyclohexylamine) (MCA) cross-linkers lead to an increase in the mechanical glass transition temperature as well as the breadth of the glass transition compared to longer, more flexible poly(oxypropylene) diamine (POP) cross-linkers. When the networks of any composition were deformed beyond the linear region, the stress response displayed a plateau that was associated with the extension of network chains.

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Section: Upper Limits Of Frequencymentioning

confidence: 99%

Bi-modal polymer networks: Viscoelasticity and mechanics from molecular dynamics simulation

Sirk

Karim

Lenhart

et al. 2016

Polymer

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“…Among the available techniques to characterize the atomic‐level plastic deformation, the slip vector analysis is commonly used for polymeric systems. The slip vector of the α th bead is originally developed for crystalline materials but has been applied to the plastics deformation analysis in amorphous materials:

{bolds}_{α} = \max true({boldx}_{α β} - {boldX}_{α β} true)

which is the relative vector that has the maximum relative displacement of bead α with respect to its β th neighbor that is within the cutoff distance of

r_{normalc} = 2.5 σ

{boldx}_{α β}

and

{boldX}_{α β}

denote the relative vector between bead α and β in the current and preshocked states, respectively. The scalar slip of bead α is

s_{α} = | {bolds}_{α} |

.…”

Section: Simulation Setupmentioning

confidence: 99%

“…Among the molecular level simulations of shock impact on polymers, van Duin et al studied the decomposition of the poly‐dimethylsiloxane (PDMS) polymer through the ReaxFF‐MD simulation and its temperature, pressure and chemical environment dependence, where the initiation and process of the degradation was observed. Quantum MD techniques has been used to investigate the principal Hugoniot up to 790 GPa of warm dense polystyrene (PS), which is characterized by dissociation and ionization transition under the extreme conditions.…”

Section: Introductionmentioning

confidence: 99%

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Dynamics response of polyethylene polymer nanocomposites to shock wave loading

Michopoulos

Song

2015

J. Polym. Sci. Part B: Polym. Phys.

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The shock response of polyethylene polymer modified by nanoparticles (NP) is investigated using a coarsegrained molecular dynamics simulation. The u s -u p Hugoniot analysis yields a linear relationship under the range of particle velocity investigated, in agreement with previous simulation and experimental results. NP addition improves the mechanical properties of the composites, as reflected by the increased Young's modulus and yield strength especially in the case of shorter chain length of polymer. This is directly related to the increased shock impedance with NP volume fraction, as demonstrated by the enhanced pressure in the shocked state, slightly reduced microscopic deformation, and increased shock velocity. The layered structure with alternate soft and hard regions, with NP addition only in the hard regions, leads to significantly enhanced microscopic deformation in the soft regions. It is also important that the shock impedance difference between the soft and hard region to be large enough to facilitate the energy absorption through plastic deformation in the soft regions.

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“…[15][16][17][18][19][20][21][22] and computational engineering (e.g., Refs. [23][24][25][26][27] studies of polymers and polymer-based composites subjected to shock wave excitation, there are relatively few atomic-level computational studies, [28][29][30][31][32][33][34][35][36] which is understandable given the complexities of polymeric materials and the relatively large spatial and temporal scales over which post-shock relaxation in them occurs.…”

Section: Introductionmentioning

confidence: 99%

Molecular dynamics simulations of shock waves in cis-1,4-polybutadiene melts

Sewell

Thompson

2013

Journal of Applied Physics

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A molecular dynamics simulation study of the α-relaxation in a 1,4-polybutadiene melt as probed by the coherent dynamic structure factor A molecular-dynamics simulation study of dielectric relaxation in a 1,4-polybutadiene melt Molecular dynamics simulations of supported shock waves in monodisperse melts of cis-1,4-polybutadiene initially at atmospheric pressure and T ¼ 413 K were performed to study the shock-induced structural changes and post-shock relaxation. Simulations were performed for Rankine-Hugoniot shock pressures between 7.22 GPa and 8.26 GPa using the united-atom force field due to Smith and Paul [G. D. Smith and W. Paul, J. Phys. Chem. A 102, 1200 (1998)] for systems composed of chains containing 32, 64, or 128 united atoms. The sensitivity of the results to the non-bonded interaction potential was studied by comparing results obtained using the Lennard-Jones 12-6 potential from the original Smith and Paul force field to ones obtained when the 12-6 potential was replaced by the Buckingham exponential-6 potential. Several structural and mechanical properties were studied as functions of distance (time) behind the shock front. Bulk relaxation was characterized by calculating profiles of temperature, density, and principal and shear stress. Microscopic shock-induced structural rearrangement and relaxation were studied by calculating the ratio of Cartesian components of the mean-squared radius of gyration to corresponding values for the equilibrated material; dihedral angle distributions; and the distribution of, and second Legendre polynomial order parameter for, the angle formed by covalent bond vectors and the shock propagation direction. V C 2013 AIP Publishing LLC.

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Dynamic response of phenolic resin and its carbon-nanotube composites to shock wave loading

Cited by 35 publications

References 27 publications

Bi-modal polymer networks: Viscoelasticity and mechanics from molecular dynamics simulation

Bi-modal polymer networks: Viscoelasticity and mechanics from molecular dynamics simulation

Dynamics response of polyethylene polymer nanocomposites to shock wave loading

Molecular dynamics simulations of shock waves in cis-1,4-polybutadiene melts

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