Atomic Scale Deformation Mechanisms of Amorphous Polyethylene under Tensile Loading M.A. Tschopp*, J.L. Bouvard, D.K. Ward, M.F. Horstemeyer Center for Advanced Vehicular Systems (CAVS), Mississippi State University Supported by contract: Army W56HZV08C0236 and Department of Energy February 27-March 3, 2011 – San Diego, California
24
Embed
Atomic Scale Deformation Mechanisms of Amorphous ... · Atomic Scale Deformation Mechanisms of Amorphous Polyethylene under Tensile Loading M.A. Tschopp*, J.L. Bouvard, D.K. Ward,
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Atomic Scale Deformation Mechanisms of Amorphous Polyethylene under Tensile Loading
M.A. Tschopp*, J.L. Bouvard, D.K. Ward, M.F. HorstemeyerCenter for Advanced Vehicular Systems (CAVS),
Mississippi State University
Supported by contract: Army W56HZV08C0236and Department of Energy
Multiscale models for polymer material response: How does this nanoscale information and its uncertainty enter into multiscale models of polymer response?
Introduction
February 27-March 3, 2011 – San Diego, California
Simulation Methodology
[1] Mayo, Olafson, Goddard, J. Phys. Chem., (1990)
Amorphous Polyethylene Potential• United atom method potential• Dreiding potential [1]
Initialization/Equilibration• Monte Carlo self-avoiding random walk to generate amorphous cell with 4 step equilibration: (1) Relax in NVT @ 500K, (2) Relax in NPT @ 500K, (3) Cool to deformation temperature, and (4) Relax in NPT at temperature 3
Simulation MethodologyDeformation• Uniaxial strain of 1010 s-1 in the loading direction (e.g., perpendicular to GB)• NPT equations of motion are used for zero stress condition on the lateral boundaries (except for simulations exploring lateral boundary conditions)• Periodic output of atomic coordinates for postprocessing along with macroscopic stress, energy, and strain components
• Developing a generalized framework for investigating amorphous polymer deformation response at the nanoscale• Investigating sources of uncertainty in these deformation simulations• Quantitatively studying the evolution in structure for informing internal state variable models at higher length scales.
February 27-March 3, 2011 – San Diego, California
Main Points:
• Developing a generalized framework for investigating amorphous polymer deformation response at the nanoscale• Investigating sources of uncertainty in these deformation simulations• Quantitatively studying the evolution in structure for informing internal state variable models at higher length scales.
Conclusions
Thank you!
February 27-March 3, 2011 – San Diego, California
Thank you for your time!Questions?Corresponding authorMark [email protected]