Nathan Barton is the Group Leader of the Materials Modeling and Simulation Group in the Computational Engineering Division, and is the ASC/PEM Strength & Damage program element lead. Nathan earned a BS degree in mechanical engineering from the University of Illinois, graduating summa cum laude in 1996. Nathan’s PhD work was conducted through the Deformation Processes Laboratory at Cornell University, with support from a National Science Foundation graduate fellowship. After completing his PhD, Nathan spent several years at the University of California in San Diego before joining LLNL as a staff member. Nathan’s achievements were recognized in 2015 when he was selected to be among the first cohort to receive the LLNL Director's Early- Mid-Career Recognition Award, and in 2017 when he was named a Fellow of the American Physical Society.

Nathan's fields of interest center around computational mechanics of materials; with emphasis on multi-scale methods, crystal plasticity, multi-phase materials and phase transformations, dynamic behavior, large-scale computing, and connections to diffraction based experiments. In addition to his program oversight responsibilities, Nathan remains technically engaged in a variety of activities.

**Selected Publications**

- J.A. Moore,
**N.R. Barton**, J. Florando, R. Mulay, and M. Kumar. “Crystal plasticity modeling of beta phase deformation in Ti-6Al-4V.”*Modelling and Simulation in Materials Science and Engineering*, 25:075007, 2017. - M.C. Messner, M. Rhee, A. Arsenlis, and
**N.R. Barton**. “A crystal plasticity model for slip in hexagonal close packed metals based on discrete dislocation simulations.”*Modelling and Simulation in Materials Science and Engineering*, 25:044001, 2017. **N.R. Barton**. “Results from a new Cocks-Ashby style porosity model.”*AIP Conference Proceedings*, 1793:100029, 2017.- H.D. Carlton, J. Lind, M. Messner, N. Volkoff-Shoemaker, H. Barnard,
**N.R. Barton**, and M. Kumar. “Mapping Local Deformation Behavior in Single Cell Metal Lattice Structures.”*Acta Materialia*, 129:239–250, 2017. - S.A. Chester, J.V. Bernier,
**N.R. Barton**, L. Balogh, B. Clausen, and J.K. Edmiston. “Direct numerical simulation of deformation twinning in polycrystals.”*Acta Materialia*, 120:348–363, 2016. - J.A. Hawreliak, J. Lind, B. Maddox, M. Barham, M. Messner,
**N. Barton**, B.J. Jensen, and M. Kumar. “Dynamic Behavior of Engineered Lattice Materials.”*Scientific Reports*, 28094, 2016. - M.C. Messner, M.I. Barham, M. Kumar, and
**N.R. Barton**. “Wave propagation in equivalent continuums representing truss lattice materials.”*International Journal of Solids and Structures*, 73–74:55–66, 2015. - R.A. Austin,
**N.R. Barton**, J.E. Reaugh, and L.E. Fried. “Direct numerical simulation of shear localization and decomposition reactions in shock-loaded HMX crystal.”*Journal of Applied Physics*, 117:185902, 2015. Cover article and editor’s pick. - H.-S. Park, R. E. Rudd, R. M. Cavallo,
**N. R. Barton**, A. Arsenlis, J. L. Belof, K. J. M. Blobaum, B. S. El-dasher, J. N. Florando, C. M. Huntington, B. R. Maddox, M. J. May, C. Plechaty, S. T. Prisbrey, B. A. Remington, R. J. Wallace, C. E. Wehrenberg, M. J. Wilson, A. J. Comley, E. Giraldez, A. Nikroo, M. Farrell, G. Randall, and G. T. Gray III. “Grain Size Independent Plastic Flow at Ultra-high Pressures and Strain Rates.”*Physical Review Letters*, 114:065502, 2015. **N.R. Barton**, J.V. Bernier, R.A. Lebensohn, and D.E. Boyce. “The use of discrete harmonics in direct multi-scale embedding of polycrystal plasticity.”*Computer Methods in Applied Mechanics and Engineering*, 283:224–242, 2015.**N.R. Barton**, M. Rhee, S.F. Li, J.V. Bernier, M. Kumar, J.F. Lind, and J.F. Bingert. “Using high energy diffraction microscopy to assess a model for microstructural sensitivity in spall response.”*Journal of Physics: Conference Series*, 500:112007, 2014.**N.R. Barton**, and M. Rhee. “A multiscale strength model for tantalum over an extended range of strain rates.”*Journal of Applied Physics*, 114:123507, 2013.- J.N. Florando,
**N.R. Barton**, B.S. El-Dasher, J.M. McNaney, and M. Kumar. “Analysis of deformation twinning in tantalum single crystals under shock loading conditions.”*Journal of Applied Physics*, 113:083522, 2013. **N.R. Barton**, A. Arsenlis, and J. Marian. “A polycrystal plasticity model of strain localization in irradiated iron.”*Journal of the Mechanics and Physics of Solids*, 61:341-351, 2013.**N.R. Barton**, and J.V. Bernier. “A Method for Intragranular Orientation and Lattice Strain Distribution Determination.”*Journal of Applied Crystallography*, 45:1145-1155, 2012.**N.R. Barton**, J.V. Bernier, R. Becker, A. Arsenlis, R. Cavallo, J. Marian, M. Rhee, H.-S. Park, B. Remington, and R.T. Olson. “A multi-scale strength model for extreme loading conditions.”*Journal of Applied Physics*, 109:073501, 2011.**N.R. Barton,**J.V. Bernier, J. Knap, A.J. Sunwoo, E. Cerreta, T.J. Turner. “A call to arms for task parallelism in multi-scale materials modeling.”*International Journal for Numerical Methods in Engineering*, 86:744-764, 2011.- J.V. Bernier,
**N.R. Barton**, U. Lienert, and M.P. Miller. “Far-field high energy diffraction microscopy: A tool for intergranular orientation and strain analysis.”*The Journal of Strain Analysis for Engineering Design*, 46(7):527–547, 2011. - U. Lienert, S.F. Li, C.M. Hefferan, J. Lind, R.M. Suter, J.V. Bernier,
**N.R. Barton**, M.C. Brandes, M.J. Mills, M.P. Miller, B. Jakobsen, and W. Pantleon. “High-energy diffraction microscopy at the advanced photon source.”*JOM-J. Min. Met. Mat. S.*, 63(7):70–77, 2011. - H.R. Wenk,
**N.R. Barton**, M. Bortolotti, S. Vogel, M. Voltolini, G. Lloyd, and G. Gonzalez. “Dauphiné twinning and texture memory in polycrystalline quartz Part 3: Texture memory during phase transformation.”*Physics and Chemistry of Minerals*, 36(10):567–583, 2009. **N.R. Barton**, N.W. Winter, and J.E. Reaugh. “Defect evolution and pore collapse in crystalline energetic materials.”*Modelling and Simulation in Materials Science and Engineering*, 17:035003, 2009. Selected for the*MSMSE*Highlights of 2009 collection.**N.R. Barton**, J.V. Bernier, R.A. Lebensohn, and A.D. Rollett. Electron Backscatter Diffraction in Materials Science, chapter 11: Direct 3D simulation of plastic flow from EBSD data. Springer, second edition, 2009. ISBN 978-0387881355.**N.R. Barton**, J. Knap, A. Arsenlis, R. Becker, R.D. Hornung, and D.R. Jefferson. “Embedded polycrystal plasticity and adaptive sampling.”*International Journal of Plasticity*, 24:242-266, 2008.- J. Knap,
**N.R. Barton**, R.D. Hornung, A. Arsenlis, R. Becker, and D.R. Jefferson. “Adaptive sampling in hierarchical simulation.”*International Journal for Numerical Methods in Engineering*, 76:572-600, 2008. - J.V. Bernier,
**N.R. Barton**, and J. Knap. “Polycrystal plasticity based predictions of strain localization in metal forming.”*Journal of Engineering Materials and Technology*, 130(2):021020, 2008. **N.R. Barton**and H.R. Wenk. “Dauphiné twinning in polycrystalline quartz.”*Modelling and Simulation in Materials Science and Engineering*, 15:369–394, 2007.- A. Arsenlis,
**N.R. Barton**, R. Becker, and R.E. Rudd. “Generalized in situ adaptive tabulation for constitutive model evaluation in plasticity.”*Computer Methods in Applied Mechanics and Engineering*, 196:1–13, 2006. **N.R. Barton**, D.J. Benson, and R. Becker. “Crystal level continuum modeling of phase transformations: the alpha to epsilon transformation in iron.”*Modelling and Simulation in Materials Science and Engineering*, 13:707-731, 2005.**N.R. Barton**, D.J. Benson, and R. Becker. “Crystal level simulations using Eulerian finite element methods.”*AIP Conference Proceedin*gs, 712(1):1624–1629, 2004.**N.R. Barton**, D.E. Boyce, and P.R. Dawson. “Pole figure inversion using finite elements over Rodrigues space.”*Textures and Microstructures*, 35(2):113–144, 2002.**N.R. Barton**and P.R. Dawson. “On the spatial arrangement of lattice orientations in hot-rolled multiphase titanium.”*Modelling and Simulation in Materials Science and Engineering*, 9:433–463, 2001.**N.R. Barton**, P.R. Dawson, and M.P. Miller. “Yield strength asymmetry predictions from polycrystal elastoplasticity.”*Journal of Engineering Materials and Technology*, 121:230–239, 4 1999.

*LLNL-WEB-742567*