John A. Mitchell

Computational Multiscale

jamitch@sandia.gov

Google Scholar

(505) 844-3435

Sandia National Laboratories, New Mexico
P.O. Box 5800
Albuquerque, NM 87185-1322

Brief Research and Project History

Nonlinear solver algorithms and implementations for solid mechanics
Engineering project management
Technology maturation and assessment
Constitutive model development (particularly Peridynamics)
GPU programming
Inverse problems
Monte Carlo models for grain growth in metals
Data analytics applied to metal material microstructures, insitu pyrometry data
Microstructure effects on dynamic response of additively manufactured metals

Current Activities

My work is at the confluence of engineering mechanics (especially continuum mechanics), materials and data science, mathematics, algorithms development, and software implementations. I am especially interested in bridging the gap between engineering and applied mathematics, and demonstrating and/or developing novel solutions and implementations for emerging problems

Microstructure effects on dynamic response of materials
Monte Carlo grain growth modeling of welding and additive manufacturing processes (see SPPARKS)
Data analytics & machine learning applied to material microstructures
Peridynamics constitutive model development towards multiscale analysis and upscaling
Processing and analysis of measured additive manufacturing pyrometer data

Recent Project Work and Activities

SPPARKS tutorial
Micromechanics calculations using Eshelby approach
Nonlinear kinematics for dielectrics (especially piezoelectric materials)
Mean curl discretization for 2D nonlinear magnetic diffussion equations
Vectorization of uniform gradient hexahedron for solid mechanics calculations on a GPU
Monte Carlo modeling of grain growth associated with weld process for metals

Other Activities and Interests

I’m from Homer Alaska and I like to visit there during the summer for camping/hiking/fishing and visiting with friends. I also like to exercise and at one time was very active in training for triathlons – now I just try to move a bit every day.

Education

B.S. Ocean Engineering Texas A&M University (1987)
M.S. Engineering Mechanics Virginia Tech (Advisor: J.N. Reddy, Thesis topic: Finite element formulation and implementation for piezoelectricity) (1992)
Ph.D. Mechanical Engineering Texas A&M University (Advisor: J.N. Reddy, Thesis topic: Multilevel/hierarchical preconditioning for p-finite elements) (1997)

Publications

Brittany Branch, Timothy Ruggles, John Miers, Caroline Massey, David Moore, Nathan Brown, Sakun Duwal, Stewart Silling, John Mitchell, Paul Specht, (2022). Understanding Phase and Interfacial Effects of Spall Fracture in Additively Manufactured Ti-5Al-5V-5Mo-3Cr https://doi.org/10.2172/1892129 Publication ID: 80360

Stewart Silling, John Mitchell, (2021). Modeling Spall in Additively Manufactured Steel With Local-Nonlocal Coupling https://doi.org/10.2172/1884654 Publication ID: 79559

Theron Rodgers, John Mitchell, Aaron Olson, Dan Bolintineanu, Andrew Vackel, N. Moore, (2021). Fast three-dimensional rules-based simulation of thermal-sprayed microstructures Computational Materials Science https://doi.org/10.1016/j.commatsci.2021.110437 Publication ID: 77781

Theron Rodgers, Daniel Moser, Fadi Abdeljawad, Olivia Jackson, Jay Carroll, Bradley Jared, Dan Bolintineanu, John Mitchell, J. Madison, (2021). Simulation of powder bed metal additive manufacturing microstructures with coupled finite difference-Monte Carlo method Additive Manufacturing https://doi.org/10.1016/j.addma.2021.101953 Publication ID: 77780

John Mitchell, Gerald Lofstead, Jeremy Trageser, (2021). Stitching additive manufacturing SPPARKS microstructure simulations https://doi.org/10.2172/1844314 Publication ID: 75516

Anh Tran, John Mitchell, Laura Swiler, Tim Wildey, (2020). An active learning high-throughput microstructure calibration framework for solving inverse structure–process problems in materials informatics Acta Materialia https://doi.org/10.1016/j.actamat.2020.04.054 Publication ID: 73364

Paul Specht, David Adams, John Mitchell, J. Brown, Brittany Branch, Stewart Silling, J. Wise, Donald Brown, Todd Palmer, (2020). Response of Wrought and Additively Manufactured 304L Stainless Steel at Mbar Stresses https://www.osti.gov/servlets/purl/1812161 Publication ID: 74340

Jay Lofstead, John Mitchell, Enze Chen, (2020). Stitch It Up: Using Progressive Data Storage to Scale Science Proceedings – 2020 IEEE 34th International Parallel and Distributed Processing Symposium, IPDPS 2020 https://www.osti.gov/servlets/purl/1775061 Publication ID: 73227

Bradley Jared, J. Madison, David Saiz, John Mitchell, Joshua Koepke, Thomas Ivanoff, (2020). Linking Pyrometry to Porosity in AM metals https://www.osti.gov/servlets/purl/1763169 Publication ID: 70865

John Mitchell, Thomas Ivanoff, Daryl Dagel, J. Madison, Bradley Jared, (2020). Linking pyrometry to porosity in additively manufactured metals Additive Manufacturing https://doi.org/10.1016/j.addma.2019.100946 Publication ID: 66528

Paul Specht, John Mitchell, David Adams, J. Brown, Stewart Silling, J. Wise, Todd Palmer , (2019). Shortening the Design and Certification Cycle for Additively Manufactured Materials by Improved Mesoscale Simulations and Validation Experiments: Fiscal Year 2019 Status Report https://doi.org/10.2172/1570554 Publication ID: 65576

Bradley Jared, J. Madison, John Mitchell, David Saiz, Joshua Koepke, Daryl Dagel, Thomas Ivanoff, (2019). Detecting Process Defects in Laser-Powder Bed Fusion https://www.osti.gov/servlets/purl/1643040 Publication ID: 65999

Thomas Ivanoff, J. Madison, John Mitchell, Daryl Dagel, Bradley Jared, (2019). Correlation of Porosity Defects with In-situ Pyrometry in AM 316L SS https://www.osti.gov/servlets/purl/1642630 Publication ID: 65369

John Mitchell, (2019). An Approach to Upscaling SPPARKS Generated Synthetic Microstructures of Additively Manufactured Metals https://doi.org/10.2172/1568985 Publication ID: 64960

Bradley Jared, John Mitchell, Thomas Ivanoff, David Saiz, Joshua Koepke, J. Madison, Laura Swiler, (2019). Defect Detection in Metal Additive Manufacturing Through Application of In-Situ Diagnostics https://www.osti.gov/servlets/purl/1641629 Publication ID: 70442

J. Madison, Thomas Ivanoff, John Mitchell, Daryl Dagel, Joshua Koepke, David Saiz, Bradley Jared, (2019). High Value Pyrometry-To-Defect Correspondence in Laser Powder Bed Fusion of 316L Stainless Steel https://www.osti.gov/servlets/purl/1641111 Publication ID: 69653

J. Madison, Theron Rodgers, John Mitchell, Hojun Lim, Corbett Battaile, Kyle Karlson, Alyssa Skulborstad, Maher Salloum, (2019). Materials Margins Assurance: Incorporating Material Variability in Simulation Tools and Code https://www.osti.gov/servlets/purl/1641377 Publication ID: 70061

John Mitchell, Thomas Ivanoff, Daryl Dagel, Bradley Jared, Joshua Koepke, David Saiz, Laura Swiler, (2019). Linking pyrometry to porosity in additive manufactured metals https://www.osti.gov/servlets/purl/1641333 Publication ID: 70077

Paul Specht, Stewart Silling, John Mitchell, Corbett Battaile, J. Brown, J. Wise, David Adams, Donald Brown, Todd Palmer, Joseph Michael, Michael Saavedra, (2019). Shortening the Design and Certification Cycle for Additively Manufactured Materials by Improved Mesoscale Simulations and Validation Experiments https://www.osti.gov/servlets/purl/1645212 Publication ID: 68419

John Mitchell, Thomas Ivanoff, J. Madison, Daryl Dagel, Bradley Jared, (2019). Linking in-situ pyrometry to pores https://www.osti.gov/servlets/purl/1639339 Publication ID: 67376

Bradley Jared, J. Madison, Thomas Ivanoff, Laura Swiler, David Saiz, Daryl Dagel, John Mitchell, Joshua Koepke, (2019). Defect Detection in Metal Additive Manufacturing Through Application of In-Situ Diagnostics https://www.osti.gov/servlets/purl/1639391 Publication ID: 67457

J. Madison, Daryl Dagel, Thomas Ivanoff, Bradley Jared, Joshua Koepke, John Mitchell, David Saiz, Laura Swiler, (2019). Defect Signatures for Metal Laser Powder-Bed Fusion https://www.osti.gov/servlets/purl/1639421 Publication ID: 67500

Theron Rodgers, Daniel Moser, Fadi Abdeljawad, Mario Martinez, Kurtis Ford, Bradley Trembacki, Kyle Johnson, John Mitchell, J. Madison, (2019). Calibrated Monte Carlo Models of Microstructure Evolution for Additive Manufacturing https://www.osti.gov/servlets/purl/1639467 Publication ID: 67582

Paul Specht, David Adams, Stewart Silling, John Mitchell, Corbett Battaile, J. Brown, J. Wise, Donald Brown, Todd Palmer, Joseph Michael, Michael Saavedra, (2019). Shortening the Design and Certification Cycle for Additively Manufactured Materials by Improved Mesoscale Simulations and Validation Experiments https://www.osti.gov/servlets/purl/1598928 Publication ID: 65567

Gerald Lofstead, John Mitchell, (2018). Lazy Minimal Eventually Consistent IO with Stitch https://www.osti.gov/servlets/purl/1592373 Publication ID: 59984

John Mitchell, (2018). Clustering to upscale microstructure morphologies https://www.osti.gov/servlets/purl/1806930 Publication ID: 59539

Paul Specht, David Adams, John Mitchell, Stewart Silling, J. Brown, J. Wise, Donald Brown, Todd Palmer, (2018). Response of Wrought and Additively Manufactured 304L Stainless Steel Under High Pressure High Strain-Rate Loading https://www.osti.gov/servlets/purl/1806931 Publication ID: 59552

Thomas Ivanoff, J. Madison, Joshua Koepke, Erich Swaller, Bradley Jared, John Mitchell, Laura Swiler, (2018). 3D Registration of Structure, Melt Pool History and Design in AM 316L Stainless Steel https://www.osti.gov/servlets/purl/1884475 Publication ID: 59634

Bradley Jared, J. Madison, Thomas Ivanoff, John Mitchell, Erich Schwaller, Joshua Koepke, David Saiz, Daryl Dagel, Harlan Brown-Shaklee, Laura Swiler, (2018). Defect Signatures for Metal Laser Powder Bed Fusion https://www.osti.gov/servlets/purl/1581712 Publication ID: 63670

Theron Rodgers, Daniel Moser, John Mitchell, Fadi Abdeljawad, Mario Martinez, Kyle Johnson, J. Madison, (2018). Powder Bed Modeling Big and Small: Simulating Microstructural Evolution from a Single Bead to (Closer to) the Part Scale https://www.osti.gov/servlets/purl/1582157 Publication ID: 63688

Thomas Ivanoff, J. Madison, Joshua Koepke, Bradley Jared, John Mitchell, Laura Swiler, (2018). 3D Characterization of Porosity in AM 316L SS and its Effect on Mechanical Behavior https://www.osti.gov/servlets/purl/1582148 Publication ID: 63694

Theron Rodgers, John Mitchell, J. Madison, (2018). Monte Carlo Simulation of Polycrystalline Additive Manufacturing Microstructures https://www.osti.gov/servlets/purl/1882035 Publication ID: 63097

John Mitchell, (2018). Towards upscaling microstructural effects using data analytics https://www.osti.gov/servlets/purl/1806536 Publication ID: 63205

Sophia Lefantzi, Dan Bolintineanu, Jeremy Lechman, J. Madison, Mario Martinez, John Mitchell, Daniel Moser, David Noble, Theron Rodgers, (2018). Toward Validated Multiscale Multiphysics Modeling for Additive Manufacturing Processes https://www.osti.gov/servlets/purl/1515726 Publication ID: 62149

Bradley Jared, Joshua Koepke, David Saiz, Laura Swiler, John Mitchell, J. Madison, Thomas Ivanoff, Kevin Webb, Jeffrey Rodelas, Erich Schwaller, (2018). Defect Signatures for Metal Laser Powder Bed Fusion https://www.osti.gov/servlets/purl/1501973 Publication ID: 61124

John Mitchell, (2018). A local/nonlocal plasticity model for upscaling microstructural effects https://www.osti.gov/servlets/purl/1505276 Publication ID: 61383

Uzoma Onunkwo, Anand Ganti, John Mitchell, Michael Scoggin, Richard Schroeppel, Brian Van Leeuwen, Michael Wolf, (2017). High Fidelity Simulations of Large-scale Wireless Networks (Part II – FY2017) https://doi.org/10.2172/1489863 Publication ID: 53778

Theron Rodgers, John Mitchell, Veena Tikare, (2017). A Monte Carlo model for 3D grain evolution during welding Modelling and Simulation in Materials Science and Engineering https://doi.org/10.1088/1361-651x/aa7f20 Publication ID: 57786

Theron Rodgers, Kyle Johnson, Judith Brown, Fadi Abdeljawad, J. Madison, John Mitchell, Veena Tikare, (2017). Modeling Microstructure Evolution During Metal Additive Manufacturing https://www.osti.gov/servlets/purl/1508469 Publication ID: 57562

Theron Rodgers, J. Madison, John Mitchell, Veena Tikare, (2017). NUMERICAL SIMULATION OF MICROSTRUCTURAL EVOLUTION DURING ADDITIVE MANUFACTURING OF METALS https://www.osti.gov/servlets/purl/1458098 Publication ID: 56602

John Mitchell, (2017). GrainGrowthModelingandNovelData AnalyticsforWeldProcess https://www.osti.gov/servlets/purl/1425305 Publication ID: 55055

John Mitchell, (2016). Potts model for grain growth during welding using SPPARKS https://www.osti.gov/servlets/purl/1397119 Publication ID: 52561

Veena Tikare, Andrew Castillo, Stephen Bond, J. Madison, John Mitchell, Theron Rodgers, (2016). Methods for Quantitative Characterization of Microstructures https://www.osti.gov/servlets/purl/1392762 Publication ID: 52204

John Mitchell, (2016). Novel Applicaon of Po0s Model for Grain Growth During Welding using SPPARKS https://www.osti.gov/servlets/purl/1365319 Publication ID: 49681

David Littlewood, John Mitchell, Aidan Thompson, (2015). Materials Modeling Capabiities https://www.osti.gov/servlets/purl/1340213 Publication ID: 42016

John Mitchell, (2015). Ordinary Isotropic Constitutive Models for Peridynamics https://www.osti.gov/servlets/purl/1506748 Publication ID: 46192

Veena Tikare, Philippe Weck, John Mitchell, (2015). Modeling of hydride precipitation and re-orientation https://doi.org/10.2172/1332940 Publication ID: 45718

David Littlewood, Stewart Silling, John Mitchell, Pablo Seleson, Stephen Bond, Michael Parks, Daniel Turner, Damon Burnett, Jakob Ostien, Max Gunzburger, (2015). Strong Local-Nonlocal Coupling for Integrated Fracture Modeling https://doi.org/10.2172/1221526 Publication ID: 45592

David Littlewood, Stewart Silling, Pablo Seleson, John Mitchell, (2015). Coupling Approaches for Integrating Meshfree Peridynamic Models with Classical Finite Element Analysis https://www.osti.gov/servlets/purl/1339330 Publication ID: 44646

John Mitchell, (2015). Ordinary Isotropic Peridynamic Models: Position Aware Viscoelastic(PAVE) https://www.osti.gov/servlets/purl/1249043 Publication ID: 43120

John Mitchell, Veena Tikare, (2015). Numerical Simulation of Ni Grain Growth in a Thermal Gradient https://www.osti.gov/servlets/purl/1246844 Publication ID: 42417

Andrew Baczewski, Adam Frees, John Gamble, Xujiao Gao, Noah Jacobson, John Mitchell, Ines Montano, Richard Muller, Erik Nielsen, (2015). Device-Level Models Using Multi-Valley Effective Mass https://www.osti.gov/servlets/purl/1240116 Publication ID: 42249

John Mitchell, (2015). Ordinary Isotropic Peridynamic Models; Position Aware Linear Solid (PALS) https://www.osti.gov/servlets/purl/1239086 Publication ID: 41642

Philippe Weck, Eunja Kim, Veena Tikare, John Mitchell, (2015). Mechanical properties of zirconium alloys and zirconium hydrides predicted from density functional perturbation theory Dalton Transactions https://doi.org/10.1039/c5dt03403e Publication ID: 45043

Richard Muller, John Aidun, Andrew Baczewski, Xujiao Gao, Tzvetan Metodi, John Mitchell, Jonathan Sterk, John Gamble, Robin Blume-Kohout, Noah Jacobson, (2015). Silicon Qubits By Design https://www.osti.gov/servlets/purl/1244872 Publication ID: 41211

John Mitchell, Veena Tikare, (2014). Numerical Simulation of Ni Grain Growth in a Thermal Gradient https://www.osti.gov/servlets/purl/1315397 Publication ID: 39879

John Mitchell, (2014). Peridynamics Ordinary Isotropic Plasticity Model https://www.osti.gov/servlets/purl/1367575 Publication ID: 39541

David Littlewood, Stewart Silling, Pablo Seleson, John Mitchell, (2014). Integrating Meshfree Peridynamic Models with Classical Finite Element Analysis https://www.osti.gov/servlets/purl/1242046 Publication ID: 39224

John Mitchell, (2014). A Simple One Step Line Search For Use in Quasi-static Solid Mechanics Contact Calculations https://www.osti.gov/servlets/purl/1502170 Publication ID: 38203

Stewart Silling, John Mitchell, (2014). Unifying the mechanics of continua cracks and particles https://www.osti.gov/servlets/purl/1496960 Publication ID: 37911

John Mitchell, Stewart Silling, David Littlewood, (2014). Ordinary Isotropic Peridynamic Models\\ Position Aware Linear Solid (PALS) https://www.osti.gov/servlets/purl/1497522 Publication ID: 37360

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