Practicum Experience(s)
Sandia National Laboratories, New Mexico (2025)
Summary of Research
My research aims to develop a new framework for studying anisotropic material behavior under extreme loading conditions and elevated strain rates. This will involve a combination of experimental and numerical approaches to better understand the performance of specific sheet metals that are commonly used within the nuclear stockpile. Manufacturing these materials induces unique plastic anisotropy that should be understood to accurately predict deformation and fracture when subjected to multi-axial and extreme loading conditions. To traditionally calibrate anisotropic material models, full-scale testing methods that are costly and time-consuming are currently being employed. My work aims to reduce the number of experiments required by leveraging data-rich experiments that contain all the stress states encountered in the first quadrant of the plane-stress yield locus. It is proposed that the plastic anisotropy can be obtained from a single test instead of multiple traditional tests, allowing engineers to make more informed decisions on material selection and predict the performance of components in extreme environments more accurately. This same experiment also has the potential to inform damage accumulation and ductile fracture models, providing insight into crack initiation and propagation in anisotropic materials. Additionally, this experiment can be performed at various velocities to study the rate-dependence of the plastic anisotropy, a critical factor in high-rate and impact loading failures. The first aim of my research is to solve the forward problem by conducting traditional material testing and finite element analysis to establish the ground truth of the material's behavior. The second aim will explore microstructural modeling as an alternative to traditional calibration techniques. The third aim is solving the inverse problem, identifying material properties through a single data-rich experiment. If successful, it could shift how material models are identified, making simulations more accurate and efficient and ultimately improving the safety and security of our stockpile.
Annual Program Review Abstracts
Publications
Journal Publications
1. J.L. Smith, J.D. Seidt, C.J. Fietek, and A. Gilat. “Taylor-Quinney coefficient determination from simultaneous strain and temperature measurements of uniform and localized deformation in tensile tests.” J. Mech. Phys. Solids, (2025). https://doi.org/10.1016/j.jmps.2025.106099
2. C.J. Fietek, E. Brizes, J. Milner. “Evaluation of High-Vacuum Annealing and Hot Isostatic Pressing on the Microstructure and Properties of an Additively Manufactured Niobium Alloy.” JOM, (2024). https://doi.org/10.1007/s11837-023-06320-5
3. Y.H. Park, C.J. Fietek, A. Love, and J. Sakai. “Damage Modeling in Additive Manufacturing Processes for Metals”, Int. J. Adv. Manuf. Technol., (2024). https://doi.org/10.1007/s00170-024-13108-7
4. C.J. Fietek, J.D. Seidt, H. Lim, and Y.P. Korkolis. “Rate-Dependent Hole-Expansion Experiments on Plastically Anisotropic Sheets.” JOM, (2023). https://doi.org/10.1007/s11837-023-06166-x
5. J. Nakai-Chapman, C.J. Fietek, A. Love, J. Sakai, and Y.H. Park. “Metal Additive Manufacturing Simulation Using Sequentially Coupled Thermomechanical Analysis with Johnson-Cook Constitutive Material Model”. Multiscale Multidiscip. Model. Exp. Des. (2023). https://doi.org/10.1007/s41939-023-00247-9
6. E. Corona, M. Spletzer, B.T. Lester and C.J. Fietek. “Validation of material models for puncture of 7075-T651 aluminum plate”. Int. J. Solids Struct., (2022). https://doi.org/10.1016/j.ijsolstr.2022.111893
Refereed Conference Proceedings
1. C.J. Fietek, J.D. Seidt, H. Lim, Y.P. Korkolis, “A Parametric Study of the Virtual Fields Method for Identification of Anisotropic Plasticity”. Oral presentation at NUMISHEET: The 13th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes, (Munich, DE: July, 2025). https://doi.org/10.1088/1742-6596/3104/1/012035
2. C.J. Fietek, E. Corona, and D. VanGoethem, “Puncture of Thin Aluminum 7075-T651 Plates” Oral presentation given at the 2024 Society of Experimental Mechanics Annual Conference, (Vancouver, WA: June 2024). https://doi.org/10.1007/978-3-031-85829-1_16
3. C.J. Fietek, “Validation of Complex Material Models using Hole-Expansion Experiments”. The Ohio State University Edward F. Hayes Advanced Research Forum, (2024). https://kb.osu.edu/handle/1811/104352
4. C.J. Fietek, J. Sakai, A. Love and Y.H. Park, “Damage Modeling in Metal Additive Manufacturing Process Simulations”. Proceedings of the ASME Pressure Vessel and Piping Conference (PVP), (2023). https://doi.org/10.1115/PVP2023-106347
5. J. Nakai-Chapman, C.J. Fietek, J. Sakai, and Y.H. Park. “METAL ADDITIVE MANUFACTURING SIMULATION USING SEQUENTIALLY COUPLED THERMO-MECHANICAL ANALYSIS”. Proceedings of the ASME Pressure Vessels and Piping Conference (PVP), (2022). https://doi.org/10.1115/PVP2022-84612
Conference Presentations
1. C.J. Fietek, H. Lim, J.D. Seidt, Y.P. Korkolis, “Advanced Prediction of the Structural Response of an Aluminum 6061-T6 Using the Crystal Plasticity Finite Element Method.” Oral presentation at the 35th Annual Rio Grande Symposium on Advanced Materials, (Albuquerque, NM: November 2025).
2. C.J. Fietek, J.D. Seidt, H. Lim, Y.P. Korkolis, “Exploring the Interaction of Plastic Anisotropy and Strain-Rate Sensitivity for 6061-T6 Aluminum.” Poster presented at the 2025 Materials Science and Technology (MS&T) 2025, (Columbus, OH: October, 2025).
3. C.J. Fietek, J.D. Seidt, H. Lim, Y.P. Korkolis, “A Parametric Study of the Virtual Fields Method for Identification of Anisotropic Plasticity”. Oral presentation at NUMISHEET: The 13th International Conference and Workshop on Numerical Simulation of 3D Sheet Metal Forming Processes, (Munich, DE: July, 2025). https://doi.org/10.1088/1742-6596/3104/1/012035
4. C.J. Fietek, J.D. Seidt, H. Lim, Y.P. Korkolis, “Calibration and Validation of Complex Material Models of a 6061-T6 Aluminum.” Poster presented at the 2025 U.S. DOE NNSA SSGF & LRGF Annual Program Review, (Washington, D.C.: June, 2025).
5. C.J. Fietek, J.D. Seidt, H. Lim, Y.P. Korkolis, “Validating Rate-Dependent Anisotropic Plasticity Models: Insights from Drop Tower Hole-Expansion Experiments.” Oral presentation at the 2025 SEM Annual Conference, (Milwaukee, WI: June, 2025).
6. C.J. Fietek, “Finding Direction Dependent Material Properties of Metals.” University finalist, oral presentation at 5th Annual Three Minute Thesis (3MT) at The Ohio State University, (Columbus, OH: February 2025). https://youtu.be/mRe4ZMpHiu4
7. C.J. Fietek, E. Corona, and D. VanGoethem, “Puncture of Thin Aluminum 7075-T651 Plates” Oral presentation given at the 2024 Society of Experimental Mechanics Annual Conference, (Vancouver, WA: June 2024).
8. C.J. Fietek, J.D. Seidt, H. Lim, and Y.P. Korkolis, “Hole Expansion Testing of Thin Sheet Materials at Various Strain Rates for Advanced Constitutive Model Calibration.” Oral presentation given at the 2023 Materials Science & Technology Technical Meeting and Exhibition, (Columbus, OH: October 2023).
9. C.J. Fietek, “Characterizing Microstructure and Properties of a Niobium Alloy Subject to Various Heat-Treatments.” Oral presentation presented as part of graduate student presentation competition at the 2023 GEM Annual Board Meeting & Conference, (Philadelphia, PA: September 2023). https://ntrs.nasa.gov/citations/20230011948
10. C.J. Fietek, J.D. Seidt, H. Lim, and Y.P. Korkolis. “Hole-Expansion Experiments on AA6061-T6 and SS-304 at Different Punch Velocities.” Poster presentation given as part of the graduate student poster competition at the 2023 GEM Annual Board Meeting & Conference, (Philadelphia, PA: September 2023).
11. S.L.B. Kramer, T. Ivanoff, A. Jones, E. Corona, M. Swanson, N.U. Huynh, C. McConnell, D. Johnson, C. Loeffler, J. Varga, D. Landry, F. Arnold, F. Aria, and C.J. Fietek. “Sandia Mechanics Challenge: Determining Mechanical Performance and Model Calibration Inputs for the Challenge Material and Fasteners.” Oral presentation at the 17th US National Congress on Computational Mechanics, (Albuquerque, NM: July 2023). http://dx.doi.org/10.2172/2430604
12. E. Corona, C.J. Fietek, D. VanGoethem, “Validation of Finite Element Models for Puncture of Al7075 Plates of Various Thickness.” Oral presentation at the 19th U.S. National Congress on Theoretical and Applied Mechanics, (Austin, TX: June 2022). https://doi.org/10.2172/2003676
13. C.J. Fietek, “Analysis of Element Size on Failure Model Performance.” Poster presentation as part of the 19th U.S. National Congress on Theoretical and Applied Mechanics, (Austin, TX: June 2022). https://doi.org/10.2172/2003475
14. C.J. Fietek, and J. Linford, “Virtual Additive Manufacturing.” Oral presentation given as part of the 26th Annual New Mexico State University Undergraduate Research & Creative Arts Symposium, (Las Cruces, NM: May, 2021).
Technical Reports
1. E. Corona and C.J. Fietek. “Mass Property Calculator.” Tech. Rep. SAND2022-8871 Sandia National Lab; Albuquerque, NM (2021). https://doi.org/10.2172/1874633
2. E. Corona and C.J. Fietek. “Effects of finite element discretization and model simplification on calculations of ductile failure initiation.” Tech. Rep. SAND2021-10905R Sandia National Lab; Albuquerque, NM, (2021). https://doi.org/10.2172/1819414
3. C.J. Fietek and Edmundo Corona. “Power Law Hardening Fit for Inconel 718 Material.” Tech. Rep. SAND2021-3955R Sandia National Lab; Albuquerque, NM (2021). https://doi.org/10.2172/1774745
4. E. Corona, C.M. Laursen, and C.J. Fietek. “Response of 304L stainless steel and 6061-T651 aluminum alloy at-40 C.” Tech. Rep. SAND2021-3978R Sandia National Lab; Albuquerque, NM (2021). https://doi.org/10.2172/1775054
5. E. Corona, S.L. Kramer, B.T. Lester, A. Jones, B. Sanborn, and C.J. Fietek. “Thermal-Mechanical Elastic-Plastic and Ductile Failure Model Calibrations for 6061-T651 Aluminum Alloy from Plate.” Tech. Rep. SAND2021-2983 Sandia National Lab; Albuquerque, NM (2021). https://doi.org/10.2172/1772885
6. E. Corona, S.L. Kramer, B.T. Lester, A. Jones, B. Sanborn, L. Shand, and C.J. Fietek. “Thermal-Mechanical Elastic-Plastic and Ductile Failure Model Calibrations for 304L Stainless Steel Alloy.” Tech. Rep. SAND2021-1752 Sandia National Lab, Albuquerque, NM (2021). https://doi.org/10.2172/1769256
7. C.J. Fietek. “Analysis of Element Size and Element Type on SS304L Material Model Performance.” Tech. Rep. SAND-2021-0567R, Sandia National Lab; Albuquerque, NM (2021). https://doi.org/10.2172/1762592
Awards
2nd place winner, Graduate Student Poster Contest, Materials Science and Technology (MS&T), 2025.
Society of Experimental Mechanics Student Ambassador, Society of Experimental Mechanics, 2025.
Engineering Graduate Student Ambassador, The Ohio State University, 2025.
University Finalist, Three Minute Thesis (3MT), The Ohio State University, 2025.
3rd place winner, Engineering Oral Presentation, The Ohio State University's 36th Annual Edward F. Hayes Advanced Research Forum, 2024
4th place winner, Early PhD Oral Presentation Contest, GEM Annual Board Meeting & Conference, 2023
Crimson Scholar Honors, New Mexico State University, 2017-2021