Ted Zirkle, Ph.D.

Associate
Mechanical Engineering
Philadelphia
  • CV (English)
  • Contact Card

Dr. Zirkle’s background is in mechanical engineering with specialization in material deformation as well as fracture and fatigue. He has previously used advanced material models in concert with finite element analysis (FEA) to better understand experimentally observed fatigue processes, particularly in austenitic stainless steels (SS316). Specifically, he has investigated the failure of stainless steel structural components exposed to damaging hydrogen environments in nuclear energy applications. In addition to solid mechanics, Dr. Zirkle’s experience extends to the development of high throughput material characterization strategies leveraging techniques such as microindentation. Furthermore, He is proficient in the use of machine learning data analysis and is familiar with topology optimization strategies.

Prior to joining Exponent, Dr. Zirkle received his Ph.D. in Mechanical Engineering from the Georgia Institute of Technology. His research focused on better understanding the role that dislocation structures play in the plastic deformation of metals and alloys, specifically nickel and austenitic stainless steel. Dr. Zirkle developed a novel, multiscale crystal plasticity code and used it to investigate mesoscale dislocation processes, ultimately making connections to nanoscale simulations as well as macroscale experimental observations. This framework was used to directly study the role that hydrogen plays in modifying deformation behaviors near a fatigued crack. Dr. Zirkle translated these findings to the engineering component level, enabling more precise root cause failure analysis and permitting materials designers to account for complex load histories and damaging hydrogen environments. In addition to his graduate research, Dr. Zirkle has also spent time at the National Institute of Standards and Technology and Sandia National Laboratories, working on light-based surface roughness characterization and topology optimization, respectively.

Dr. Zirkle is proficient with the modeling software Ansys, Abaqus, and Dream3D as well as the coding languages MATLAB, Python, and Fortran.

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Mechanical Engineering, Georgia Institute of Technology (Georgia Tech), 2022
  • M.S., Mechanical Engineering, Georgia Institute of Technology (Georgia Tech), 2020
  • B.S., Mechanical Engineering, Walla Walla University, 2017
  • President’s Fellowship, Mechanical Engineering, Georgia Institute of Technology, 2017-2021

Publications

Zirkle T, McDowell DL. Modeling cyclic deformation of austenitic stainless steels at elevated temperatures using a physically-based mesoscale crystal plasticity framework. Materials Science and Engineering: A. 2022 Jan 14;832:142377.

Zirkle T, McDowell DL. Analysis of monotonic and cyclic crack tip plasticity for a stationary crack tip in a FCC crystal. Computational Materials Science. 2022 Feb 1;202:110954.

Zirkle T, Costello L, Zhu T, McDowell DL. Modeling Dislocation-Mediated Hydrogen Transport and Trapping in Face-Centered Cubic Metals. Journal of Engineering Materials and Technology. 2022 Jan 1;144(1).

Zirkle T, Zhu T, McDowell DL. Micromechanical crystal plasticity back stress evolution within FCC dislocation substructure. International Journal of Plasticity. 2021 Nov 1;146:103082.

Zirkle T, Costello L, McDowell DL. Crystal Plasticity Modeling of Hydrogen and Hydrogen-Related Defects in Initial Yield and Plastic Flow of Single-Crystal Stainless Steel 316L. Metallurgical and Materials Transactions A. 2021 Sep;52(9):3961-77.

Presentations

Zirkle T, Gu T, Anglin B, Geller C, McDowell DL. Crystal plasticity modeling of hydrogen concentration ahead of a crack tip in FCC steel. Oral presentation, 149th Annual Meeting & Exhibition of the Minerals, Metals & Materials Society (TMS), San Diego, CA, 2020.

Zirkle T, Locke B, Anglin B, Geller C, McDowell DL. Numerical methods applications in crystal plasticity finite element method. Poster presentation, Technical Meeting and Exhibition of Materials Science & Technology (MS&T), Portland, OR, 2019.

Prior Experience

Intern, QuesTek Innovations, January – May 2022

Visiting researcher, Sandia National Laboratories, June – August 2017

Summer research fellow, National Institute of Standards and Technology, June – August 2016

Additional Information

Peer Reviewer

International Journal of Fatigue

Journal of Engineering Materials and Technology

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Mechanical Engineering, Georgia Institute of Technology (Georgia Tech), 2022
  • M.S., Mechanical Engineering, Georgia Institute of Technology (Georgia Tech), 2020
  • B.S., Mechanical Engineering, Walla Walla University, 2017
  • President’s Fellowship, Mechanical Engineering, Georgia Institute of Technology, 2017-2021