James D. Walker
B.S., M.A., and Ph.D. from The University of Utah
Dr. Walker is Director of the Engineering Dynamics Department of SwRI, where he oversees and manages a multi-disciplinary effort to investigate the dynamic response of materials and structures. His research is in wave propagation, plasticity, penetration mechanics, blast loading, and the dynamic response, fracture and failure of materials. Typically his work includes and combines large scale numerical simulations (finite element, finite volume, spectral), analytical techniques, and experiments. He is a developer of the Walker-Anderson penetration model. Dr. Walker’s work includes applications in armors and blast protection for ground vehicles, naval vessels, and spacecraft. He authored the chapter "Impact Modeling" in the Report of the space shuttle Columbia Accident Investigation Board. In 2004 he was included in Popular Science’s "Brilliant 10" scientists list. He was awarded the 2005 ASME Holley Medal and the 2014 TAMEST O’Donnell Award in Technology Innovation. Dr. Walker was an AIAA Distinguished Lecturer. He has taught mechanical engineering and mathematics at the graduate level at the University of Texas at San Antonio. He is a past president of the Hypervelocity Impact Society. He is a Fellow of AIAA, ASME, and a Ballistic Science Fellow of the International Ballistics Society.
James S. Wilbeck
B.S., M.S., and Ph.D. in Engineering from Texas A&M University
Dr. Wilbeck has 46 years of experience in the analytical and experimental study of impact mechanics, with emphasis on the development of simplified analytical and numerical models. Over the years, Dr. Wilbeck has applied his background in wave propagation, material characterization, and impact mechanics to the study of fragment and hit-to-kill lethality of missile systems, shaped charge and EFP development, long rod penetration, and the response of high explosives to impact. He is currently involved in both the testing and analysis of the response of hypersonic and hypervelocity vehicles to impact. Dr. Wilbeck has authored more than 50 reports and papers concerning studies of impact, scale modeling, and material characterization.
M.S. and Ph.D. from Polytechnic University of Madrid
Dr. Chocron has experience in low and high strain rate constitutive models for ceramics, metals and foams applied to analytical and numerical computations. An emphasis of his research has been the fundamental study of ballistic fabrics (woven and nonwoven) and composites. Dr. Chocron has been active in the field for more than 25 years, most of the time in Madrid and San Antonio but performing occasional research in other centers such as University of Oxford (England), US Army Natick (Massachusetts), Technion (Israel), and UT-Austin (Texas). Dr. Chocron has coauthored close to 50 technical papers in peer-reviewed journals and 100 full papers in proceedings. After co-chairing the International Ballistics Symposium in Tarragona, Spain, he joined the International Ballistics Society in April 2007 and became Treasurer and Secretary. Since 2017 he is the President of the Society. Dr. Chocron teaches as Adjoint Professor at the University of Texas at San Antonio, where he teaches continuum mechanics and other classes, and supervises a Ph.D. candidate.
Stephen R. Beissel
B.S. from The University of Washington; M.S. and Ph.D. from Northwestern University
Dr. Beissel has more than 25 years of experience as a developer of finite-element software for computational solid mechanics. His primary role has been co-developer of the EPIC code, which models the dynamic large deformations and failure of solid materials subjected to the extreme loads from high-velocity impacts and explosive detonations, which is widely used throughout the DoD and the defense industry for the design of weapon systems and armor. Dr. Beissel has developed many of EPIC’s algorithms. Included among these are the formulations of elements, such as the cohesive elements for modeling failure along material interfaces, the shell and beam elements for modeling structural response, and the higher-order elements for modeling wave propagation. He recently developed new algorithms to enforce contact boundary conditions between higher-order elements, and to integrate the governing equations in time by implicit schemes for longer simulated durations. Dr. Beissel has also contributed algorithms that model the ballistic responses of materials, including ceramics, fabrics, and fiber-reinforced composites. He has improved the computational efficiency of EPIC by instrumenting the code with MPI algorithms for inter-processor communications, enabling parallel computations on both shared and distributed memory computer architectures. In addition to developing software, Dr. Beissel has been an active participant in the computational mechanics community, having contributed over 30 technical papers and frequently presenting his research at symposia.
Alexander J. Carpenter
B.S., M.S. and Ph.D. from The University of Texas at Austin
Dr. Carpenter is a Lead Engineer in the Engineering Dynamics Department at Southwest Research Institute. He performs high-rate numerical simulations, particularly of ballistic and blast events, using various Lagrangian finite element solvers and Eulerian hydrocodes. He analyzes material characterization data obtained under a variety of conditions and stress states (e.g., tension, compression, shear, plate impact) to fit both material models and equations of state for use in simulation codes. His interests include modeling of a variety of engineering materials including metals, ceramics, foams, soils, and composites. Dr. Carpenter has created novel material models for reproducing the directional failure and subsequent response of metals, ceramics, and composites which have been implemented in various numerical solvers for use in complex impact-loading problems. He has co-authored twelve refereed journal articles and over thirty conference papers.
Scott A. Mullin
B.S. from The University of Texas at El Paso; and M.S. from California Institute of Technology
Mr. Mullin is a Technical Advisor for Southwest Research Institute. Formerly, he was the Manager of the SwRI’s Ballistics and Explosives Engineering Section. He has more than 35 years of experience in impact phenomenology, penetration mechanics, explosive and ballistic sciences, scale modeling, and instrumentation. He has served as project manager and principal investigator on over 50 experimental programs at the SwRI ballistic range, where he has been responsible for design, instrumentation, data gathering, and analysis. Mr. Mullin has been actively involved in scale (similitude) modeling, applying the technique in many diverse areas of experimental design and data analysis. He is also an instructor in the SwRI short course, Scale Modeling in Engineering Dynamics.
James T. Mathis
B.S. and M.S. in Mechanical Engineering from The University of Texas at San Antonio
Mr. Mathis is a Staff Engineer in the Ballistics and Explosives Section at Southwest Research Institute where he manages and supports experimental and computational programs involving dynamic response due to explosive blast and ballistic impact. His primary area of focus is high-speed diagnostics and customized instrumentation for dynamic events to support collection of high quality data for analysis of impact events and validation of computational models. He utilizes his knowledge and experience in diagnostics for the proper selection, design, and application of transducers, data acquisition equipment, and post processing tools. In addition, Mr. Mathis conducts full-scale bird strike tests to develop bird-impact-resistant aerospace structures and for FAA/EASA certification tests.
Donald J. Grosch
B.S. in Mechanical Engineering from The University of Texas at San Antonio
Mr. Grosch is the Manager of the Ballistics and Explosives Section. He has worked at SwRI for over
30 years. His work is mostly experimental, managing technical programs that utilize all of the Department’s Ballistics and Explosive Ranges. He conducts hypervelocity impacts and other hypersonics-related research using SwRI’s two-stage light gas gun facilities. He conducts small arms ballistic tests and large caliber ballistic experiments with guns up to 50mm. Mr. Grosch also conducts explosive experiments to include the use of linear and conventional shaped charges, 155-mm artillery shells, 500-pound Mk-82 general purpose bombs, explosively formed projectiles (EFP’s), and large bare explosive charges up to 1250-pounds. Over the years, his work has supported programs with the US Army, Navy, Air Force, DARPA, NASA, the Department of Energy, and commercial firms. Mr. Grosch was the project manager of the Columbia Accident Investigation program at SwRI, in which the cause of the Space Shuttle Columbia disaster was proven to be a foam impact during launch that resulted in a hole in the wing leading edge. Mr. Grosch is a past chairman of the Aeroballistics Range Association and maintains an active role in that organization.
Or call Janet Banda at +1 210 522 2386.