Advanced science.  Applied technology.


Penetration Mechanics Short Course Instructors


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 second volume of the Report of the space shuttle Columbia Accident Investigation Board. In 2004 he was included in Popular Science’s third annual list of "Brilliant 10" scientists. 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 mathematics and mechanical engineering 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 the International Ballistics Society.

Charles E. Anderson, Jr.

B.S. from Virginia Polytechnic Institute; M.S. and Ph.D. from Rensselaer Polytechnic Institute

Dr. Anderson retired from Southwest Research Institute in May 2015, but remains active in multi-disciplinary research investigations of the dynamic response of materials and structures. He has over 40 years of experience in numerical simulations of explosive-metal interactions and impact mechanics, using numerical simulations for fundamental and applied studies. Dr. Anderson is recognized for his leadership in combining numerical simulations with experimental data to develop advanced models of the response of materials to shock, impact, and penetration. He has been the organizing chair and technical chair for a number of international conferences/symposia. Dr. Anderson continues to serve on Government advisory boards dealing with issues in computational mechanics, penetration mechanics, and the response of materials at high loading rates, areas in which he has published extensively. He is an Associate Editor for the International Journal of Impact Engineering, a fellow of the American Physical Society, and a Ballistic Science Fellow of the International Ballistics Society. In 2000, Dr. Anderson received the Distinguished Scientist Award from the Hypervelocity Impact Society for his contributions to penetration mechanics, numerical simulations of penetration mechanics, and modeling dynamic material response.

James S. Wilbeck

B.S., M.S., and Ph.D. in Engineering from Texas A&M University

Dr. Wilbeck has 40 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 rockets, artillery and mortar to bullet impact. Dr. Wilbeck has authored more than 50 reports and papers concerning studies of impact, scale modeling, and material characterization.

Sidney Chocron

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 almost 15 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 70 technical papers/reports. After co-chairing the International Ballistics Symposium in Tarragona, Spain, he became a member of the International Ballistics Committee in April 2007. Dr. Chocron teaches portions of Advanced Solid Mechanics and Mechanical Behavior of Materials at the University of Texas at San Antonio, and assists as referee for five international journals.

Timothy J. Holmquist

B.S. and M.S. in Civil Engineering from University of Minnesota

Mr. Holmquist has over 30 years of experience in penetration mechanics, warhead design, high strain-rate material response, material model development and hydrocode analysis. His primary focus has been understanding high strain-rate material response for ballistic impact applications. He is the co-author of the JH-1, JH-2 and JHB constitutive models for brittle materials, the HJ model for glass, and the HJC model for concrete. He has also been involved in the development and application of the EPIC hydrocode and is a co-author of the latest version, EPIC2016. Mr. Holmquist has co-authored more than 70 technical publications concerning high-velocity impact and high-rate material behavior. He is the past president and board member of the Hypervelocity Impact Society.

Scott A. Mullin

B.S. from The University of Texas at El Paso; and M.S. from California Institute of Technology

Mr. Mullin is the Manager of the Ballistics and Explosives Engineering Section, and has more than 20 years experience in impact phenomenology, penetration mechanics, explosive and ballistic sciences, scale modeling, and instrumentation. He has served as project manager and principle 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 during his tenure at SwRI, 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.