An Overview of Theoretical and Experimental Techniques for Material Behavior Characterization in Shock Physics

Abstract

Shock Physics that deals with material behavior at a very high strain rate (in the order of material propagation speed) reveals more and more its importance in engineering applications (automotive, defense, aeronautic, space, energy, etc.), geophysics (earth’s behavior, asteroid impacts) or astrophysics (planets and stars behavior). Nowadays, this term is used more often when classical high-speed dynamics reach their physical limits. After a short introduction to shock physics, an application to lightweight armor is used to illustrate the importance of coupling tuned experiments with simulations for dynamic material studies: In fact, lightweight armors of soldiers are in constant evolution to optimize protection efficiency. In this area, more and more complex simulations are investigated with compound structures including polymeric foam, composite, metal, and ceramic. Even if numerical capabilities are in perpetual evolution, there is a constant need of improving the knowledge of individual material response in the strain, strain rate regime closed to the threat. Collecting parameters for Equation Of State (EOS), strength and/or rupture models to fit material models is thus mandatory to ensure reliable numerical investigations. Since 2015, THIOT INGENIERIE Shock Physics Laboratory has been selected by the French Ministry Of Defense (MOD) Land Systems to perform materials characterization in three main families of ballistic materials. Parallel to those tasks, in-house simulations done by the dynamic material department have shown a very good agreement with validation tests based on the dynamic material characterizations. A coupled approach between laboratory experiments and numerical simulations has shown its relevance with ceramic, [1], an Ultra High Molecular Weight Polyethylene composite (UHMWPE) [2] and a polymeric foam [3]. For all those materials, the BBA methodology has been used to calibrate EOS, strength, and damage models by conducting a step-by-step procedure with a dual approach, mixing together experimental tests and numerical works simultaneously.