The Texas A&M University Hypervelocity Impact Laboratory: A modern aeroballistic range facility

Abstract

Novel engineering materials and structures are increasingly designed for use in severe environments involving extreme transient variations in temperature and loading rates, chemically reactive flows, and other conditions. The Texas A&M University Hypervelocity Impact Laboratory (HVIL) enables unique ultrahigh-rate materials characterization, testing, and modeling capabilities by tightly integrating expertise in high-rate materials behavior, computational and polymer chemistry, and multi-physics multiscale numerical algorithm development, validation, and implementation. The HVIL provides a high-throughput test bed for development and tailoring of novel materials and structures to mitigate hypervelocity impacts (HVIs). A conventional, 12.7 mm, smooth bore, two-stage light gas gun (2SLGG) is being used as the aeroballistic range launcher to accelerate single and simultaneously launched projectiles to velocities in the range 1.5–7.0 km/s. The aeroballistic range is combined with conventional and innovative experimental, diagnostic, and modeling capabilities to create a unique HVI and hypersonic test bed. Ultrahigh-speed imaging (10M fps), ultrahigh-speed schlieren imaging, multi-angle imaging, digital particle tracking, flash x-ray radiography, nondestructive/destructive inspection, optical and scanning electron microscopy, and other techniques are being used to characterize HVIs and study interactions between hypersonic projectiles and suspended aerosolized particles. Additionally, an overview of 65 2SLGG facilities operational worldwide since 1990 is provided, which is the most comprehensive survey published to date. The HVIL aims to ( i) couple recent theoretical developments in shock physics with advances in numerical methods to perform HVI risk assessments of materials and structures, ( ii) characterize environmental effects (water, ice, dust, etc.) on hypersonic vehicles, and ( iii) address key high-rate materials and hypersonics research problems.

Evolution of dislocation substructures in metals via high-strain-rate nanoindentation

“…As such, there is a need to better understand the behavior of these materials in order to engineer the next generation of materials that will fulfill these applications. While machine-learning aided materials informatics promises to dramatically accelerate materials design and discovery ( 2 ), validating materials characterization and performance through standard high-strain-rate testing techniques, i.e., plate impact ( 3 ), split Hopkinson bar ( 4 – 6 ), and gas gun impact ( 7 ), still remains a bottleneck in the high-strain-rate materials design cycle due to the low throughput nature and high cost of these testing techniques. In this regard, high-strain-rate nanoindentation has recently emerged as a potentially useful high-throughput testing technique ( 8 ), but it remains unclear whether small-scale measurements adequately capture material deformation behavior at macroscopic scales ( 9 – 12 ).…”