Wednesday  |  Allegheny  |  04:20 PM–04:40 PM

#13868, Time-Resolved Characterization of Impact Testing

Time-resolved impact studies were conducted to bridge the gap between materials property testing and full-scale ballistic experiments. The motivation is to characterize the projectile-target interaction at early time scales, which includes both the target and projectile response. Prior work has focused on demonstrating the utility of in situ diagnostic techniques for investigating the physics of failure of high-strength metallic and ceramic targets; however, less work has been done to experimentally quantify the projectile deformation. Digital image correlation has been identified as a promising technique to provide real-time, full-field characterization of the dynamic failure behavior during ballistic impact. In instances where the material response is multi-axial, DIC provides one of the only practical means of collecting full-field 3D data. Stereo DIC involves applying a speckle pattern to the target surface and tracking the deformation using two synchronized cameras. This allowed for the 3D reconstruction of displacement, velocity, and strain field histories. The focus of the current study is to understand the limitations and uncertainty of ultra-high-speed DIC for measuring high-rate deformation. A methodology is presented for implementing ultra-high-speed DIC in addition to complementary diagnostics such as multi-flash X-ray imaging, ultra-high-speed imaging, and photonic Doppler velocimetry (PDV).

Phillip Jannotti   U.S. Army Research Laboratory
Nicholas Lorenzo   U.S. Army Research Laboratory