Visualizing the Fundamental Physics of Rapid Earth Penetration, using Transparent Soils

摘要

In this paper, rapid penetration into soils is studied using reduced scale tests. Refractive index-matched fused quartz, with geotechnical properties closely mimicking those of natural angular sands, is used as the target media. Penetration tests are performed by accelerating a conical rod into the soil target. Meso-scale kinematic interactions are probed during penetration by means of high speed imaging. An embedded plane of dyed fused quartz within the sample allows observations of soil deformation during the penetration. The images are analyzed using digital image correlation. The analyses suggest that soil velocity in the soil-projectile interaction zone decays rapidly with distance from the projectile, diminishing to zero within 4 diameters of the penetrator.