Transparent Soils Wiki

Ballistics

Penetration of blunt and conical nose projectiles

Snapshots of penetration of blunt and conical nose projectiles at 4D and 6D penetration depths

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 spheres or conical rods 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.

 Incremental velocity fields

Incremental velocity fields resulting from DIC analysis at 4D and 6D penetration depths, for both conical and blunt projectile

(corresponding to Fig. 1 above)

The following video depicts penetration of spherical projectiles into transparent soils.    A video and still images of DIC conducted on successive images of a projectile penetrating transparent soils can be seen under the DIC tab under technologies.

 

Primary References

  • Omidvar, M., M. Iskander, and S. Bless (2016). Soil-projectile interactions during low velocity penetration. International Journal of Impact Engineering, doi: 10.1016/j.ijimpeng.2016.02.015, Elsevier [link]
  • Omidvar, M., J. Doreau Malioche, Z. Chen, M. Iskander, and S. Bless (2015). Visualizing kinematics of dynamic penetration in granular media using transparent soils. Geotechnical Testing Journal, Vol. 38, No. 5, doi: 10.1520/GTJ20140206, ASTM [link]
  •  Guzman, I., M. Iskander, S. Bless (2015). Observations of projectile penetration into a transparent soil. Mechanics research Communications, Vol. 70, Dec., pp. 4-11, doi:10.116.j.mechrescom.2015.08.008, Elsevier [link]
  • Guzman, I., M. Iskander, S. Bless, C. Qi (2014). Terminal depth of penetration of spherical projectiles in transparent granular media. Granular Matter, Vol. 16, No. 6, pp. 829-84, doi: 10.1007/s10035-014-0528-y [link]