Low Velocity Penetration of Kaolin Clay

Penetration of rigid projectiles into compacted kaolin clay targets with carefully controlled properties is investigated. An examination of the experimental techniques for measuring the soil resistance to a penetrating projectile is presented. Procedures for construction of targets and determination of soil properties is described. Projectile diameter is varied from 1.5 to 3 in. (40 to 75 mm) and projectile weight is varied from 3 to 115 lbf (10 to 510 N). Six different nose shapes are tested. Impact velocity is varied from 30 to 300 fps (9.0 to 90 m/s). The effect of projectile and soil properties on the deceleration history of the projectile is demonstrated. Test results indicate that a critical velocity exists above which separation of the soil occurs during penetration. The critical velocity is a function of both soil and projectile properties.