Influence of particle size on vertical plate penetration into dense cohesionless granular materials (large-scale DEM simulation using real particle size)

Abstract

The influence of the particle size on the vertical plate penetration into dense cohesionless granular materials was numerically investigated. Simulations were performed in quasi-two-dimensional conditions by changing the mean particle diameters d 50 but maintaining the plate thickness B from B/d 50 = 63-2.6. The initial bulk packing fraction was kept high, irrespective of the particle size. In the smallest particle size case (B/d 50 = 63), the size ratio reached almost the same level as that in the laboratory experiments using natural sand particles. The results demonstrated that the mean penetration resistance force acting on the plate tip surface increases with a decrease of B/d 50 , while the tangential force acting on the side surfaces does not change with B/d 50 . Tip resistances increase linearly with the penetration depth, while the tangential resistances increase with the square of the depth regardless of B/d 50 . The behavior of the resistance fluctuations changes qualitatively between B/d 50 = 31 and 21. For all cases, we confirmed the formation of a wedge-shaped flow with a high forward velocity in front of the plate tip. The wedge flow width was larger than the plate thickness by almost a mean particle diameter, and was responsible for the increase in the mean resistance depending on the particle size. For the large B/d 50 cases only, the resistance exhibited quasiperiodic fluctuations, which was attributable to the intermittent nucleation and disappearance of the shear bands. Moreover, we investigated the dependence of B/d 50 on the band evolutions by analyzing the band thickness.

Forces and flow induced by a moving intruder in a granular packing: coarse-graining and DEM simulations versus experiments

“…One critical issue is to consider the effect of non-homogeneous boundary conditions. While many papers deal with the penetration of an intruder in a packing [23,24,44], to our best knowledge there are very few that deal with its pull-off [27]. Note that these are far to be symmetrical configurations which confirm the difference of behavior with our configuration and show the need for a specific study.…”

“…The observed decrease in particle solid fraction can be attributed to a global dilatancy (Fig. 9) [44,45,51]. Fig.…”

“…we clearly see a good agreement between the experimental and numerical general trends. The origin of these fluctuations was studied by [44] for the penetration a cylindrical punch into a dense cohesive granular bed and by Gravish et al [45] for an intruder moved horizontally. Both studies attribute the origin of the fluctuations to the phenomenon of packing dilatancy which is known to strongly depends on the initial packing fraction compared to its critical value in the steady state [46].…”

Advances in Projectile Penetration Mechanism in Soil Media

“…However, at impact speeds of approximately 1.3 km/s, the depth of penetration began to decrease due to increasing levels of stress and temperature caused by friction between projectile and the target material. A review of past research indicates that considerable experimental work has been done on the impact of projectiles on non-cohesive soil or granular material targets [14,124]. However, there are scant experimental studies available on the impact of projectiles on cohesive targets [125,126].…”

Comparative Study on Estimation Methods of Dynamic Resistance Using Dynamic Cone Penetrometer

“…Therefore, the effect of integration interval on dynamic resistance estimation is significant, regardless of the integration methods, and the force-based dynamic resistance estimated for longer intervals would be a promising approach for soil strength characterization. Considering that previous studies simulated the characteristics and behavior of granular materials under similar penetration condition [ 27 , 28 ], further study on the simulation of dynamic penetration in the granular material may be meaningful to better understand the dynamic resistances estimated by using IDCP .…”