3D DEM Simulations and Experiments on Spherical Impactor Penetrating into the Elongated Particles.

Area of Science:

• Granular Mechanics
• Particle Physics
• Computational Physics

Background:

• Understanding granular material behavior under dynamic loading is crucial for various engineering applications.
• Particle shape and inter-particle forces significantly influence macroscopic granular responses.

Purpose of the Study:

• To investigate the effects of particle characteristics and impactor properties on granular bed penetration dynamics.
• To analyze the influence of particle length, friction, and configuration on impactor penetration depth, ejecta mass, and solid volume fraction.

Main Methods:

• Three-dimensional discrete element method (DEM) simulations were employed.
• Simulations were validated against experimental data for particle mass before and after impactor penetration.

Main Results:

• Impactor penetration depth showed a negative correlation with particle length (Lp) and solid volume fraction.
• A reduced friction coefficient resulted in increased impactor penetration depth and greater particle ejection.
• For elongated particles (Lp = 10 mm), penetration depth was negatively correlated with the order parameter and solid volume fraction.

Conclusions:

• Particle length and friction coefficient are key parameters governing impactor penetration in granular media.
• Particle shape and packing density (solid volume fraction) play critical roles in granular bed resistance to penetration.