Experimental study on crushing characteristics and energy absorption effect of silica sand under dynamic loading

This study investigates the response characteristics of silica sand under dynamic loading, employing a modified split Hopkinson pressure bar (SHPB) to gain insights into its crushing behavior and energy absorption properties. Four distinct grain size (2.5–5.0 mm, 1.25–2.50 mm, 0.60–1.25 mm, and <0.3 mm) were analyzed, with results demonstrating that the dynamic stress-strain behavior of silica sand is affected by both grain size and strain rate. The deformation process of silica sand is categorized into four stages: elastic, yielding, plastic and unloading. Plastic compaction is dominant during the yielding stage, whereas crushing compaction prevails in the plastic stage. The relative breakage of particles shows a positive correlation with both strain rate and effective particle size, and an inverse correlation with fractal dimension. The impact of particle size on energy absorption efficiency is influenced by factors such as mineral composition, particle size, and differentiation degree. Under identical stress levels, larger particle sizes demonstrate greater energy absorption efficiency; similarly, under identical loading strain rates, larger particles exhibit lower peak stress. To improve sand's energy absorption efficiency and reduce required loading levels, sand with larger particle sizes is recommended.