Experimental research on the dynamic constringent characteristics and fractal properties of sandstone under impact loading

Abstract

Using the Split Hopkinson Pressure Bar (SHPB), a sequence of impact loading experiments were performed on sandstone to examine the dynamic constringent characteristics and crushing properties. The dynamic parameters, block size distribution, and energy characteristics of sandstone under various loading rates were obtained. The damaged sandstone was screened using a standard sieve and the particle size distribution curve conforming to the Rosin-Rammler distribution was discovered. On account of fractal theory, dynamic parameters, fractal dimension and energy characteristics of sandstone after splitting failure were constructed concerning the distribution of broken size. The results show that: the fragment size distribution of damaged sandstone complies with the geometric fractal law. As the loading rates increase, the fractal dimension of impacted fragments increases and the average fragment size decreases. The specimen’s energy dissipation density is a power function related to the fractal dimension, which is negatively associated with the average fragment size of the specimens. The research findings of this paper have necessary implications for rock-crushing engineering applications.

Keywords

• Fractal dimension
• Impact loading
• Loading rates
• Energy dissipation
• Rock mechanics