Energy Dissipation and Particle Size Distribution of Granite under Different Incident Energies in SHPB Compression Tests

Abstract

To investigate energy dissipation and particle size distribution of rock under dynamic loads, a series of dynamic compression tests of granite specimens were conducted using a conventional split-Hopkinson pressure bar (SHPB) device with a high-speed camera. The experimental results show that the dissipated energy increases linearly with an increasing incident energy, following two different inclined paths connected by a critical incident energy, and the linear energy dissipation law in the dynamic compression test has been confirmed. This critical incident energy was found to be 0.29–0.33 MJ/m3. As the incident energy was smaller than the critical incident energy, the rock specimens remained unruptured after the impact. When the incident energy was greater than the critical incident energy, the rock specimens were ruptured or fragmented after the impact. In addition, the experimental results indicate that the dissipated energy and energy consumption ratio of a rock specimen, either unruptured or fragmented, increase with an increasing strain rate. Furthermore, it was found that fragment sizes at each mesh decrease with an increasing incident energy; that is, fragmentation becomes finer as incident energy increases.

Energy Requirement for Rock Breakage in Laboratory Experiments and Engineering Operations: A Review

“…Static compression tests with regular cylindrical specimens by Xie et al (2009) showed that as more energy was absorbed by a rock specimen, more and smaller fragments were produced from the specimen. Gong et al (2020) found that there was a critical absorbed energy of 0.36-0.41 MJ/m 3 for the granite tested in a Hopkinson pressure bar. As the absorbed energy by a rock specimen was smaller than this critical energy, the rock specimen would Zhang et al 2000Zhang et al , 2001 not be broken.…”

Effects of the Rock Bridge Ligament on Fracture and Energy Evolution of Preflawed Granite Exposed to Dynamic Loads

“…Li et al [17] proposed a test method for dynamic compression strength of rocks under prestatic load and measured the dynamic compression strength of sandstone under preload, and the results showed that the dynamic compression strength of the specimen under preload was higher than its compression strength under pure static load or pure dynamic load. Gong et al [18] found that the dissipation energy increased linearly with the increase of incident energy by conducting SHPB tests, and the linear energy dissipation law in dynamic compression tests was confirmed by connecting two different inclined paths by a critical incident energy. Yang et al [19] conducted impact compression tests on samples of red sandstone, gray sandstone, and granite, which are common in rock engineering, with different impact velocities.…”

Study on the Dynamic Mechanical Properties of Metamorphic Limestone under Impact Loading

“…In formula (7), it can be seen that the cumulative mass of any crushed body with a particle size smaller than r 0 in the crushed body can be expressed as follows:…”

“…Ping et al [2] used the SHPB test device to carry out impact tests on limestone at room temperature and between 100 °C and 800 °C to study the influence of temperature changes on the stress-strain curve and strength parameters. Zhang et al [3][4][5][6][7][8][9][10] used the improved Hopkinson test equipment to conduct conventional uniaxial impact tests on dolomite, granite, phyllite, and marble; the dynamic mechanical properties of ore and rock were studied from the stressstrain curve, failure morphology, energy distribution, and fractal dimension. Ma et al [11][12][13] conducted dynamic impact tests on artificially frozen sand and shale under active confining pressure, and the changes of stress-strain curves and strength parameters with confining pressure and strain rate were studied.…”