Stress wave propagation characteristics and energy dissipation effects in sandy soil

To investigate the energy attenuation law and propagation velocity of stress waves in sandy soil material, this paper focuses on the dynamic response of stress waves in a specimen under both single impact and repetitive impact conditions. The improved split Hopkinson pressure bar (SHPB) system is utilized for this purpose. The results reveal that the length of the specimen follows an exponential function relationship with the attenuation of peak stress. As the length of the specimen increases from 40 mm to 240 mm, the attenuation rate of peak stress increases from 26.3–99.0%. The velocity of peak stress decreases with the increase in specimen length, indicating a correlation between these two factors. Furthermore, the impact test results show that the number of impacts and the density of the specimen affect the attenuation of the stress wave. As the number of impacts increases, the density of the specimen also increases, resulting in a gradual decrease in the degree of stress wave attenuation. When the density increases from 1.60 g·cm ^− 3 to 2.29 g·cm ^− 3 , the attenuation of the stress wave decreases by 17.0%, and the energy absorption density increases from 0.241 MJ·m ^− 3 to 1.172 MJ·m ^− 3 , representing a 386.3% increase. Additionally, the study finds that the energy absorption efficiency decreases with the increase in the number of impacts at the same stress level. However, after two impacts, the energy absorption efficiency approaches a steady state. At the same strain level, the energy absorption efficiency remains consistent, indicating the material's energy dissipation characteristics.