Dynamic characteristics of sphere impact into wet granular materials considering suction

Understanding the impact and penetration characteristics of non-homogeneous granular material systems is of great significance for various research work. In this study, a series of experiments are conducted to investigate the impact and penetration processes of sand and glass beads, two granular materials with different moisture contents. The ultra-high-speed camera is used to capture the dynamic response of the projectile, while the impact force during impact and penetration is recorded by miniature load cells arranged underneath the container. The results show that the dynamic response of the projectile differs significantly for different types of granular materials with different moisture contents. The comparison between wet and dry granular materials reveals that the terminal penetration depth and the duration of the collision are much less for wet granular materials than for dry ones, and the effect of moisture content on the terminal penetration depth of the projectile is discussed. Assuming that the presence of moisture has no effect on the inertial force term, a modified motion equation is proposed taking into account the suction of wet granular materials.