講演情報
[PPS05-P05]Longitudinal wave propagation in granular layer with various particle sizes
*櫻井 哲志1、中村 昭子1 (1.国立大学法人神戸大学大学院理学研究科)
キーワード：
小惑星
Wave velocity is one of the key parameters for understanding impact processes on planetary bodies. Because rubble-pile asteroids consist of rocks of various sizes, ranging from meter-scale boulders to millimeter- and centimeter-scale particles, investigating and characterizing the wave velocities of granular layers with different particle sizes is essential for understanding impact processes on such asteroids. However, the dependence of wave velocity on particle size appears to remain inconclusive.
We measured the longitudinal wave velocity of glass-bead layers with various particle sizes using the pulse transmission method. The particle sizes of the glass-bead layers used in our study were 0.1, 1, 3, and 10 mm, with a layer thickness of 24–27 mm. To investigate the effect of layer thickness on the longitudinal wave velocity, additional measurements were conducted with layer thicknesses of 4–5 mm for the 0.1- and 1-mm beads, and 8–9 mm for the 3-mm beads. Longitudinal waves could not be detected under unconfined conditions, so all measurements were performed under a confining pressure of 0.1 MPa. The results showed that the longitudinal wave velocity increased with increasing particle size, consistent with previous studies (Zimmer, 2003; Teramoto and Yano, 2005). Additionally, the longitudinal wave velocity was found to depend on the propagation distance normalized by the particle size.
We measured the longitudinal wave velocity of glass-bead layers with various particle sizes using the pulse transmission method. The particle sizes of the glass-bead layers used in our study were 0.1, 1, 3, and 10 mm, with a layer thickness of 24–27 mm. To investigate the effect of layer thickness on the longitudinal wave velocity, additional measurements were conducted with layer thicknesses of 4–5 mm for the 0.1- and 1-mm beads, and 8–9 mm for the 3-mm beads. Longitudinal waves could not be detected under unconfined conditions, so all measurements were performed under a confining pressure of 0.1 MPa. The results showed that the longitudinal wave velocity increased with increasing particle size, consistent with previous studies (Zimmer, 2003; Teramoto and Yano, 2005). Additionally, the longitudinal wave velocity was found to depend on the propagation distance normalized by the particle size.