ガラスビーズを通過する応力波の伝播挙動の評価

抄録

To understand the mechanical properties of granular materials at high strain rates, it is necessary to understand stress wave propagation behavior between each particle (force chain) in granular materials. Packing density of granular materials affect the stress wave propagation between each particle. To examine the effect of packing density on stress wave propagation behavior, glass beads were used to control granular parameters such as particle size and particle shape. The purpose of this study was to measure the stress waves through glass beads by using the Split-Hopkinson Bar (SHB) test equipment and to clarify the effect of packing density on stress wave propagation behavior. As a specimen, glass beads were filled in a cylindrical container having a diameter of 30 mm, and two types of packing density (1.48 × 10³ kg / m³, 1.61 × 10³ kg / m³) were prepared. The test equipment consisted of a striker, an incident bar, the specimen, and a transmitted bar, and the stress waves generated when the launched striker had collided with the incident bar passed through the incident bar, the specimen, and the transmitted bar. This test was able to measure indirectly the stress waves transmitted through the specimen from the strains of the incident bar and the transmitted bar when the stress waves passed. As a result, stress-strain relationship and stress wave velocity in glass beads were confirmed. In addition, the results clarified the effect of packing density on stress wave propagation behavior in glass beads.