Influence of particle packing structure on sound velocity

作     者：赵闯 李成波 鲍琳 Chuang Zhao;Cheng-Bo Li;Lin Bao

作者机构：College of PhysicsGuizhou University College of Mathematics and PhysicsAnyang Institute of Technology 

出 版 物：《Chinese Physics B》 (中国物理B（英文版）)

年 卷 期：2018年第27卷第10期

页      面：386-394页

核心收录：

学科分类：07[理学] 070206[理学-声学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0704[理学-天文学] 0702[理学-物理学] 

基　　金：Project supported by the National Natural Science Foundation of China(Grant No.11547009) the Young Scientists Fund of the National Natural Science Foundation of China(Grant No.11602062) the Natural Science Foundation of Guizhou Province,China(Grant No.2012/2166) the Research Foundation of Guizhou University for Talent Introduction,China(Grant No.2011/02) 

主　　题：discrete element method acoustic propagation packing structure stiffness tensor 

摘      要：The anisotropy in the particle systems of different packing structures affects the sound velocity. The acoustic propagation process in four kinds of packing structures（denoted as S45, H60, S90, and D） of two-dimensional granular system is simulated by the discrete element method. The velocity vtof obtained by the time of flight method and the velocity vc obtained from the stiffness tensor of the system are compared. Different sound velocities reflect various packing structures and force distributions within the system. The compression wave velocities of H60 and S90 are nearly the same, and transmit faster than that of D packing structure, while the sound velocity of S45 is the smallest. The shear wave velocities of S45 and H60 are nearly the same, and transmit faster than that of D packing structure. The compression wave velocity is sensitive to the volume fraction of the structure, however, the shear wave velocity is more sensitive to the geometrical structure itself. As the normal stress p is larger than 1 MPa, vtof and vc are almost equal, and the stiffness tensors of various structures explain the difference of sound velocities. When the normal stress is less than 1 MPa, with the coordination number unchanged, the law vtof ∝ p^1/4 still exists. This demonstrates that apart from different power laws between force and deformation as well as the change of the coordination number under different stresses, there are other complicated causes of vtof∝ p^1/4, and an explanation of the deviation from vtof ∝ p^1/6 is given from the perspective of dissipation.