中国物理B ›› 2018, Vol. 27 ›› Issue (10): 104501-104501.doi: 10.1088/1674-1056/27/10/104501

• ELECTROMAGNETISM, OPTICS, ACOUSTICS, HEAT TRANSFER, CLASSICAL MECHANICS, AND FLUID DYNAMICS • 上一篇    下一篇

Influence of particle packing structure on sound velocity

Chuang Zhao(赵闯), Cheng-Bo Li(李成波), Lin Bao(鲍琳)   

  1. 1 College of Physics, Guizhou University, Guiyang 550025, China;
    2 College of Mathematics and Physics, Anyang Institute of Technology, Anyang 455000, China
  • 收稿日期:2018-04-10 修回日期:2018-06-13 出版日期:2018-10-05 发布日期:2018-10-05
  • 通讯作者: Chuang Zhao E-mail:1508868030@qq.com
  • 基金资助:

    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), and the Research Foundation of Guizhou University for Talent Introduction, China (Grant No. 2011/02).

Influence of particle packing structure on sound velocity

Chuang Zhao(赵闯)1, Cheng-Bo Li(李成波)2, Lin Bao(鲍琳)1   

  1. 1 College of Physics, Guizhou University, Guiyang 550025, China;
    2 College of Mathematics and Physics, Anyang Institute of Technology, Anyang 455000, China
  • Received:2018-04-10 Revised:2018-06-13 Online:2018-10-05 Published:2018-10-05
  • Contact: Chuang Zhao E-mail:1508868030@qq.com
  • Supported by:

    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), and the Research Foundation of Guizhou University for Talent Introduction, China (Grant No. 2011/02).

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 vtofp1/4 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 vtofp1/4, and an explanation of the deviation from vtofp1/6 is given from the perspective of dissipation.

关键词: discrete element method, acoustic propagation, packing structure, stiffness tensor

Abstract:

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 vtofp1/4 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 vtofp1/4, and an explanation of the deviation from vtofp1/6 is given from the perspective of dissipation.

Key words: discrete element method, acoustic propagation, packing structure, stiffness tensor

中图分类号:  (Granular systems)

  • 45.70.-n
46.40.Cd (Mechanical wave propagation (including diffraction, scattering, and dispersion)) 83.80.Fg (Granular solids)