Evolution of the Mesoscopic Parameters and Mechanical Properties of Granular Materials upon Loading

Abstract

Biaxial tests of granular materials under different lateral pressures were numerically simulated to study both the macromechanical behavior and evolution of mesoscopic parameters, including the coordination number, degree, clustering coefficient, and average shortest path length, which can provide information bridging mesoscale to macroscale of the mechanical properties of granular materials in a different and new way. The analysis results demonstrate that, with the increasing lateral pressure, there is a higher coordination number for denser granular material, and the coordination number of the samples eventually tends to the similar value at critical state with the same lateral pressure for different initial porosities; the distribution of the degree is very similar for samples with different initial porosities at critical state; the evolution of the clustering coefficients with axial strain is almost the same as that of the coordination number. At critical state, the clustering coefficients of all samples are almost identical, which means that the internal structures of samples with various initial porosities are similar; the average shortest path decreases with increasing lateral pressure and tends to be stable in the critical state. Additionally, the diameter of the contact network of granular material hardly changes at different lateral pressures at critical state.

Effect of particle shape on micro- and mesostructure evolution of granular assemblies under biaxial loading conditions

“…The properties of the network can be researched through the complex network method. And many of the recent developments of this method have taken place in sociology, biology, and in the field of granular materials [28,[43][44][45][46]. Studies have found that the 3 loops dominate the topologic structure at the mesoscale and 3 loops in a network is associated with frustrated rotations of particles and as such to stability [47,48].…”

The Material Deformation and Internal Structure Development of Granular Materials under Different Cyclic Loadings

“…Based on the concept of complex networks Tordesillas et al [20] analyzed the evolution of the contact networks. The contact network was particularly useful in describing particle interactions [21][22][23] which can quantify the changes in the internal structure of granular assemblies. Radjai et al [24,25] found that the contacts carrying above-and below-average normal forces have different effects on force transmission and work dissipation.…”

Analysis on Evolution of Force Chain and Contact Network of Non-Cohesive Soil

“…Although the study achievements of mesoscopic structure for cohesionless soil is quite rich, most of the research results only from a certain parameter of the mesoscopic structure (such as the fabric tensor [1], force chain [2]), with few studies on the evolution of contact networks in the process of loading. Recently, we have studied the evolution of mesostructure of soil samples from the perspective of complex network concepts [3,4,5], which can provide a new insight to investigate the physical mechanism of granular materials from meso to macro scale, and will be done here to explore the evolution of force chain and contact network of non-cohesive soil.…”