We propose a simple elastic-plastic contact model by considering the interaction of two spheres in the normal direction, for use in discrete element method (DEM) simulations of geomaterials. This model has been developed by using the finite element method (FEM) and nonlinear fitting methods, in the form of power-law relation of the dimensionless normal force and displacement. Only four parameters are needed for each loading-unloading contact process between two spheres, which are relevant to material properties evaluated by FEM simulations. Within the given range of material properties, those four parameters can be quickly accessed by interpolating the data appended or by regression functions supplied. Instead of the Von Mises (V-M) yield criterion, the Drucker-Prager (D-P) criterion is used to describe the yield behavior of contacting spheres in this model. The D-P criterion takes the effects of confining pressure, the intermediate principal stress, and strain rate into consideration; thus, this model can be used for DEM simulation of geomaterials as well as other granular materials with pressure sensitivity.


Materials Science and Engineering


Financial support from the National Natural Science Foundation of China (no. 51308474) and the Fundamental Research Funds for the Central Universities (no. 2682017CX005).

Keywords and Phrases

Elastoplasticity; Finite Difference Method; Spheres; Strain Rate; Unloading, Confining Pressures; Elastic-Plastic Contact; Granular Geomaterials; Intermediate Principal Stress; Nonlinear Fitting Method; Power Law Relation; Pressure Sensitivities; Regression Function, Finite Element Method

International Standard Serial Number (ISSN)

1687-8434; 1687-8442

Document Type

Article - Journal

Document Version

Final Version

File Type





© 2018 The Authors, All rights reserved.

Creative Commons Licensing

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.

Publication Date

01 Jan 2018