Force-chain finder: A software tool for the recursive detection of force-chains in granular materials via minor principal stress

Abstract

Force transmission in granular media occurs through an inhomogeneous network of inter-particle contacts referred to as force-chains. A thorough understanding of the structure of these chains is indispensable for a better comprehension of the macroscopic signatures they generate. This paper introduces Force-Chain Finder (FCF), an open-source software tool designed for detecting force-chains in granular materials. Leveraging the stress tensor computed for each particle based on its interactions with neighbouring particles, the tool effectively identifies the magnitude and direction of the most compressive principal stress. Through a recursive traversal of particles and their neighbours, force-chains are robustly detected based on the alignment of the principal stress directions, which is decided by a parameter α (an angle in radians). The software provides a comprehensive suite of post-processing features, including the exportation of results in different formats, enabling detailed analysis of specific regions and dynamic phenomena. Additionally, the software facilitates the computation of statistical measures pertaining to chain size and population. By streamlining the identification and characterization of force-chains within discrete element method (DEM) simulations, this tool significantly enhances the efficiency and accuracy of force-chain analysis. Thus, the software promotes deeper insights into the behaviour of granular materials by enabling researchers to effortlessly detect and analyse force-chains. PROGRAM SUMMARYProgram Title: Force Chain Finder (FCF)CPC Library link to program files:https://doi.org/10.17632/33pkc4f63t.1Developer's repository link:https://github.com/Particles-Research/Force_Chain_Finder_Public/tree/mainLicensing provisions: GNU General Public License 3Programming Language: C++, PythonSupplementary material: Illustrative examplesNature of the Problem: FCF has been developed with the primary objective of efficiently and comprehensively detecting force networks that arise in Discrete Element Modelling (DEM) simulations of granular flow.Solution Method: The method is based on the work of “J. Peters, M. Muthuswamy, J. Wibowo, and A. Tordesillas, Characterization of force chains in granular material, Physical Review E 72, 041307 (2005)”. It utilizes the concept of minor principal stress to identify quasilinear chains, each consisting of at least three particles. However, significant algorithmic modifications have been implemented to enhance the accuracy of the procedure, enabling the detection of chain branching and merging.