Implementation of real contact behaviour in the DEM modelling of triaxial tests on railway ballast

Tolomeo, Mathias; McDowell, Glenn R.

Abstract

In the Discrete Element modelling of soils, the micromechanical behaviour at contacts has often been considered to have a minor influence on the macromechanical response, leaving basic theoretical models (e.g., Hertz) to describe the contact response in the normal direction. A realistic description of the contact response may be crucial especially when investigating small strain ranges. Recent experimental inter-particle loading tests on gravel suggest that the classic contact models fail to reproduce certain mechanical features, especially when roughness is significant. Here, some of these experimental observations, including a softer response than the Hertz model under loading in the normal direction, and plasticity on unloading, are implemented in a DEM model for the simulation of small strain tests on railway ballast. The influence of these features on small strain stiffness is highlighted. A micromechanical analysis is carried out to show how each of the contact-level features introduced affects the macroscopic response.

Citation

Tolomeo, M., & McDowell, G. R. (2022). Implementation of real contact behaviour in the DEM modelling of triaxial tests on railway ballast. Powder Technology, 412, Article 118021. https://doi.org/10.1016/j.powtec.2022.118021

• Journal Article Type: Article
• Acceptance Date: Oct 10, 2022
• Online Publication Date: Oct 18, 2022
• Publication Date: Nov 1, 2022
• Deposit Date: Oct 20, 2022
• Publicly Available Date: Oct 20, 2022
• Journal: Powder Technology
• Print ISSN: 0032-5910
• Electronic ISSN: 1873-328X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 412
• Article Number: 118021
• DOI: https://doi.org/10.1016/j.powtec.2022.118021
• Keywords: General Chemical Engineering
• Public URL: https://nottingham-repository.worktribe.com/output/12619133
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0032591022009020?via%3Dihub