Discrete element modelling of elastic wave propagation through granular materials for laboratory shear plate tests

Masahide Otsubo, Troyee Dutta, Yuichiro Kawaguchi, Reiko Kuwano, Catherine O'Sullivan

Research output: Contribution to conferenceAbstract

Abstract

Measurement of elastic wave signals of granular materials is important to evaluate stiffness parameters including the small-strain stiffness. Granular soils consist of many soil grains and the overall response can be described as a result of interactions between particles in contacts, which can be modelled effectively using the discrete element method (DEM). In soil mechanics research, elastic wave signals are measured using bender elements or shear plates, both composed of piezo-electric elements. Despite the growing demand for accurate measurement of elastic wave signals both in the laboratory and in-situ, there is a lack of understanding on the link between macroscopic results and the particle-scale mechanics. DEM data can provide fundamental insight.

The aim of this contribution is to discuss how well DEM simulations can capture the responses observed in soil mechanics laboratory geophysics tests considering piezoelectric shear plates. The sensitivity of the dynamic wave signal to the shear plate size is assessed to inform the design of the shear plate configuration. Secondly, the effect of particle shape on stiffness anisotropy is discussed considering both isotropic and k0 stress states. Thirdly, the effect of including finer particles on the dynamic wave signals is investigated.
The DEM simulations in this contribution were performed using a modified version of the granular LAMMPS software where equivalent conditions with laboratory experiments using shear plates were considered. A simplified Hertz-Mindlin contact model was adopted. To assess the effect of particle shape on the stiffness anisotropy, spherical particles were rigidly clumped, and the simulation results were compared with laboratory geophysics tests using natural sands.
Original languageEnglish
Number of pages1
Publication statusPublished - 2019
Externally publishedYes
EventInternational Conference on Discrete Element Methods 2019 - Enschede, Netherlands
Duration: 21 Jul 201926 Jul 2019
Conference number: 8
https://mercurylab.co.uk/dem8/

Conference

ConferenceInternational Conference on Discrete Element Methods 2019
Abbreviated titleDEM 2019
CountryNetherlands
CityEnschede
Period21/07/1926/07/19
Internet address

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