Analysis of bender element test interpretation using the discrete element method

J. O’Donovan (Lead / Corresponding author), C. O’Sullivan, G. Marketos, D. Muir Wood

    Research output: Contribution to journalArticle

    15 Citations (Scopus)

    Abstract

    While bender element testing is now well-established as a laboratory technique to determine soil stiffness, a robust technique to interpret the data remains elusive. A discrete element method (DEM) model of a face-centred cubic packing of uniform spheres was created to simulate bender element tests to investigate this test from a fundamental perspective. During the DEM simulations transmitter and receiver signals were recorded, analogous to the data available in laboratory tests, and these macro-scale data were supplemented with particle scale measurements (forces, stresses and displacements). A range of approaches previously applied in experimental and numerical studies were used to analyse the resulting data in both the time and frequency domains. The shortcomings in these approaches are clear from the differences in the resultant shear stiffness values and the frequency-dependent nature of the values. The particle-scale data enabled visualization of the passage of the wave through the sample, and it was found not to be possible to precisely link the arrival of the shear wave at the receiver and any of the previously proposed characteristic points along the signal recorded at the receiver. The most reliable determination of the shear wave velocity was obtained by applying a two-dimensional fast Fourier transform (2D FFT) to the data describing the velocity of the particles lying between the transmitter and receiver elements. Use of the DEM model and this 2D FFT approach facilitated the sensitivity of the system response to small variations in the interparticle force–displacement law (the contact model) to be established.

    Original languageEnglish
    Pages (from-to)197-216
    Number of pages20
    JournalGranular Matter
    Volume17
    Issue number2
    DOIs
    Publication statusPublished - Apr 2015

    Fingerprint

    Finite difference method
    Fast Fourier transforms
    receivers
    Shear waves
    Transmitters
    fast Fourier transformations
    Stiffness
    Signal receivers
    transmitters
    S waves
    stiffness
    Data visualization
    Force measurement
    scientific visualization
    Macros
    arrivals
    Soils
    soils
    Testing
    shear

    Keywords

    • Contact model
    • DEM
    • Small-strain stiffness
    • Wave propagation

    Cite this

    O’Donovan, J. ; O’Sullivan, C. ; Marketos, G. ; Muir Wood, D. / Analysis of bender element test interpretation using the discrete element method. In: Granular Matter. 2015 ; Vol. 17, No. 2. pp. 197-216.
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    Analysis of bender element test interpretation using the discrete element method. / O’Donovan, J. (Lead / Corresponding author); O’Sullivan, C.; Marketos, G.; Muir Wood, D.

    In: Granular Matter, Vol. 17, No. 2, 04.2015, p. 197-216.

    Research output: Contribution to journalArticle

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