Recherche

Résultats de recherche

  • 1. Effect of Topology on Transient Dynamic and Shock Response of Polymeric Lattice Structures

    La description:
    Architected cellular materials, such as lattice structures, offer potential for tunable mechanical properties for dynamic applications of energy absorption and impact mitigation. In this work, the static and dynamic behavior of polymeric lattice structures was investigated through experiments on octet-truss, Kelvin, and cubic topologies with relative densities around 8%. Dynamic testing was conducted via direct impact experiments (25–70 m/s) with high-speed imaging coupled with digital image correlation and a polycarbonate Hopkinson pressure bar. Mechanical properties such as elastic wave speed, deformation modes, failure properties, particle velocities, and stress histories were extracted from experimental results. At low impact velocities, a transient dynamic response was observed which was composed of a compaction front initiating at the impact surface and additional deformation bands whose characteristics matched low strain-rate behavior. For higher impact velocities, shock analysis was carried out using compaction wave velocity and Eulerian Rankine–Hugoniot jump conditions with parameters determined from full-field measurements.
    Mot-clé:
    Failure, Digital image correlation, Transient dynamic, Shock, Lattice structure, and Compaction
    Assujettir:
    Applied Science and Engineering
    Créateur:
    Weeks, J. S. and Ravichandran, Guruswami
    Owner:
    n.sakthivel@jioinstitute.edu.in
    Éditeur:
    Springer Nature
    Emplacement:
    Switzerland
    La langue:
    English
    Date de téléchargement:
    21-03-2023
    Date modifiée:
    21-03-2023
    date créée:
    01-12-2022
    Rights Statement Tesim:
    In Copyright
    License Tesim:
    All rights reserved
    Resource Type:
    Article
    Identificateur:
    10.1007/s40870-022-00359-2

  • 2. Mesoscale shock structure in particulate composites

    La description:
    Multiscale experiments in heterogeneous materials and the knowledge of their physics under shock compression are limited. This study examines the multiscale shock response of particulate composites comprised of soda-lime glass particles in a PMMA matrix using full-field high speed digital image correlation (DIC) for the first time. Normal plate impact experiments, and complementary numerical simulations, are conducted at stresses ranging from to elucidate the mesoscale mechanisms responsible for the distinct shock structure observed in particulate composites. The particle velocity from the macroscopic measurement at continuum scale shows a relatively smooth velocity profile, with shock thickness decreasing with an increase in shock stress, and the composite exhibits strain rate scaling as the second power of the shock stress. In contrast, the mesoscopic response was highly heterogeneous, which led to a rough shock front and the formation of a train of weak shocks traveling at different velocities. Additionally, the normal shock was seen to diffuse the momentum in the transverse direction, affecting the shock rise and the rounding-off observed at the continuum scale measurements. The numerical simulations indicate that the reflections at the interfaces, wave scattering, and interference of these reflected waves are the primary mechanisms for the observed rough shock fronts.
    Mot-clé:
    Shock structure, Shock compression, Composite, Plate impact, Digital image correlation, and Meso-scale
    Assujettir:
    Engineering and Applied Science
    Créateur:
    Lawlor, Barry , Ravindran, Suraj , Gandhi, Vatsa , and Ravichandran, Guruswami
    Donateur:
    Jio Institute
    Owner:
    n.sakthivel@jioinstitute.edu.in
    Éditeur:
    Elsevier
    Emplacement:
    United States
    La langue:
    English
    Date de téléchargement:
    21-03-2023
    Date modifiée:
    21-03-2023
    date créée:
    01-02-2023
    Rights Statement Tesim:
    In Copyright
    License Tesim:
    All rights reserved
    Resource Type:
    Article
    Identificateur:
    10.1016/j.jmps.2023.105239