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Ravichandran, Guruswami
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- Descripción:
- Shock compression plate impact experiments conventionally rely on point-wise velocimetry measurements based on laser-based interferometric techniques. This study presents an experimental methodology to measure the free surface full-field particle velocity in shock compression experiments using high-speed imaging and three-dimensional (3D) digital image correlation (DIC). The experimental setup has a temporal resolution of 100 ns with a spatial resolution varying from 90 to 200 μm/pixel. Experiments were conducted under three different plate impact configurations to measure spatially resolved free surface velocity and validate the experimental technique. First, a normal impact experiment was conducted on polycarbonate to measure the macroscopic full-field normal free surface velocity. Second, an isentropic compression experiment on Y-cut quartz–tungsten carbide assembly is performed to measure the particle velocity for experiments involving ramp compression waves. To explore the capability of the technique in multiaxial loading conditions, a pressure shear plate impact experiment was conducted to measure both the normal and transverse free surface velocities under combined normal and shear loading. The velocities measured in the experiments using digital image correlation are validated against previous data obtained from laser interferometry. Numerical simulations were also performed using established material models to compare and validate the experimental velocity profiles for these different impact configurations. The novel ability of the employed experimental setup to measure full-field free surface velocities with high spatial resolutions in shock compression experiments is demonstrated for the first time in this work.
- Palabra clave:
- Stereo Digital image correlation, Shock Compression, Full-field measurements, and High Speed imaging
- Tema:
- Applied Science and Engineering
- Creador:
- Ravindran, Suraj , Gandhi, Vatsa , Ravichandran, Guruswami , and Joshi, Akshay
- Owner:
- n.sakthivel@jioinstitute.edu.in
- Editor:
- American Institute of Physics
- Ubicación:
- United States
- Idioma:
- English
- Fecha de Subida:
- 21-03-2023
- Fecha Modificada:
- 21-03-2023
- Fecha de Creacion:
- 01-02-2023
- Rights Statement Tesim:
- In Copyright
- License Tesim:
- All rights reserved
- Resource Type:
- Article
- Identificador:
- 10.1007/s40870-022-00359-2
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- Descripción:
- 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.
- Palabra clave:
- Failure, Digital image correlation, Transient dynamic, Shock, Lattice structure, and Compaction
- Tema:
- Applied Science and Engineering
- Creador:
- Weeks, J. S. and Ravichandran, Guruswami
- Owner:
- n.sakthivel@jioinstitute.edu.in
- Editor:
- Springer Nature
- Ubicación:
- Switzerland
- Idioma:
- English
- Fecha de Subida:
- 21-03-2023
- Fecha Modificada:
- 21-03-2023
- Fecha de Creacion:
- 01-12-2022
- Rights Statement Tesim:
- In Copyright
- License Tesim:
- All rights reserved
- Resource Type:
- Article
- Identificador:
- 10.1007/s40870-022-00359-2
-
- Descripción:
- 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.
- Palabra clave:
- Shock structure, Shock compression, Composite, Plate impact, Digital image correlation, and Meso-scale
- Tema:
- Engineering and Applied Science
- Creador:
- Lawlor, Barry , Ravindran, Suraj , Gandhi, Vatsa , and Ravichandran, Guruswami
- Contribuidor:
- Jio Institute
- Owner:
- n.sakthivel@jioinstitute.edu.in
- Editor:
- Elsevier
- Ubicación:
- United States
- Idioma:
- English
- Fecha de Subida:
- 21-03-2023
- Fecha Modificada:
- 21-03-2023
- Fecha de Creacion:
- 01-02-2023
- Rights Statement Tesim:
- In Copyright
- License Tesim:
- All rights reserved
- Resource Type:
- Article
- Identificador:
- 10.1016/j.jmps.2023.105239