High strain-rate compression behavior of polymeric rod and plate Kelvin lattice structures
- Creators
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Weeks, John S.
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Ravichandran, Guruswami
Abstract
The compressive high strain-rate behavior of polymeric Kelvin lattice structures with rod-based or plate-based unit cells was investigated through experimental techniques and finite element simulations. Polymeric lattice structures with 5x5x5 unit cell geometries were manufactured on the millimeter scale using vat polymerization additive manufacturing and tested at low (0.001/s) and high (1000/s) strain-rates. High strain-rate experiments were performed and validated for a viscoelastic split-Hopkinson (Kolsky) pressure bar system (SHPB) coupled with high-speed imaging and digital image correlation (DIC). Experimental results at both low and high strain-rates show the formation of a localized deformation band which was more prevalent in low relative density specimens and low strain-rate experiments. Strain-rate effects of lattice specimens strongly correlate with effects of the base polymer material; both bulk polymer and lattice specimen demonstrated strain-rate hardening, strain-rate stiffening, and decreased fracture strain under dynamic loading. Results show mechanical failure properties and energy absorption depended strongly on the relative density of the lattice specimen and exhibited distinct scaling between relative density and geometry type (rod, plate) and loading rate. High relative density plate-lattices demonstrated inferior mechanical properties to rod-lattices; however, there exists a critical relative density for a given mechanical property (17%–28%) below which plate-lattices outperform rod-lattices of similar mass. High strain-rate explicit finite element simulations were performed and showed good agreement with the mechanical failure trends and deformation modes observed in the experiments.
Additional Information
© 2022 Elsevier. Received 16 August 2021, Revised 25 October 2021, Accepted 5 January 2022, Available online 19 January 2022. The authors gratefully acknowledge the support of DOE/NNSA, USA Award No. DE-NA0003957. The authors thank Prof. K.T. Faber (Caltech) for access to the Autodesk Ember 3D printer. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.Attached Files
Supplemental Material - 1-s2.0-S0167663622000059-mmc1.docx
Supplemental Material - 1-s2.0-S0167663622000059-mmc2.mp4
Supplemental Material - 1-s2.0-S0167663622000059-mmc3.mp4
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Additional details
- Eprint ID
- 113065
- Resolver ID
- CaltechAUTHORS:20220121-968287000
- Department of Energy (DOE) National Nuclear Security Administration
- DE-NA0003957
- Created
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2022-01-24Created from EPrint's datestamp field
- Updated
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2022-01-24Created from EPrint's last_modified field
- Caltech groups
- GALCIT