Highly porous microlattices as ultrathin and efficient impact absorbers
The deformation and impact energy absorption properties of ultrathin polymeric microlattices were investigated as a function of density, size and positional eccentricity of the trusses, which controlled the amount of bending in the microlattice deformations. We considered highly porous, 3-D microstr...
Saved in:
Main Authors: | , |
---|---|
Other Authors: | |
Format: | Article |
Language: | English |
Published: |
2018
|
Subjects: | |
Online Access: | https://hdl.handle.net/10356/89486 http://hdl.handle.net/10220/47069 |
Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
Institution: | Nanyang Technological University |
Language: | English |
id |
sg-ntu-dr.10356-89486 |
---|---|
record_format |
dspace |
spelling |
sg-ntu-dr.10356-894862020-09-26T22:17:17Z Highly porous microlattices as ultrathin and efficient impact absorbers Lai, Chang Quan Daraio, Chiara Temasek Laboratories Negative Poisson's Ratio DRNTU::Engineering::General Auxetic The deformation and impact energy absorption properties of ultrathin polymeric microlattices were investigated as a function of density, size and positional eccentricity of the trusses, which controlled the amount of bending in the microlattice deformations. We considered highly porous, 3-D microstructures with small lattice constants (≤135 μm), and studied their response to high strain rate (∼1000/s) tests, using high speed video capture, SEM imaging and quantitative modelling. The microlattices were found to have excellent impact absorption efficiencies that are 2 - 120 times better than carbon nanotube foams, polycarbonate and silicone rubber, despite being an order of magnitude slimmer than the thinnest commercial foams of similar densities. This high impact absorption efficiency is largely due to the sideways buckling of the microlattice trusses during the crushing stage, which prevented densification of the microlattices at small strains. Furthermore, we showed that varying the positional eccentricity of the trusses and the number of unit cells in the microlattices can modulate their stiffness, strength and energy absorption over an appreciable range, comparable to that obtained through modifications in relative density. Because the microlattices were mostly under stress equilibrium during the impact process, the insights derived from the present study are expected to be valid for quasistatic and low strain rate loadings as well. Accepted version 2018-12-18T08:49:11Z 2019-12-06T17:26:46Z 2018-12-18T08:49:11Z 2019-12-06T17:26:46Z 2018 2018 Journal Article Lai, C. Q., & Daraio, C. (2018). Highly porous microlattices as ultrathin and efficient impact absorbers. International Journal of Impact Engineering, 120, 138-149. doi:10.1016/j.ijimpeng.2018.05.014 0734-743X https://hdl.handle.net/10356/89486 http://hdl.handle.net/10220/47069 10.1016/j.ijimpeng.2018.05.014 208257 en International Journal of Impact Engineering © 2018 Elsevier. This is the author created version of a work that has been peer reviewed and accepted for publication by International Journal of Impact Engineering, Elsevier. It incorporates referee’s comments but changes resulting from the publishing process, such as copyediting, structural formatting, may not be reflected in this document. The published version is available at: [http://dx.doi.org/10.1016/j.ijimpeng.2018.05.014]. 50 p. application/pdf |
institution |
Nanyang Technological University |
building |
NTU Library |
country |
Singapore |
collection |
DR-NTU |
language |
English |
topic |
Negative Poisson's Ratio DRNTU::Engineering::General Auxetic |
spellingShingle |
Negative Poisson's Ratio DRNTU::Engineering::General Auxetic Lai, Chang Quan Daraio, Chiara Highly porous microlattices as ultrathin and efficient impact absorbers |
description |
The deformation and impact energy absorption properties of ultrathin polymeric microlattices were investigated as a function of density, size and positional eccentricity of the trusses, which controlled the amount of bending in the microlattice deformations. We considered highly porous, 3-D microstructures with small lattice constants (≤135 μm), and studied their response to high strain rate (∼1000/s) tests, using high speed video capture, SEM imaging and quantitative modelling. The microlattices were found to have excellent impact absorption efficiencies that are 2 - 120 times better than carbon nanotube foams, polycarbonate and silicone rubber, despite being an order of magnitude slimmer than the thinnest commercial foams of similar densities. This high impact absorption efficiency is largely due to the sideways buckling of the microlattice trusses during the crushing stage, which prevented densification of the microlattices at small strains. Furthermore, we showed that varying the positional eccentricity of the trusses and the number of unit cells in the microlattices can modulate their stiffness, strength and energy absorption over an appreciable range, comparable to that obtained through modifications in relative density. Because the microlattices were mostly under stress equilibrium during the impact process, the insights derived from the present study are expected to be valid for quasistatic and low strain rate loadings as well. |
author2 |
Temasek Laboratories |
author_facet |
Temasek Laboratories Lai, Chang Quan Daraio, Chiara |
format |
Article |
author |
Lai, Chang Quan Daraio, Chiara |
author_sort |
Lai, Chang Quan |
title |
Highly porous microlattices as ultrathin and efficient impact absorbers |
title_short |
Highly porous microlattices as ultrathin and efficient impact absorbers |
title_full |
Highly porous microlattices as ultrathin and efficient impact absorbers |
title_fullStr |
Highly porous microlattices as ultrathin and efficient impact absorbers |
title_full_unstemmed |
Highly porous microlattices as ultrathin and efficient impact absorbers |
title_sort |
highly porous microlattices as ultrathin and efficient impact absorbers |
publishDate |
2018 |
url |
https://hdl.handle.net/10356/89486 http://hdl.handle.net/10220/47069 |
_version_ |
1681057059654598656 |