| dc.contributor |
Dr. Denis R. Cormier , Committee Chair |
|
| dc.contributor |
Dr. Ola L. A. Harrysson, Committee Member |
|
| dc.contributor |
Mr. Bryan Laffitte, Committee Member |
|
| dc.creator |
Kumar, Vikas |
|
| dc.date |
2010-04-02T18:09:35Z |
|
| dc.date |
2010-04-02T18:09:35Z |
|
| dc.date |
2009-11-05 |
|
| dc.date.accessioned |
2023-02-24T18:25:18Z |
|
| dc.date.available |
2023-02-24T18:25:18Z |
|
| dc.identifier |
etd-05082009-111342 |
|
| dc.identifier |
http://www.lib.ncsu.edu/resolver/1840.16/2011 |
|
| dc.identifier.uri |
http://localhost:8080/xmlui/handle/CUHPOERS/260218 |
|
| dc.description |
Non-stochastic lattice structures are 3-dimensional arrays of unit cells having carefully engineered geometric properties. Until recently, these structures were not practical to manufacture. The emergence of Solid Freeform Fabrication (SFF) processes in recent years has changed that fact. It is now possible to tailor structural, thermal, or electrical properties by varying the shape and density the unit cell geometry.
In this research, electrical conductivity of five different lattice cell geometries has been calculated. The geometries examined include regular hexahedrons, octahedrons, truncated octahedrons, rhombic dodecahedrons, and hexagonal lattices. The relationship between ligament length, ligament radius, relative density and electrical conductivity has been analytically derived and compared for the different cell geometries. The analysis indicates that electrical conductivity is dependent on the shape of the cell; it increases with increase in density and is linearly dependent on density at low density. Resistivity measurement of Ti-6Al-4V rhombic dodecahedrons and hexagonal lattices made via the Electron Beam Melting (EBM) process over a range of relative densities from 4% to 16% validates the effective unit cell approach for predicting electrical conductivity and the dependence of electrical conductivity on foam density.
In the second part a novel concept of varying density of metal foam to obtain specific advantage in properties has been discussed. The problem of uneven distribution of resistance faced by a specific application utilizing electrical resistivity of metal foam has been analyzed, and an approach based on varying foam density is suggested. |
|
| dc.rights |
I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dis
sertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee.
I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I
retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. |
|
| dc.subject |
varying density lattice structures |
|
| dc.subject |
Electrical conductivity |
|
| dc.subject |
metal foams |
|
| dc.subject |
non-stochastic lattice structures |
|
| dc.subject |
effective unit cell approach |
|
| dc.title |
Effect of Shape and Density on Electrical Conductivity of Non-Stochastic Lattice Structures |
|