| dc.contributor.advisor |
Kovar , Desiderio |
|
| dc.contributor.committeeMember |
Taleff , Eric M . |
|
| dc.contributor.committeeMember |
Rodin , Gregory J . |
|
| dc.contributor.committeeMember |
Bourell , David L . |
|
| dc.contributor.committeeMember |
Haberman , Michael R . |
|
| dc.creator |
Mikulak , James Kevin |
|
| dc.date.accessioned |
2012 -02 -06T21 :31 :48Z |
|
| dc.date.available |
2012 -02 -06T21 :31 :48Z |
|
| dc.date.created |
2011 -12 |
|
| dc.date.issued |
2012 -02 -06 |
|
| dc.date.submitted |
December 2011 |
|
| dc.identifier.uri |
http : / /hdl .handle .net /2152 /ETD -UT -2011 -12 -4565 |
|
| dc.description.abstract |
Size effects in out -of -plane bending stiffness of honeycomb cellular materials were studied using analytical mechanics of solids modeling , fabrication of samples and mechanical testing . Analysis predicts a positive size -effect relative to continuum model predictions in the flexure stiffness of a honeycombed beam loaded in out -of -plane bending . A method of determining the magnitude of that effect for several different methods of constructing or assembling square -celled and hexagonal -celled materials , using both single -walled and doubled -walled construction methods is presented . Hexagonal and square -celled honeycombs , with varying volume fractions were fabricated in Nylon 12 using Selective Laser Sintering . The samples were mechanically tested in three -point and four point -bending to measure flexure stiffness . The results from standard three -point flexure tests , did not agree with predictions based on a mechanics of solids model for either square or hexagonal -celled samples . Results for four -point bending agreed with the mechanics of solids model for the square -celled geometries but not for the hexagonal -celled geometries . A closed form solution of an elasticity model for the response of the four -point bending configuration was developed , which allows interpretation of recorded displacement data at two points and allows separation the elastic bending from the localized , elastic /plastic deformation that occurs between the loading rollers and the specimen’s surface . This localized deformation was significant in the materials tested . With this analysis , the four -point bending data agreed well with the mechanics of solids predictions . |
|
| dc.format.mimetype |
application /pdf |
|
| dc.language.iso |
eng |
|
| dc.subject |
Size effects |
|
| dc.subject |
Out -of -plane bending |
|
| dc.subject |
Elastic bending |
|
| dc.subject |
Additive manufacturing |
|
| dc.subject |
Selective laser sintering |
|
| dc.subject |
Honeycombs |
|
| dc.subject |
Mechanics of solids |
|
| dc.subject |
Nylon 12 |
|
| dc.subject |
PA12 |
|
| dc.subject |
Bending stiffness |
|
| dc.subject |
Mechanical testing |
|
| dc.subject |
Cellular solids |
|
| dc.subject |
Cellular foams |
|
| dc.subject |
Foams |
|
| dc.subject |
Square -celled honeycombs |
|
| dc.subject |
Hexagonal -celled honeycombs |
|
| dc.subject |
Elasticity |
|
| dc.title |
Size effects in out -of -plane bending in elastic honeycombs fabricated using additive manufacturing : modeling and experimental results |
|
| dc.description.department |
Materials Science and Engineering |
|
| dc.type.genre |
thesis |
* |
| dc.type.material |
text |
* |
| thesis.degree.name |
Doctor of Philosophy |
|
| thesis.degree.level |
Doctoral |
|
| thesis.degree.discipline |
Materials Science and Engineering |
|
| thesis.degree.grantor |
University of Texas at Austin |
|
| thesis.degree.department |
Materials Science and Engineering |
|
| dc.date.updated |
2012 -02 -06T21 :32 :06Z |
|
| dc.identifier.slug |
2152 /ETD -UT -2011 -12 -4565 |
|