Studying the Physical Properties and Auxetic Behavior of 3D-printed Fasteners

Larry D. Peel; Mohamed Abdelrahman

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Conference: 2012 ASEE Annual Conference & Exposition
Location: San Antonio, Texas
Publication Date: June 10, 2012
Start Date: June 10, 2012
End Date: June 13, 2012
ISSN: 2153-5965
Conference Session: NSF Grantees' Poster Session
Tagged Topic: NSF Grantees Poster Session
Page Count: 12
Page Numbers: 25.1204.1 - 25.1204.12
DOI: 10.18260/1-2--21961
Permanent URL: https://peer.asee.org/21961
Download Count: 535

Paper Authors

biography

Larry D. Peel P.E. Texas A&M University, Kingsville

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Larry Peel received an A.S. from Snow College, in engineering, a B.S. in mechanical engineering from Utah State University, an M.S. in engineering mechanics from Virginia Tech, and a Ph.D. in mechanical engineering from Brigham Young University. He has taught in the area of solid mechanics, materials science, design, and manufacturing at Texas A&M University, Kingsville for the past 11 years. His research is in the area of traditional and flexible composites, morphing structures, auxetic systems, and additive manufacturing.

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Mohamed Abdelrahman Texas A&M University, Kingsville

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Abstract

Studying the Physical Properties and Auxetic Behavior of 3D-printed FastenersAbstract This paper reports the importance of fasteners and their related characteristics for specificpurposes. Fasteners are used in every industry, and in virtually every component. The idealfastener would be relatively easy to insert, but take much more force to remove. Such fastenerswould not require nuts screwed onto bolts, or other retaining rings. The current work attempts todevelop a simple fastener with a low Insertion Force / Removal Force ratio by exploiting auxeticbehavior. Auxetic materials or negative Poisson’s Ratio materials have properties that arecounter-intuitive. A rubber band, for example, becomes thinner in width when pulled atlengthwise Auxetic materials, however, will expand in width, when pulled along their length, orwhen compressed along their length, will also contract in width. Hence, normal materials havepositive Poisson’s Ratios while auxetic materials are revealed to have negative Poisson’s Ratio.By exploiting the theory behind negative Poisson’s Ratios, a suitably designed fastener canexhibit auxetic behavior. Specifically, a properly designed fastener will decrease in diameterwhen compressed through a hole and increase in diameter when pulled away from the hole.Using previously developed theory, several cylindrical fasteners were fabricated with nominaldiameters of 0.7 inches, 2 inches long, and double helix angles of (30°/45°) and (30°/60°).Aluminum sleeves were fabricated with holes of slightly different diameters, such that when thefasteners were inserted they must contract 1% to 2%. Insertion/Removal force ratios as low as18% were observed. The project is considered a success and could lead to patents and be a boonto the fastener industry. A learning module based on the legacy cycle concept is developed that challenges thestudents to think through the processes and steps required to design fasteners for specificindustry uses. A 3-D printer will allow experimentation with the best class design. This learningmodule will be introduced into a high school mathematics class during the 2011-2012 schoolyear. Assessment of the students’ performance will be carried out and reported.

Citation
Format

Peel, L. D., & Abdelrahman, M. (2012, June), Studying the Physical Properties and Auxetic Behavior of 3D-printed Fasteners Paper presented at 2012 ASEE Annual Conference & Exposition, San Antonio, Texas. 10.18260/1-2--21961

TY - CPAPER
AB - Studying the Physical Properties and Auxetic Behavior of 3D-printed FastenersAbstract This paper reports the importance of fasteners and their related characteristics for specificpurposes. Fasteners are used in every industry, and in virtually every component. The idealfastener would be relatively easy to insert, but take much more force to remove. Such fastenerswould not require nuts screwed onto bolts, or other retaining rings. The current work attempts todevelop a simple fastener with a low Insertion Force / Removal Force ratio by exploiting auxeticbehavior. Auxetic materials or negative Poisson’s Ratio materials have properties that arecounter-intuitive. A rubber band, for example, becomes thinner in width when pulled atlengthwise Auxetic materials, however, will expand in width, when pulled along their length, orwhen compressed along their length, will also contract in width. Hence, normal materials havepositive Poisson’s Ratios while auxetic materials are revealed to have negative Poisson’s Ratio.By exploiting the theory behind negative Poisson’s Ratios, a suitably designed fastener canexhibit auxetic behavior. Specifically, a properly designed fastener will decrease in diameterwhen compressed through a hole and increase in diameter when pulled away from the hole.Using previously developed theory, several cylindrical fasteners were fabricated with nominaldiameters of 0.7 inches, 2 inches long, and double helix angles of (30°/45°) and (30°/60°).Aluminum sleeves were fabricated with holes of slightly different diameters, such that when thefasteners were inserted they must contract 1% to 2%. Insertion/Removal force ratios as low as18% were observed. The project is considered a success and could lead to patents and be a boonto the fastener industry. A learning module based on the legacy cycle concept is developed that challenges thestudents to think through the processes and steps required to design fasteners for specificindustry uses. A 3-D printer will allow experimentation with the best class design. This learningmodule will be introduced into a high school mathematics class during the 2011-2012 schoolyear. Assessment of the students’ performance will be carried out and reported.
AU - Larry D. Peel P.E.
AU - Mohamed Abdelrahman
CY - San Antonio, Texas
DA - 2012/06/10
PB - ASEE Conferences
TI - Studying the Physical Properties and Auxetic Behavior of 3D-printed Fasteners
UR - https://peer.asee.org/21961
DO - 10.18260/1-2--21961
ER -