Investigation of Traditional and Alternate Living Hinge Designs for Fused Deposition Modeling

119 Pages·2017·3.83 MB·English

by  Cassandra Sue Gribbins

Dissertations and Theses
8-2014
Investigation of Traditional and Alternate Living Hinge Designs for
Fused Deposition Modeling Additive Manufacturing Process
Cassandra Sue Gribbins
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Gribbins, Cassandra Sue, "Investigation of Traditional and Alternate Living Hinge Designs for Fused
Deposition Modeling Additive Manufacturing Process" (2014). Dissertations and Theses. 213.
https://commons.erau.edu/edt/213
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INVESTIGATION OF TRADITIONAL AND ALTERNATE LIVING HINGE
DESIGNS FOR FUSED DEPOSITION MODELING ADDITIVE MANUFACTURING
PROCESS

by

Cassandra Sue Gribbins

A Thesis Submitted to the College of Engineering Department of Mechanical
Engineering in Partial Fulfillment of the Requirements for the Degree of
Master of Science in Mechanical Engineering

Embry-Riddle Aeronautical University
Daytona Beach, Florida
August 2014
i
Acknowledgements
My sincere gratitude goes to Dr. Heidi M. Steinhauer and Mr. Raul Rumbaut for
the support and guidance as well as keeping me focused with the much needed reminder
to just “Finish it!” I would not be where I am at today without your mentorship and care.
I am also very grateful for all of the help and direction from Dr. Sypeck and Mr. Potash
with the material testing. Thank you as well to Dr. Rollin and Dr. Dhainaut for the
feedback and guidance.
I would also like to thank my “pamily” for providing laughter and pep talks
throughout the process. To my wonderful boyfriend, thank you for making me realize
that courage is the magic that turns dreams into reality.

iii
Abstract
Researcher: Cassandra Sue Gribbins
Title: Investigation of Traditional and Alternate Living Hinge Designs for Fused
Deposition Modeling Additive Manufacturing Process
Institution: Embry-Riddle Aeronautical University
Degree: Master of Science in Mechanical Engineering
Year: 2014
A manuscript-style thesis composed of three studies covered the application of living
hinge designs in the additive manufacturing process of fused deposition modeling. Initial
research included comparing numerical and analytical linear analyses on a traditional
living hinge design. The second research consisted of tensile testing for the material
properties of the Acrylonitrile Butadiene Styrene (ABS) used in fused deposition
modeling (FDM) process by the MakerBot 2X as well as adjusting the traditional design
to be printed. The third study explored alternate living hinge designs that utilize the
geometric freedom provided by additive manufacturing to more evenly distribute stress
across the hinge. The traditional living hinge design is not feasible for FDM ABS while
alternate designs such as a longer hinge length or wave pattern demonstrated minimal
stress experienced across the hinge. Further research on optimizing alternate designs is
encouraged.

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Table of Contents
Thesis Review Committee .................................................................................................. ii
Acknowledgements ............................................................................................................ iii
Abstract .............................................................................................................................. iv
List of Tables ................................................................................................................... viii
List of Figures .................................................................................................................... ix
Chapter 1
Thesis Introduction ............................................................................................... 1
Significance of the Study .............................................................................................. 2
Statement of the Problem .............................................................................................. 2
Purpose Statement ......................................................................................................... 3
Delimitations ................................................................................................................. 3
Limitations and Assumptions ....................................................................................... 3
Organization of the Thesis ............................................................................................ 4
Chapter 2: Comparison of Numerical and Analytical Solutions of an ABS
Additively Manufactured Living Hinge ..................................................... 4
Chapter 3: Experimental Analysis on an Additively Manufactured ABS
Living Hinge ............................................................................................... 7
Chapter 4: Exploration of Alternate Living Hinge Designs for Entry Level
FDM Systems.............................................................................................. 9
Chapter Five: Thesis Conclusion .................................................................... 10
Definitions of Terms ................................................................................................... 11
List of Acronyms ........................................................................................................ 12
References ................................................................................................................... 13

v
Chapter 2
Comparison of Numerical and Analytical Solutions of an ABS
Additively Manufactured Living Hinge ....................................................... 15
Abstract ....................................................................................................................... 16
Introduction ................................................................................................................. 17
Technical Objective and Approach ............................................................................. 22
Related Theory ............................................................................................................ 24
Experiments ................................................................................................................ 31
Results and Discussion ............................................................................................... 36
Conclusions and Future Work .................................................................................... 40
References ................................................................................................................... 42
Chapter 3
Experimental Analysis on an Additively Manufactured ABS Living
Hinge......................................................................................................................... 44
Abstract ....................................................................................................................... 45
Introduction ................................................................................................................. 46
Experiments ................................................................................................................ 48
Material Testing .............................................................................................. 48
Application Testing ......................................................................................... 53
Results and Discussion ............................................................................................... 57
Material Testing Results ................................................................................. 57
Application Testing Results ............................................................................ 61
Conclusion and Future Work ...................................................................................... 64
References ................................................................................................................... 66
Chapter 4
Exploration of Alternate Living Hinge Designs for Entry Level FDM
Systems .................................................................................................... 68
Abstract ....................................................................................................................... 69
vi
Introduction ................................................................................................................. 70
Experimental Setup ..................................................................................................... 74
Results and Discussion ............................................................................................... 79
Conclusions and Future Work .................................................................................... 89
References ................................................................................................................... 90
Chapter 5
Thesis Conclusion ................................................................................... 92
Summary and Conclusions ......................................................................................... 92
Summary ......................................................................................................... 92
Future Work .................................................................................................... 93
Conduct Experimental Application Testing ............................................ 93
Refine Finite Element Analysis ................................................................ 94
Optimize Alternate Designs ...................................................................... 94
Conclusion ...................................................................................................... 95
Appendices ....................................................................................................................... 96
Appendix A ........................................................................................................... 96
Appendix B ........................................................................................................... 97
Appendix C ........................................................................................................... 98
Appendix D ........................................................................................................... 99
Appendix E ......................................................................................................... 103
Appendix F.......................................................................................................... 104
Appendix G ......................................................................................................... 105

vii
List of Tables
Page
Chapter 2 .....................................................................................................15
Table 2.1 Analytical approach user input variables – traditional PP design geometry ..... 34
Table 2.2 Analytical approach user input variables - adjusted AM design geometry ....... 36
Table 2.3 Results for Numerical and Analytical Approach for Traditional PP and Adjusted
AM Design Geometry at Enforced Displacements of 0.7 mm and 4.0 mm ......... 38
Chapter 3 .....................................................................................................44
Table 3.1 Tensile testing measurements for determination of usable cross-sectional area
............................................................................................................................... 58
Table 3.2 Summary of material properties obtained from tensile testing ......................... 61
Table 3.3 Measurements for a set of traditional designed living hinges ........................... 63
Chapter 4 .....................................................................................................68
Table 4.1 CATIA V5 R20 FEA von Mises results summary including the result for the
traditional 3 mm hinge from Gribbins and Steinhauer (2014) for comparison .... 88

viii
List of Figures
Page
Chapter 1 ....................................................................................................... 1
Figure 1.1 A common living hinge design illustrating major geometric design features
and the result of bending 180° (Tres, 2000) ........................................................... 4
Figure 1.2 Plastic pencil case hinges: A. Rigid-body mechanical hinges and B. Living
hinge ........................................................................................................................ 5
Figure 1.3 Automobile electrical junction box cover containing four living hinges (Kim et
al., 2003). ................................................................................................................ 5
Figure 1.4 Electronic sheet with living hinge design: A. Overview of entire sheet
containing 32 tiles connected by living hinges and B. Close-up of a single fold
from a silicone flexure (Hawkes et al., 2010) ......................................................... 6
Figure 1.5 Living hinge on a Tic Tac mint case (Objet Geometries Ltd., 2010) ................ 6
Figure 1.6 General dimensions for a polypropylene living hinge adapted from (Hoffman,
2004) ....................................................................................................................... 7
Figure 1.7 Diagram of the Fused Deposition Modeling Process (Ahn et al., 2002) ........... 9
Chapter 2 .....................................................................................................15
Figure 2.1 Defining design geometry for a living hinge in the a) opened position and b)
closed position (Tres, 2000) .................................................................................. 18
Figure 2.2 Automobile electrical junction box cover highlighting two sets of living hinges
(Kim et al., 2003). ................................................................................................. 18
Figure 2.3 Living hinge on a Tic Tac® mint case (Objet Geometries Ltd., 2010) ........... 19
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