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['Laboratory for Freeform Fabrication', 'University of Texas at Austin'] | 2018-04-10T15:54:05Z | 2018-04-10T15:54:05Z | 1990 | Mechanical Engineering | doi:10.15781/T20R9MM7Z | http://hdl.handle.net/2152/64232 | eng | 1990 International Solid Freeform Fabrication Symposium | Open | ['Laboratory for Freeform Fabrication', 'Annual International Solid Freeform Fabrication Symposium', 'Table of Contents'] | 1990 Annual International Solid Freeform Fabrication Symposium Table of Contents | Conference proceedings | https://repositories.lib.utexas.edu//bitstreams/05e27a82-99b2-45d1-a692-a248aeb63942/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T14:39:06Z | 2022-08-23T14:39:06Z | 1990 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115349', 'http://dx.doi.org/10.26153/tsw/42249'] | eng | 1990 International Solid Freeform Fabrication Symposium | Open | table of contents | 1990 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/e75c0431-5a10-4b46-ad84-46a7bfe3f0a2/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T16:54:52Z | 2022-08-23T16:54:52Z | 1991 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115353', 'http://dx.doi.org/10.26153/tsw/42253'] | eng | 1991 International Solid Freeform Fabrication Symposium | Open | table of contents | 1991 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/f3bfeae7-ecdd-4214-9c63-e3dd5cfd2bb2/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T16:56:10Z | 2022-08-23T16:56:10Z | 1992 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115354', 'http://dx.doi.org/10.26153/tsw/42254'] | eng | 1992 International Solid Freeform Fabrication Symposium | Open | table of contents | 1992 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/ca3cc84d-3932-46b6-9bf0-10a43a0215a3/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T16:57:15Z | 2022-08-23T16:57:15Z | 1993 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115355', 'http://dx.doi.org/10.26153/tsw/42255'] | eng | 1993 International Solid Freeform Fabrication Symposium | Open | table of contents | 1993 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/72119455-4ccd-4827-a74d-fba68589ed3a/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T16:58:01Z | 2022-08-23T16:58:01Z | 1994 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115356', 'http://dx.doi.org/10.26153/tsw/42256'] | eng | 1994 International Solid Freeform Fabrication Symposium | Open | table of contents | 1994 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/cf9b9c26-2ab9-4c7a-a3f0-bfe34bb1ad12/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T16:59:05Z | 2022-08-23T16:59:05Z | 1995 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115357', 'http://dx.doi.org/10.26153/tsw/42257'] | eng | 1995 International Solid Freeform Fabrication Symposium | Open | table of contents | 1995 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/4329961e-8534-4687-9f52-8f041bb18f6d/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T16:59:58Z | 2022-08-23T16:59:58Z | 1996 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115358', 'http://dx.doi.org/10.26153/tsw/42258'] | eng | 1996 International Solid Freeform Fabrication Symposium | Open | table of contents | 1996 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/40fc45a9-1b4b-404a-9eff-dd1c6cdcc269/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:00:53Z | 2022-08-23T17:00:53Z | 1997 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115359', 'http://dx.doi.org/10.26153/tsw/42259'] | eng | 1997 International Solid Freeform Fabrication Symposium | Open | table of contents | 1997 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/4eea6bbb-3d12-49bc-a9af-9227042aec85/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:01:47Z | 2022-08-23T17:01:47Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115360', 'http://dx.doi.org/10.26153/tsw/42260'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | table of contents | 1998 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/6f2913d8-b81a-4a73-a3b2-619f617e5f22/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:02:48Z | 2022-08-23T17:02:48Z | 1999 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115361', 'http://dx.doi.org/10.26153/tsw/42261'] | eng | 1999 International Solid Freeform Fabrication Symposium | Open | ['table of contents', 't'] | 1999 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/d353e0d0-0aaa-4b00-bc18-7bc86eed3032/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:06:19Z | 2022-08-23T17:06:19Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115362', 'http://dx.doi.org/10.26153/tsw/42262'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | table of contents | 2000 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/6a3c1a7f-83ca-46af-a660-3528baa2ca87/download | null | null | null | null | null | null | null | null |
International Solid Freeform Fabrication Symposium | 2019-06-13T13:56:34Z | 2019-06-13T13:56:34Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/74939', 'http://dx.doi.org/10.26153/tsw/2051'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Eleventh Solid Freeform Fabrication (SFF) Symposium | 2000 Preface | Conference paper | https://repositories.lib.utexas.edu//bitstreams/15e04d72-920f-4dd6-aaae-cdbd9c866e7b/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:07:35Z | 2022-08-23T17:07:35Z | 2001 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115363', 'http://dx.doi.org/10.26153/tsw/42263'] | eng | 2001 International Solid Freeform Fabrication Symposium | Open | table of contents | 2001 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/6f8c99c1-c606-4d3e-9556-e21d2db217d2/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:09:06Z | 2022-08-23T17:09:06Z | 2002 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115364', 'http://dx.doi.org/10.26153/tsw/42264'] | eng | 2002 International Solid Freeform Fabrication Symposium | Open | table of contents | 2002 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/e20ae9f5-d2da-43da-9ea6-ae6c6e966a60/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:10:34Z | 2022-08-23T17:10:34Z | 2003 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115365', 'http://dx.doi.org/10.26153/tsw/42265'] | eng | 2003 International Solid Freeform Fabrication Symposium | Open | table of contents | 2003 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/69407420-e70d-409b-82e3-45cf08f61289/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:11:56Z | 2022-08-23T17:11:56Z | 2004 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115366', 'http://dx.doi.org/10.26153/tsw/42266'] | eng | 2004 International Solid Freeform Fabrication Symposium | Open | table of contents | 2004 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/51061f27-b489-4f7d-a4e1-85ef7ee1b631/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:14:22Z | 2022-08-23T17:14:22Z | 2005 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115367', 'http://dx.doi.org/10.26153/tsw/42267'] | eng | 2005 International Solid Freeform Fabrication Symposium | Open | table of contents | 2005 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/4011ba2d-357c-4894-991b-9d8c77e44816/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:15:55Z | 2022-08-23T17:15:55Z | 2006 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115368', 'http://dx.doi.org/10.26153/tsw/42268'] | eng | 2006 International Solid Freeform Fabrication Symposium | Open | table of contents | 2006 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/f29f2722-e6c5-40b4-ac6b-3b57009ef0b7/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:17:26Z | 2022-08-23T17:17:26Z | 2007 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115369', 'http://dx.doi.org/10.26153/tsw/42269'] | eng | 2007 International Solid Freeform Fabrication Symposium | Open | table of contents | 2007 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/65d3f831-0909-4c28-b78e-4a444eedbda2/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:18:39Z | 2022-08-23T17:18:39Z | 2008 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115370', 'http://dx.doi.org/10.26153/tsw/42270'] | eng | 2008 International Solid Freeform Fabrication Symposium | Open | table of contents | 2008 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/09c22417-6b60-46ca-b396-49d3152d247f/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:20:00Z | 2022-08-23T17:20:00Z | 2009 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115371', 'http://dx.doi.org/10.26153/tsw/42271'] | eng | 2009 International Solid Freeform Fabrication Symposium | Open | table of contents | 2009 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/1b9a7d9e-30db-4eae-930f-ed8924811bd7/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:21:01Z | 2022-08-23T17:21:01Z | 2010 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115372', 'http://dx.doi.org/10.26153/tsw/42272'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | table of contents | 2010 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/e0adb26a-8a6a-4290-879f-b1e99a47d7b6/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:22:23Z | 2022-08-23T17:22:23Z | 2011 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115373', 'http://dx.doi.org/10.26153/tsw/42273'] | eng | 2011 International Solid Freeform Fabrication Symposium | Open | table of contents | 2011 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/94bde5e9-2a8f-4162-b57b-072ff206423d/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:23:31Z | 2022-08-23T17:23:31Z | 2012 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115374', 'http://dx.doi.org/10.26153/tsw/42274'] | eng | 2012 International Solid Freeform Fabrication Symposium | Open | table of contents | 2012 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/52f50796-dd3a-4553-ad69-fd6cbfbd9ea7/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:24:52Z | 2022-08-23T17:24:52Z | 2013 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115375', 'http://dx.doi.org/10.26153/tsw/42275'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | table of contents | 2013 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/84cbabea-2091-41a4-89a8-98dee2468a78/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:26:12Z | 2022-08-23T17:26:12Z | 2014 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115376', 'http://dx.doi.org/10.26153/tsw/42276'] | eng | 2014 International Solid Freeform Fabrication Symposium | Open | table of contents | 2014 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/cf72eabd-ec1d-43e2-b8b2-bf34cb3b3e5a/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:27:28Z | 2022-08-23T17:27:28Z | 2015 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115377', 'http://dx.doi.org/10.26153/tsw/42277'] | eng | 2015 International Solid Freeform Fabrication Symposium | Open | table of contents | 2015 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/87232740-d486-4e83-8cc9-7082f1c2e09b/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:28:33Z | 2022-08-23T17:28:33Z | 2016 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115378', 'http://dx.doi.org/10.26153/tsw/42278'] | eng | 2016 International Solid Freeform Fabrication Symposium | Open | table of contents | 2016 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/5a2bf1f8-5e38-49e7-b407-57a8cd4d6ad6/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-23T17:29:45Z | 2022-08-23T17:29:45Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115379', 'http://dx.doi.org/10.26153/tsw/42279'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | table of contents | 2017 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/bc197195-896d-40da-b84e-fd90f0d10106/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-29T16:41:04Z | 2022-08-29T16:41:04Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115419', 'http://dx.doi.org/10.26153/tsw/42318'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | table of contents | 2018 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/351ab080-bc01-403f-b38b-68a2531f2f13/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-29T16:43:07Z | 2022-08-29T16:43:07Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115420', 'http://dx.doi.org/10.26153/tsw/42319'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | table of contents | 2019 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/d20e2a77-3afe-480b-bcdc-309bf272325b/download | null | null | null | null | null | null | null | null |
Laboratory for Freeform Fabrication and University of Texas at Austin | 2022-08-29T16:44:44Z | 2022-08-29T16:44:44Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/115421', 'http://dx.doi.org/10.26153/tsw/42320'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | table of contents | 2021 International Solid Freeform Fabrication Symposium Table of Contents | Other | https://repositories.lib.utexas.edu//bitstreams/e694c010-15df-40d1-ab03-ae5e1f98140e/download | null | null | null | null | null | null | null | null |
University of Texas at Austin | 2024-03-25T21:56:03Z | 2024-03-25T21:56:03Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124308', 'https://doi.org/10.26153/tsw/50916'] | null | 2023 International Solid Freeform Fabrication Symposium | Open | ['preface', 'committee', '2023 Solid Freeform Fabrication Symposium'] | 2023 International Solid Freeform Fabrication Symposium Preface and Organizing Committee | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7b8a6d7e-421c-4530-af41-a666a67e112d/download | University of Texas at Austin | null | null | null | null | null | null | null |
['Roosendaal, Mark D. Van', 'Chamberlain, Peter', 'Thomas, Charles'] | 2019-02-26T16:27:06Z | 2019-02-26T16:27:06Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73481', 'http://dx.doi.org/10.26153/tsw/631'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['Haar wavelet', 'Control variable'] | 2D Wavelet Analysis of Solid Objects: Applications in Layered Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e7834ace-db27-4ee3-9cc8-6fa4767d8c63/download | null | In this paper, we introduce two-dimensional discrete wavelet basis functions and their
application in the analysis and modeling ofsurface topography in layered manufacturing objects.
In previous work, a one dimensional wavelet transform technique was developed to generate
variable thickness layers. [1] For vertical edge layers Haar wavelet decomposition is used the
slicing direction but is not useful in the slicing plane. For frequency analysis within the slicing
plane, biorthogonal wavelets provide the desired analysis ability. When analyzing layered
manufacturing with ruled edges a true 2-D transform is appropriate. Two-dimensional wavelet
analysis simultaneously controls the layer thickness as well as the density of control points
required the surface definition of each layer edge. | null | null | null | null | null | null |
['Todd, J.A.', 'Copley, S.M.', 'Yankova, M.I.', 'Fariborzi, F.', 'West, K.'] | 2018-11-02T16:38:38Z | 2018-11-02T16:38:38Z | 1995 | Mechanical Engineering | doi:10.15781/T2HQ3SJ0S | http://hdl.handle.net/2152/69338 | eng | 1995 International Solid Freeform Fabrication Symposium | Open | ['CAD/CAM', 'polarization', 'beam power'] | 3-D Laser Shaping of Ceramic and Ceramic Composite Materials | Conference paper | https://repositories.lib.utexas.edu//bitstreams/0873ca49-b55b-4926-a47f-ae240fb6ec24/download | null | A versatile, automated, laser-based system, capable of producing complex threedimensional
shapes of ceramic and ceramic composite materials, through either controlled layer
ablation or solid freeform fabrication, is currently under development. The system comprises
a 1.2 kW C021aser, positioning system, beam scanner, non-contacting positioning sensor, beam
conditioner and CAD/CAM system. This paper reports progress in relating machine parameters
(scan rate, feed, beam power and polarization) to process measurables (material removal rate
and surface roughness), and demonstrates the potential for rapid prototyping and direct
manufacturing of: (a) rotationally symmetric components based on ablative ceramics such as
Si3N4 and (b) graphite fuel cell plenums | null | null | null | null | null | null |
['Li, Xuxiao', 'Tan, Wenda'] | 2021-11-03T20:36:23Z | 2021-11-03T20:36:23Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89926 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['grain structure', 'cellular automata', 'direct laser deposition', 'metal additive manufacturing'] | 3-Dimensional Cellular Automata Simulation of Grain Structure in Metal Additive Manufacturing Process | Conference paper | https://repositories.lib.utexas.edu//bitstreams/6bcb8670-a4ac-4b53-809c-04a1b04fbf9e/download | University of Texas at Austin | Distinct grain structures have been observed in Metal Additive Manufacturing (MAM)
processes. These grain structures feature columnar grains which occasionally mix with equiaxed
grains. The occurrence of these grain structures is not yet fully understood. In this work, direct
laser deposition process is studied as a typical MAM process. A finite volume model is first
implemented to obtain the thermal history. Next, the thermal history is fed into a Cellular Automata
(CA) model to simulate the epitaxial and competitive growth through which the columnar grains
are formed. Nucleation is included in the model to predict the generation of equiaxed grains, and
is characterized by two nucleation parameters, the nucleation density and the critical undercooling.
The simulation results show that both the nucleation parameters and process parameters can
significantly affect the grain structure. The simulated grain structures examined on different planes
can be significantly different, revealing the complexity of the 3-dimensional grain structures in
MAM processes. | null | null | null | null | null | null |
['Fu, C.H.', 'Guo, Y.B.'] | 2021-10-18T21:41:59Z | 2021-10-18T21:41:59Z | 2014 | Mechanical Engineering | null | https://hdl.handle.net/2152/89257 | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['selective laser melting', 'FEA', 'temperature gradient', 'molten pool'] | 3-Dimensional Finite Element Modeling of Selective Laser Melting Ti-6Al-4V Alloy | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7797b9a1-095c-4a81-b8c8-0dc2b11db36b/download | University of Texas at Austin | Selective laser melting (SLM) is widely used in making three-dimensional functional parts
layer by layer. Temperature magnitude and history during SLM directly determine the molten
pool dimensions and surface integrity. However, due to the transient nature and small size of the
molten pool, the temperature gradient and the molten pool size are very challenging to measure
and control. A 3-dimensional finite element simulation model has been developed to simulate
multi-layer deposition of Ti-6Al-4V in SLM. A physics-based layer build-up approach coupled
with a surface moving heat flux was incorporated into the modeling process. The melting pool
shape and dimensions were predicted and experimentally validated. Temperature gradient and
thermal history in the multi-layer build-up process was also obtained. Furthermore, the
influences of process parameters and materials on the melting process were evaluated. | null | null | null | null | null | null |
['Sartin, B.', 'Pond, T.', 'Griffith, B.', 'Everhart, W.', 'Elder, L.', 'Wenski, E.', 'Cook, C.', 'Wieliczka, D.', 'King, W.', 'Rubenchik, A.', 'Wu, S.', 'Brown, B.', 'Johnson, C.', 'Crow, J.'] | 2021-11-02T15:25:08Z | 2021-11-02T15:25:08Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89828 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['316L', 'metal powder', 'powder reuse', 'laser powder bed fusion', 'metal additive manufacturing'] | 316L Powder Reuse for Metal Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4f71b846-370b-4e74-bf89-9434938bf7c4/download | University of Texas at Austin | Metal additive manufacturing via laser powder bed fusion is challenged by low powder
utilization. The ability to reuse metal powder will improve the process efficiency. 316L powder
was reused twelve times during this study, completing thirty-one builds over one year and
collecting 380 powder samples. The process, solidified samples, and powder were analyzed to
develop an understanding of powder reuse implications. Solidified sample characteristics were
affected more by slight process variations than by cycling of the powder. While a small percentage
of powder was greatly affected by processing, the bulk powder only observed a slight increase in
powder size. | null | null | null | null | null | null |
['Xing, Juan', 'Luo, Xianli', 'Bermudez, Juliana', 'Moldthan, Matthew', 'Li, Bingbing'] | 2021-11-04T20:35:36Z | 2021-11-04T20:35:36Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90022', 'http://dx.doi.org/10.26153/16943'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['scaffold structure', 'micro-extrusion', '3D bioprinting', '3D bioprinter'] | 3D Bioprinting of Scaffold Structure Using Micro-Extrusion Technology | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e0865ee8-2284-43dd-bfbd-079e5c0109c8/download | University of Texas at Austin | Scaffold-based techniques are a vital assistance tool to support main structure and
enhance the resolution of target structure. In this study, a custom-made micro-extrusion
bioprinting system was built and utilized to fabricate different scaffold structures such as log-pile
scaffold and two-ring scaffold. This approach showed tremendous potential because of its ability
to produce microscale channels with almost any shape. We were able to fabricate these scaffolds
by using a custom-made 3D bioprinter to print hydrogel solution, mostly composed of Pluronic
F-127, then wash away hydrogen by phosphate buffer saline (PBS) after crosslinking of main
structure. We were able to achieve the desired scaffold structure by feeding G-codes data into
user interface (Pronterface) and then translating that model into a program that utilizes a
customized programming language, which instructs the microfabrication printer nozzles to
dispense the hydrogel at specific locations. This fundamental study will be used to print
increasingly viable and complex tissue shapes with living cells. | null | null | null | null | null | null |
['Saleh, E.', 'Vaithilingam, J.', 'Tuck, C.', 'Wildman, R.', 'Ashcroft, I.', 'Hague, R.', 'Dickens, P.'] | 2021-10-21T20:24:21Z | 2021-10-21T20:24:21Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89438 | eng | 2015 International Solid Freeform Fabrication Symposium | Open | ['3D inkjet printing', 'silver ink', 'conductive structures', 'IR sintering'] | 3D Inkjet Printing of Conductive Structures using In-Situ IR sintering | Conference paper | https://repositories.lib.utexas.edu//bitstreams/02e64cac-9e16-42fd-9088-9655aab4a854/download | University of Texas at Austin | In this study we investigate the inkjet printing of a silver nanoparticle ink and the
optimization of IR sintering conditions to form 3D inkjet-printed conductive structures. The
understanding of the interaction between the silver layers and the sintering conditions are key
elements to successfully build conductive tracks in 3D.
The drop size of conductive ink on glass substrates as well as on sintered conductive film was
measured to optimize the printing resolution. The resistivity of the sintered deposition was
studied in a planar X-Y direction as well as in a vertical Z direction to analyze the effects of
stacking hundreds of silver layers in different deposition orientations.
Using the results of the optimized printing and sintering conditions, conductive tracks were
demonstrated forming simple 3D inkjet-printed structures powering electronic components. | null | null | null | null | null | null |
['Aguiar, Daniel', 'Albuquerque, Amanda', 'Li, Bingbing'] | 2021-10-28T21:40:10Z | 2021-10-28T21:40:10Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89707 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['bacterial cellulosic exopolysaccharide gel', 'droplet formation', '3D inkjetting', 'bioink', 'on-demand 3D printing', 'regenerative medicine'] | 3D Inkjetting Droplet Formation of Bacterial Cellulosic Exopolysaccharide Gel | Conference paper | https://repositories.lib.utexas.edu//bitstreams/56d89d3a-5aa8-4901-aeb7-39f7df83668f/download | University of Texas at Austin | On-demand 3D printing of scaffolds and cell-laden structures has shown promising results
that can significantly impact human welfare. The objective is to fully understand the behavior of
bacterial cellulosic exopolysaccharide gel (BCEG) as a new bioink with low toxicity and high
biocompatibility for regenerative medicine. Its possible application is to construct scaffolds that
can be used for several biomedical applications, especially tissue engineering and treatment of
critical bone defects. By using a MicroFab inkjet micro dispenser, BCEG was dispersed to create
drops on demand that can be used to fabricate scaffolds. In order to fully understand the material’s
behavior and droplet formation, we analyzed the physical and mechanical properties of the BCEG
in different concentrations (0.1% 0.5% and 1%) and characterized it by its macroscopy,
microscopy, rheology and particle size distribution. | null | null | null | null | null | null |
['Ederer, Ingo', 'Hochsmann, Rainer', 'Machan, Jurgen'] | 2018-10-05T17:26:22Z | 2018-10-05T17:26:22Z | 1995 | Mechanical Engineering | doi:10.15781/T2VQ2SW00 | http://hdl.handle.net/2152/68717 | eng | 1995 International Solid Freeform Fabrication Symposium | Open | ['CAD', '3D Printing', 'UV Curable Resins'] | A 3D Print Process For Inexpensive Plastic Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/03db90e8-7800-4a64-a33a-b2fcf4c9e7be/download | null | Many of the currently available RP-Systems are suitable for building design models of
arbitrarily shaped parts. However, most of these RP processes use sophisticated and expensive
equipment which is not well suited for an office environment. In this paper we present a
method and an experimental device for building design models by a modified 3D print process
using plastic powder and a photopolymeric binder. | null | null | null | null | null | null |
['Lipton, Jeffrey Ian', 'Angle, Sarah', 'Lipson, Hod'] | 2021-10-18T20:11:06Z | 2021-10-18T20:11:06Z | 2014 | Mechanical Engineering | null | https://hdl.handle.net/2152/89228 | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['wax', 'actuator', 'robocasting'] | 3D Printable Wax-Silicone Actuators | Conference paper | https://repositories.lib.utexas.edu//bitstreams/24111e76-38bd-405e-9c76-3be29d7fad4f/download | University of Texas at Austin | The Solid Freeform Fabrication of actuators has been an area of active development. So
far only weak polymer actuators, or small displacement piezoelectric, and pneumatic
actuators have been produced. We developed a novel material platform of silicone and wax
which can be used to make soft actuators that are thermally activated. The material is made
by mechanically mixing liquid silicone and liquid paraffin wax and cooled to create a
suspension of wax particles suspended in a silicone liquid. The resulting material expands
by up to 6% of volume when heated above the wax melting temperature. | null | null | null | null | null | null |
['Bowa, M.', 'Dean, M.E.', 'Horn, R.D.'] | 2021-11-15T22:12:40Z | 2021-11-15T22:12:40Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90289', 'http://dx.doi.org/10.26153/tsw/17210'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['3D printed electronics', '3D printing', 'additive manufacturing', 'sustainability', 'cost effectiveness'] | 3D Printed Electronics | Conference paper | https://repositories.lib.utexas.edu//bitstreams/bd23a633-415a-4d98-a800-3508d6414594/download | University of Texas at Austin | Additive manufacturing is revolutionizing the way we build and produce a plethora of
products spanning many industries. It has shown strong potential in reduced energy use,
sustainability and cost effectiveness. Exploring avenues that this technology can be utilized is key
to improve productivity and efficiencies in various applications including electronic systems and
devices manufacturing. Electronic systems and sub-systems are built using a variety of material
and processes, which require a large carbon footprint, significant waste material and high
production time. We propose the application of 3D printing technology to support an integrative
process for combining circuit board fabrication, solder mask process, electronic component pick
and place and enclosure manufacturing. The integration of these separate processes into a single
high efficiency additive manufacturing process will yield significant savings in energy use, carbon
footprint, waste product and production time and cost. | null | null | null | null | null | null |
['Delgado Camacho, Daniel', 'Clayton, Patricia', "O'Brien, William J.", 'Jung, Kee Young'] | 2021-11-09T19:27:34Z | 2021-11-09T19:27:34Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90141', 'http://dx.doi.org/10.26153/tsw/17062'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['fastener-free connections', 'additive manufacturing', '3D printing', 'material extrusion', 'polymers', 'flexural test'] | 3D Printed Fastener-Free Connections for Non-Structural and Structural Applications – An Exploratory Investigation | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b6af235f-8e6e-424c-92d3-0560a1fc51c6/download | University of Texas at Austin | The construction industry has shown increasing interest in AM technologies and has
successfully implemented various proof of concept projects using different AM processes. Much
of the research on AM in the construction industry has focused on development of new large-scale
extrusion printing systems and on development of cementitious materials for AM applications,
whereas research exploring new applications of already existing AM technologies and materials
suitable for construction applications has been scarce. This paper explores the use of existing,
small-scale material extrusion 3D printers to create fastener-free connections that could be used in
structural or non-structural applications. These connections, inspired by traditional wood joinery
and modern proprietary connections were printed using polylactic acid (PLA) material. The
flexural strength of the connections was then tested using a four-point bending test to evaluate
their potential structural performance and to identify connection types that warrant further research
in this exploratory proof of concept study. | null | null | null | null | null | null |
['Emery, B.A.', 'Revier, D.', 'Sarkar, V.', 'Nakura, M.', 'Lipton, J. I.'] | 2024-03-27T03:25:11Z | 2024-03-27T03:25:11Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124464', 'https://doi.org/10.26153/tsw/51072'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['viscous thread printing', 'additive manufacturing', 'foam', 'stiffness'] | 3D Printed Intelligently Graded Functional Stiffness Foam for Sturdier Multi Stiffness Materials | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b79a6530-9f60-453e-876a-710f992d0ad5/download | University of Texas at Austin | Foams are ubiquitous, being used in applications such as padding, insulation, and noise isolation.
Bonding different density foams together produces undesired stress concentrations and boundary
effects. Creating controlled gradients in foam properties has been a challenge for traditional and
AM processes. Here we show how to use a form of material extrusion called Viscous Thread
APrinting (VTP) to produce foams with multiple stiffnesses and continuous gradients between
different stiffnesses. We do so by varying the path speed during extrusion to control the
production of microstructures. We compare the process of producing discrete components and
those with gradients, showing that those with gradients have higher strength in plane during
tension, have no discontinuities in out of plane stiffness, and are less prone to forming cracks at
the boundaries. We demonstrate the process in thermoplastic polyurethane (TPU). | null | null | null | null | null | null |
['Bryant, Nathaniel', 'Villela, Janely', 'Villela, Juan Owen', 'Alemán, Alan', 'O’Dell, Josh', 'Ravi, Sairam', 'Thiel, Jerry', 'MacDonald, Eric'] | 2023-01-31T14:14:39Z | 2023-01-31T14:14:39Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117368', 'http://dx.doi.org/10.26153/tsw/44249'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['Additive manufacturing', '3D Printed Sand Casting', 'Binder jetting', 'Curing'] | 3D Printed Smart Mold for Sand Casting: Monitoring Pre-Pour Binder Curing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d8799ddb-6f71-4370-8f2b-4d22dc45f35e/download | null | The benefits of additive manufacturing for fabricating complex sacrificial sand molds
for geometrically-complex metal castings is revolutionizing the foundry industry driven by a
digital manufacturing paradigm. The design freedom of 3D printing allows for new mold designs
- not possible with traditional approaches - such as helical sprues, varying wall thickness to
tailor the thermal history, and spatially-varying lattice castings. However, research on the
curing time of printed molds, including the aging of printed molds, requires more exploration.
This study describes the experimental evaluation of 3D printed specimens in which embedded
environmental sensors were fully encapsulated into sand blocks during an interruption of the
binder jetting process. Subsequently, over a 28 day duration, humidity, volatile organic
compound generation, temperature and barometric pressure were captured for three
environmental treatments. Mechanical testing of standard test specimens subjected to the same
conditions was conducted. The sand structures held in high (uncontrolled) humidity and at
reduced temperature were statistically significantly weaker than a third treatment based on the
hypothesis that high humidity and/or low temperatures impede curing. The use of embedded
sensors could provide guidelines for mold and core storage conditions as well as in high-value
production to inform the minimum (for full curing) and maximum duration (mold expiration)
after printing to identify the optimal time to pour metal during the life of a printed sand mold. | null | null | null | null | null | null |
['Bryant, Nathaniel', 'Villela, Janely', 'Villela, Juan Owen', 'Alemán, Alan', 'O’Dell, Josh', 'Ravi, Sairam', 'Thiel, Jerry', 'MacDonald, Eric'] | 2023-01-27T18:08:23Z | 2023-01-27T18:08:23Z | 2022 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/117354', 'http://dx.doi.org/10.26153/tsw/44235'] | eng | 2022 International Solid Freeform Fabrication Symposium | Open | ['Additive manufacturing', '3D Printed Sand Casting', 'Binder Jetting', 'Curing'] | 3D Printed Smart Mold for Sand Casting: Monitoring Pre-Pour Binder Curing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/cb79f2dd-3610-4b68-94f4-6ad603777cee/download | null | The benefits of additive manufacturing for fabricating complex sacrificial sand molds
for geometrically-complex metal castings is revolutionizing the foundry industry driven by a
digital manufacturing paradigm. The design freedom of 3D printing allows for new mold designs
- not possible with traditional approaches - such as helical sprues, varying wall thickness to
tailor the thermal history, and spatially-varying lattice castings. However, research on the
curing time of printed molds, including the aging of printed molds, requires more exploration.
This study describes the experimental evaluation of 3D printed specimens in which embedded
environmental sensors were fully encapsulated into sand blocks during an interruption of the
binder jetting process. Subsequently, over a 28 day duration, humidity, volatile organic
compound generation, temperature and barometric pressure were captured for three
environmental treatments. Mechanical testing of standard test specimens subjected to the same
conditions was conducted. The sand structures held in high (uncontrolled) humidity and at
reduced temperature were statistically significantly weaker than a third treatment based on the
hypothesis that high humidity and/or low temperatures impede curing. The use of embedded
sensors could provide guidelines for mold and core storage conditions as well as in high-value
production to inform the minimum (for full curing) and maximum duration (mold expiration)
after printing to identify the optimal time to pour metal during the life of a printed sand mold. | null | null | null | null | null | null |
['Munguia, J.', 'Honey, T.', 'Zhang, Y.', 'Drinnan, M.', 'Di Maria, C.', 'Bray, A.', 'Withaker, M.'] | 2021-10-28T21:37:15Z | 2021-10-28T21:37:15Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89705 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['3D printing', 'home-use medical device', 'redistributed manufacturing'] | 3D Printing Enabled-Redistributed Manufacturing of Medical Devices | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4fc126ef-f044-47a6-b46b-1fec5a5519b3/download | University of Texas at Austin | Recently the home-use segment of medical devices has entered in the loop of Additive Manufacturing (AM)
enabled optimizations, this includes CPAP masks, insulin delivery packs and diagnostic tools such as urine-flow
meters. Here we analyze the supply chain provision of a specific uroflowmetry device which is originally designed
in Europe, manufactured in Asia and which has a range of distribution channels across healthcare systems. This
paper analyses the impact of various AM technologies that can enable near-patient manufacture of devices on-demand. Our analysis shows that the cost of design-changes (or product updates), when reflected on the overall
lifecycle cost, can be comparable to producing the device locally with a different supply chain arrangement.
Furthermore it is suggested that in order to fully exploit the capabilities afforded by AM, the original product’s
design features must be modified so that built-times are reduced allowing a larger 3D printing-based production
capacity. | null | null | null | null | null | null |
['McDonnell, Bill', 'Jimenez Guzman, Xavier', 'Dolack, Matthew', 'Simpson, Timothy W.', 'Cimbala, John M.'] | 2021-11-01T22:53:23Z | 2021-11-01T22:53:23Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89789 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['volatile organic compounds', 'particulate matters', 'air quality', 'maker spaces', 'college', '3D printing'] | 3D Printing in the Wild: A Preliminary Investigation of Air Quality in College Maker Spaces | Conference paper | https://repositories.lib.utexas.edu//bitstreams/a78b490b-10b0-46a1-b44f-d2eafb2e3c79/download | University of Texas at Austin | Additive manufacturing is a popular method for prototyping and manufacturing custom
parts, especially on college campuses. While there is widespread use of 3D printers as part of
many engineering classwork, there is little regulation or knowledge regarding emissions. Many
plastics, including polycarbonates, ABS, and PLA are known to emit high counts of volatile
organic compounds (VOCs) and particulate matters (PMs). This study focuses on VOC and PM
counts in several natural environments and dedicated “maker spaces” on a large college campus
to gauge the exposure that students and operators experience. Emissions were measured using a
photoionization detector and two particle sizers. The photoionization detector measured total
VOCs, and the particle size counters measured both total nanoparticles and individual micro-particles based on relative particle diameter. Measurements were taken in hourly increments and
then analyzed to determine the degree with which desktop printers emitted VOCs and PM. Our
data can be used to determine whether additional ventilation or filtration is needed when 3D
printing “in the wild” to enhance operator and bystander safety. | null | null | null | null | null | null |
['Murphy, C.', 'Kolan, K.C.R.', 'Long, M.', 'Li, W.', 'Leu, M.C.', 'Semon, J.A.', 'Day, D.E.'] | 2021-10-28T21:55:10Z | 2021-10-28T21:55:10Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89710 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['AD-MSCs', 'polycaprolactone', 'bioactive glass', '3D printing', 'bone repair'] | 3D Printing of a Polymer Bioactive Glass Composite for Bone Repair | Conference paper | https://repositories.lib.utexas.edu//bitstreams/4cffd082-c827-4f49-950a-a53a64465504/download | University of Texas at Austin | A major limitation of synthetic bone repair is insufficient vascularization of the interior
region of the scaffold. In this study, we investigated the 3D printing of adipose derived
mesenchymal stem cells (AD-MSCs) with polycaprolactone (PCL)/bioactive glass composite in
a single process. This offered a three-dimensional environment for complex and dynamic
interactions that govern the cell’s behavior in vivo. Borate based bioactive (13-93B3) glass of
different concentrations (10 to 50 weight %) was added to a mixture of PCL and organic solvent
to make an extrudable paste. AD-MSCs suspended in Matrigel was extruded as droplets using a
second syringe. Scaffolds measuring 10x10x1 mm3
in overall dimensions with a filament width
of ~500 µm and pore sizes ranging from 100 to 200 µm were fabricated. Strut formability
dependence on paste viscosity, scaffold integrity, and printing parameters for droplets of ADMSCs suspended in Matrigel were investigated. | null | null | null | null | null | null |
['Phillips, Tim', 'Allison, Jared', 'Beaman, Joseph'] | 2024-03-27T03:27:15Z | 2024-03-27T03:27:15Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124465', 'https://doi.org/10.26153/tsw/51073'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', '3D printing', 'resistance response', 'stress response'] | 3D Printing of Complex Wire Geometries for Tailored Resistance Response | Conference paper | https://repositories.lib.utexas.edu//bitstreams/89a5c9bd-8585-4111-af04-506c11fa307f/download | University of Texas at Austin | Additive manufacturing (AM) is a rapidly growing field that enables production of
complex geometries without tooling. AM has gained traction as a method of producing complex
electronic circuits not possible using traditional techniques. The method explored in this
manuscript involves post-build infiltration of conductive inks into complex channels to create
resistive elements with tunable properties. A Polyjet printer is used to enable high-precision multimaterial components with custom mechanical properties. Further, the conductive pathway
geometry can be designed to achieve different resistive responses. These properties allow for
decoupling of the stress-strain response and resistance-strain response to produce custom strain
gauges with engineered properties. | null | null | null | null | null | null |
['Jayashankar, Dhileep Kumar', 'Gupta, Sachin Sean', 'Stella, Loo Yi Ning', 'Tracy, Kenneth'] | 2021-11-18T02:09:59Z | 2021-11-18T02:09:59Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90409', 'http://dx.doi.org/10.26153/tsw/17330'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['compliant mechanism', 'passive actuation', 'additive manufacturing', 'chitosan biopolymer'] | 3D Printing of Compliant Passively Actuated 4D Structures | Conference paper | https://repositories.lib.utexas.edu//bitstreams/204bad6d-fc3e-4435-bc6d-2577224c7bd3/download | University of Texas at Austin | Additive manufacturing has begun to revolutionize the production of various physical technologies that
depend on bespoke geometry and tailored material properties for function. This includes the design of compliant
mechanisms, which rely on an integral coupling between geometric and material parameters to attain the elastic
flexibility necessary to accommodate programmed deformation. While kinetic structures with compliant parts are
typically activated by the application of a mechanical force, alternative means of achieving motion are available,
such as the use of smart, 4D, or stimuli-responsive materials which react to environmental conditions. In this
research, a combination of compliant mechanisms and water-responsive chitosan biopolymers was explored to
create flexible, programmable passive actuators, enabled by 3D printing. A set of compliant joints were modeled,
simulated, fabricated, and tested to determine the optimal design for use in the actuator. The actuator was then
iteratively tested with wetting and drying of chitosan films to invoke a specific shape change, which was analyzed
for accuracy, speed, and consistency. The study concluded with a discussion of the implications of synthesizing
compliant mechanisms, chitosan biopolymer, and additive manufacturing for next-generation adaptive structures. | null | null | null | null | null | null |
['Aguilera, Efrain', 'Ramos, Jorge', 'Espalin, David', 'Cedillos, Fernando', 'Muse, Dan', 'Wicker, Ryan', 'MacDonald, Eric'] | 2021-10-12T18:28:39Z | 2021-10-12T18:28:39Z | 2013 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88715', 'http://dx.doi.org/10.26153/tsw/15649'] | eng | 2013 International Solid Freeform Fabrication Symposium | Open | ['Additive Manufacturing', '3D printed electronics', '3D printed electromechanical devices', 'hybrid manufacturing', 'structural electronics'] | 3D Printing of Electro Mechanical Systems | Conference paper | https://repositories.lib.utexas.edu//bitstreams/69e0bbf6-0b76-4137-be71-e87f225476cb/download | University of Texas at Austin | Recent research has focused on the fabrication freedom of 3D printing to not only create
conceptual models but final end-use products as well. By democratizing the manufacturing
process, products will inevitably be fabricated locally and with unit-level customization. For 3D
printed end-use products to be profoundly meaningful, the fabrication technologies will be
required to enhance the structures with additional features such as electromechanical content. In
the last decade, several research groups have reported embedding electronic components and
electrical interconnect into 3D printed structures during process interruptions. However, to date
there appears to be an absence of fabricated devices with electromechanical functionality in which
moving parts with electronic control have been created within a single Additive Manufacturing
(AM) build sequence. Moreover, previously reported 3D printed electronics were limited by the
use of conductive inks, which serve as electrical interconnect and are commonly known for
inadequate conductivity. This paper describes the fabrication of a high current (>1 amp)
electromechanical device through a single hybrid AM build sequence using a uPrint Plus, a
relatively low cost 3D. Additionally, a novel integrated process for embedding high performance
conductors directly into the thermoplastic FDM substrate is demonstrated. By avoiding low
conductivity inks, high power electromechanical applications are enabled such as 3D printed
robotics, UAVs and biomedical devices. | null | null | null | null | null | null |
Mohammed, Mazher Iqbal | 2024-03-27T03:29:18Z | 2024-03-27T03:29:18Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124466', 'https://doi.org/10.26153/tsw/51074'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'microfluidics', '3D printing'] | 3D Printing of Passive Microfluidic Flow Mixers Using Triply Period Minimal Surface Microlattice Structures | Conference paper | https://repositories.lib.utexas.edu//bitstreams/eb5d7ce9-7d6b-43fb-8fb3-51070148af86/download | University of Texas at Austin | Microfluidics are miniaturised devices useful for precision fluid handling phases when
conducting a range of chemical reactions or biological processes. Such devices operate at
micrometre length scales, where laminar flow dominates and so interactions are limited to
diffusion between the flowing liquid interfaces unless flow is made turbulent to induce mixing.
Passive mixers are desirable for this task as they comprise geometrical features which can be
incorporated during the fabrication of such devices. Designs largely remain planar due to
traditional microfluidic manufacturing being conducted with 2.5D fabrication processes.
Additive Manufacturing now allows for passive mixers to now be realised in true 3D but have
seen limited investigation. This study explores the efficacy of several miniaturised Triply
Period Minimal Surface micro-lattice structures, formed within microfluidic channels as
turbulence inducing structures for increased mixing. We explore several lattice designs and
report on their efficacy for mixing reactions conducted during continuous flow conditions. | null | null | null | null | null | null |
['Kantareddy, S.N.R.', 'Simpson, T.W.', 'Ounaies, Z.', 'Frecker, M.'] | 2021-11-01T21:51:42Z | 2021-11-01T21:51:42Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89768 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['shape memory polymers', 'shape changing polymers', '3D printing', 'additive manufacturing'] | 3D Printing of Shape Changing Polymer Structures: Design and Characterization of Materials | Conference paper | https://repositories.lib.utexas.edu//bitstreams/9fc3e69b-ed82-4002-9dc0-d58e4bcc258d/download | University of Texas at Austin | Additive manufacturing (AM) gives engineers unprecedented design and material
freedom, providing the ability to 3D print polymer structures that can change shape.
Many of these Shape Memory Polymer (SMP) structures require multi-material
composites, and different programmed shapes can be achieved by designing and
engineering these composites to fold and unfold at different rates. To enable SMP
applications involving shape-changing geometries, it is important to have an
understanding of the relationships between intermediate shapes and the initial and final
designed shapes. To accomplish this, we investigated readily available 3D printable
polymer materials and their thermo-mechanical characteristics to create multi-member
structures. This paper demonstrates a way to generate different temporary geometric
profiles on a single 3D printed shape with the same material. This paper also includes
insights from thermo-mechanical analysis of the materials to help create multi-member
shape-changing geometries using 3D printing. | null | null | null | null | null | null |
['Chang, Shawn H.', 'Moser, Bryan R.'] | 2021-11-01T20:46:33Z | 2021-11-01T20:46:33Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89743 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', '3D printing', 'technology insertion', 'sociotechnical systems'] | 3D Printing Technology Insertion: Sociotechnical Barriers to Adoption | Conference paper | https://repositories.lib.utexas.edu//bitstreams/c8bb7aac-1309-4ff7-84ab-131069a5f725/download | University of Texas at Austin | Since the initial development of three dimensional printing (3DP) in the 1980s, companies
have relentlessly researched for applications of the technology. The potential benefit is large,
beginning with improved cost and schedule to manufacture plastic and metal articles. As such,
governments and industry from advanced economies continue to invest heavily to accelerate
3DP adoption. Amid advancements in the pillars of three dimensional printing – the
technology, material, and software – practitioners across industries are steadily deploying 3DP
in product development, prototyping, and small scale production of parts and products.
However, a large gap remains between promise and the reality of larger scale adoption. The
potential benefits, risks, and specific steps to adopt and realize the benefits are not clearly
understood, resulting in overly zealous (at risk) or overly cautious (opportunity avoided)
approaches to 3DP adoption. Traditional manufacturers rely on decades of know-how in
manufacturing practices across a large portfolio of parts, making first steps on a path to adopt
new processes more challenging.
This paper identifies the variables that complicate or impair judgement when considering the
adoption of 3DP. A systematic approach to evaluate 3DP adoption across a portfolio is needed.
A methodology is proposed to analyze the relative value of 3DP at the part and product system
level for prototyping and production. The outcome is a framework that combines part-level
feasibility with systemic benefit of cost and schedule improvements as prototyping and
production alternatives. In building this framework and in interviews with experienced
manufacturers, several key insights were gained. Part by part consideration of 3DP feasibility
is daunting, while adoption requires readiness not only of 3DP technology but also the
receiving systems and organization. By viewing 3DP insertion as a sociotechnical system
implementing the changes, attention is drawn to the tacit knowledge of critical characteristics
in existing manufacturing processes, design for manufacturing decisions embedded in existing
part assemblies, the pre-processing and post-processing capabilities available to shift 3DP
feasibilities, and the alignment of organizational learning across parts. | null | null | null | null | null | null |
Fly, David E. | 2021-10-18T20:05:10Z | 2021-10-18T20:05:10Z | 2014 | Mechanical Engineering | null | https://hdl.handle.net/2152/89225 | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['composites', 'strength-to-weight ratio', 'additive manufacturing', '3D printing'] | 3D Printing Thin Skinned Composites to Achieve the Strength-to-Weight Ratio of Aluminum | Conference paper | https://repositories.lib.utexas.edu//bitstreams/117ac7a1-b284-494b-bcb1-017b5f6eb164/download | University of Texas at Austin | Kevlar and stainless steel mesh reinforcements were added using epoxy to 3D printed ABS-M30
thin skins, thereby making a composite structure with significantly improved mechanical
properties over that of the 3D printed plastic alone. These additive manufactured composites
have a strength to weight ratio that is comparable to solid aluminum. Flexural 3-point bend tests
and Charpy Impact tests were conducted. Experiments were conducted that were designed to
characterize the influence of adding Kevlar to the composite structure and also the influence of
pre-mixing glass microspheres into the epoxy. These new additive manufactured (AM)
composites are an attractive choice to designers attempting to reduce weight because any 3D
printed shape can be reinforced in this manner. Additionally, actual production time is less than
3D printing a fully solid component. | null | null | null | null | null | null |
['Montalvo, J.I.', 'Hidalgo, M.A.'] | 2021-10-21T15:11:09Z | 2021-10-21T15:11:09Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89390 | eng | 2015 International Solid Freeform Fabrication Symposium | Open | ['3D printing', 'reinforced filament', 'natural fiber', 'reverse engineering'] | 3D Printing with Natural Fiber Reinforced Filament | Conference paper | https://repositories.lib.utexas.edu//bitstreams/997f7061-9325-40d0-a371-206958e86301/download | University of Texas at Austin | An initial study of 3d printing with compound filament using different plastic matrices and
sugar cane bagasse as the filler was conducted. In order to do this, a reverse engineering process
was made to several 3d printer extruders to determine how to change the extruder in order to be
able to print with the filament. To obtain the filament, a plastic extruder was modified to obtain a
compound filament of 1.75 mm using a 3x4 design of experiments with the factors percentage of
fiber (10% 20% 30%) and type of matrix(PE,PP,ABS,PLA). The filaments obtained were tested to
determine the mechanical properties and finally were used in a 3d printing to compare results. | null | null | null | null | null | null |
['Song, Yong-Ak', 'Park, Sehyung', 'Hwang, Kyunghyun', 'Choi, Doosun', 'Jee, Haeseong'] | 2019-02-26T17:15:15Z | 2019-02-26T17:15:15Z | 1998 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/73488', 'http://dx.doi.org/10.26153/tsw/638'] | eng | 1998 International Solid Freeform Fabrication Symposium | Open | ['mechanical strength', 'rapid tooling techniques'] | 3D Welding and Milling for Direct Prototyping of Metallic Parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2ff65214-fd4e-4373-9d70-8be62cbf4fc0/download | null | Welding has been used for the direct fabrication of metallic prototypes and prototype tools
by several research institutes. Since welding alone is not able to deliver the accuracy and the
surface quality needed for prototype tools, especially for injection molds, a combination with
conventional machining is necessary. In this paper, welding and 5-axis milling are combined
together for the direct fabrication of metallic parts. For welding, conventional CO2 arc welding
is used. Test parts with conformal cooling channels an~ undercuts demonstrate the
technological potential ofthis process combination for rapid tooling applications. | null | null | null | null | null | null |
['Vaithilingam, J.', 'Saleh, E.', 'Tuck, C.', 'Wildman, R.', 'Ashcroft, I.', 'Hague, R.', 'Dickens, P.'] | 2021-10-21T19:54:35Z | 2021-10-21T19:54:35Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89435 | eng | 2015 International Solid Freeform Fabrication Symposium | Open | ['3D inkjet printing', 'drop-on-demand', 'conductive inks', 'conductive silver', 'PEDOT:PSS', 'flexible electronics', 'stretchable electronics'] | 3D-Inkjet Printing of Flexible and Stretchable Electronics | Conference paper | https://repositories.lib.utexas.edu//bitstreams/3a4d9a27-5c78-4a2f-83b9-27cbe16b12ab/download | University of Texas at Austin | Inkjet printing of conductive tracks on flexible and stretchable materials have gained
considerable interest in recent years. Conductive inks including inks with silver nanoparticles, carbon based inks, inks containing poly (3,4-ethylenedioxythiophene) (PEDOT)
doped with polystyrene sulfonic acid (PSS) are being researched widely to obtain a printed
electronic patterns. In this study, we present drop-on-demand inkjet printing of conductive
silver and PEDOT:PSS on a flexible and stretchable substrate. Process conditions for the
inkjet printing of silver nano-particles and PEDOT:PSS were optimised and simple
geometrical patterns (straight line and sinewave tracks) were printed. Surface profile, surface
morphology and electrical resistance of the printed patterns were examined. The printed
silver patterns were observed to be highly conductive; however when stretched, the patterns
did not conduct due to the origination of cracks. The measured conductivity for the
PEDOT:PSS patterns was significantly lower than the silver patterns; however, they
remained conductive when stretched for up to 3 mm. When flexed, PEDOT:PSS remained
conductive for a lower radius of curvature (10 mm) than the silver. Among the printed
patterns, the sinewave pattern was observed to be superior for flexible electronics application. | null | null | null | null | null | null |
['Wasserfall, Florens', 'Ahlers, Daniel', 'Hendrich, Norman', 'Zhang, Jianwei'] | 2021-10-28T22:19:47Z | 2021-10-28T22:19:47Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89717 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['SMDs', 'SMD placement', 'SMD wiring', '3D-printable electronics', 'fused deposition modeling', '3D printing'] | 3D-Printable Electronics - Integration of SMD Placement and Wiring into the Slicing Process for FDM Fabrication | Conference paper | https://repositories.lib.utexas.edu//bitstreams/68a3b9d7-7cef-4c45-938b-94014b61a202/download | University of Texas at Austin | Several approaches to the integration of wires and electronic components into almost every existing additive fabrication process have been successfully demonstrated by a number of research
groups in the last years. While the pure mechanical process of generating conductive wires inside
of a printed object has proved to be feasible, the design, integration, routing and generation of
toolpaths is still a laborious manual task.
In this paper, we present a novel approach to place and wire SMDs in a three-dimensional object, based on schematics generated by conventional PCB design tools such as CadSoft EAGLE.
Routing wires in an object for FDM manufacturing requires certain knowledge about the printer’s
properties to meet the extruder characteristics, avoid non-fillable regions and electric shorts. Correspondingly for the slicing of conductive wires, the software must respect appropriate channel
widths, avoid interrupted traces and ensure proper endpoints serving as contact pads for the SMDs.
To fulfill those requirements, we implemented the design and routing software as a native extension
of an existing slicing software. The user works in a three-dimensional representation of the final
extruder toolpath, augmented by the routing information. The actual computing step is executed at
the layer level by manipulating the polygons which represent the two-dimensional object topology
and toolpath for each single layer, allowing the routing algorithm to avoid the generation of nonprintable traces. We successfully designed and printed some test objects including a force-sensor
prototype, demonstrating a significant improvement in the usability and efficiency over manual
solutions. | null | null | null | null | null | null |
['Zhang, Feng', 'Zhang, Qiangqiang', 'Grove, Weston', 'Lin, Dong', 'Zhou, Chi'] | 2021-10-28T21:00:40Z | 2021-10-28T21:00:40Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89699 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['micro-dispensing', 'directional freezing', '3D graphene oxide', '3D graphene aerogel', '3D printing'] | 3D-Printing Graphene Oxidize Based on Directional Freezing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/0ab65d4b-9d07-46ab-97e8-66a36d8ecf32/download | University of Texas at Austin | This paper aims to provide a new process that is based on micro-dispensing and directional
freezing to fabricate macro and micro controllable 3D graphene aerogel. In the first section, a
design model of the proposed system to print 3D graphene oxide is presented, and the
configurations are discussed in detail. The presented new method is contrasted to other few
graphene 3D printing process. A process planning is provided includes the complete fabrication
process and printing process. The physics mechanism behind the process is illustrated. A list of
2.5D and 3D printed samples are shown. Graphene Oxide solution is an easy to print material for
micro-dispensing device, we successfully printed GO solutions in a stable and reliable way. Our
freezing based 3D printing process matches well with freeze drying technology, which together
composes the key step for fabricating truly 3D graphene aerogel. | null | null | null | null | null | null |
['Wang, Qinguri', 'Tian, Xiaoyong', 'Huang, Lan'] | 2021-11-10T21:46:56Z | 2021-11-10T21:46:56Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90187', 'http://dx.doi.org/10.26153/tsw/17108'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['4D printing', 'continuous fiber', 'composites', 'programmable morphing'] | 4D Printing Method Based on the Composites with Embedded Continuous Fibers | Conference paper | https://repositories.lib.utexas.edu//bitstreams/3b821575-aede-49c1-8309-fb09e19e90d9/download | University of Texas at Austin | Most of the current 4D printing technologies have the following
defects: 1) the deformation shape is simple; 2) the deforming precision is
poor; 3) the deformation process is always uncontinuous. In this study, a
new 4D printing process based on the composites with embedded
continuous fibers is proposed. In this process, a bilayer structure
consisting of the top layer of continuous fibers and the bottom layer with
resin is 3D printed. Due to the different thermal expansion coefficient and
elastic modulus of the top and bottom layers, the structure will produce
bending deformation when the temperature changes. It is found that the
curvature value and the curvature direction of the composite structure can
be precisely controlled by the angle of the intersecting fibers. The
influence of fiber trajectory on curvature is studied, and then, the
controllable deformation of any developable surface is achieved. | null | null | null | null | null | null |
['Cai, Jiyu', 'Vanhorn, Austin', 'Mullikin, Casey', 'Stabach, Jennifer', 'Alderman, Zach', 'Zhou, Wenchao'] | 2021-10-21T20:20:05Z | 2021-10-21T20:20:05Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89437 | eng | 2015 International Solid Freeform Fabrication Symposium | Open | ['4D printing', 'soft robotics', 'robotic facial muscles'] | 4D Printing of Soft Robotic Facial Muscles | Conference paper | https://repositories.lib.utexas.edu//bitstreams/edf57068-d745-47f3-9fc1-929fa091461c/download | University of Texas at Austin | 4D printing is an emerging technology that prints 3D structures with smart materials that can
respond to external stimuli and change shape over time. 4D printing represents a major
manufacturing paradigm shift from single-function static structures to dynamic structures with
highly integrated functionalities. Direct printing of dynamic structures can provide great benefits
(e.g., design freedom, reduced weight, volume, and cost) to a wide variety of applications, such as
sensors and actuators, and robotics. Soft robotics is a new direction of robotics in which hard and
rigid components are replaced by soft and flexible materials to mimic actuation mechanisms in
life, which are crucial for dealing with uncertain and dynamic tasks or environments. However,
little research on direct printing of soft robotics has been reported. This paper presents a study on
4D printing of soft robotic facial muscles. Due to the short history of 4D printing, only a few smart
materials have been successfully 4D printed, such as shape memory and thermo-responsive
polymers, which have relatively small strains (~8%). In order to produce the large motion needed
for facial muscles, dielectric elastomer actuators (DEAs), operating like a capacitor with a sheet
of elastomer sandwiched by two compliant electrodes and known as artificial muscle for its high
elastic energy density and capability of producing large strains (~200%) compared to other smart
materials, is chosen as the actuator for our robotic facial muscles. In this paper, we report the first
fully 4D printed soft robotic face using DEAs. A literature review on DEAs is first presented. In
order to select the right material for our soft robotic face, the performance of different silicone-based candidate materials is tested and compared. A soft robotic face is then designed and
fabricated using the selected material to achieve facial emotions by the motion of its lip and pupils
actuated by the DEAs. This study demonstrates a 4D printed soft robotic face for the first time and
the potential of 4D printing of soft robotics. | null | null | null | null | null | null |
['Kapil, Sajan', 'Negi, Seema', 'Joshi, Prathamesh', 'Sonwane, Jitendra', 'Sharma, Arun', 'Bhagchandani, Ranjeet', 'Karunakaran, K.P.'] | 2021-11-04T18:08:54Z | 2021-11-04T18:08:54Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/89992', 'http://dx.doi.org/10.26153/16913'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['hybrid layered manufacturing', 'rapid prototyping', '5-axis cladding', '5-axis slicing', 'non-planar slicing'] | 5-Axis Slicing Methods for Additive Manufacturing Process | Conference paper | https://repositories.lib.utexas.edu//bitstreams/0b4a3b44-b809-494a-a216-fd556fd90d0a/download | University of Texas at Austin | In metallic Additive Manufacturing (AM) processes such as Hybrid Layered
Manufacturing (HLM), it is difficult to remove the support material used for realizing the
overhanging/undercut features. Multi-axis kinematics can be used to eliminate the requirement
of the support mechanism. In this work, two slicing methods have been proposed which utilize
the benefits of multi-axis kinematics to eliminate the support mechanism. In the first method,
planar slicing is used and the overhanging/undercut features are realized while keeping the
growth of the component in the conventional Z-direction. In the second method, non-planar
slicing is used, and the growth of the component need not necessarily be in the Z-direction; it
can also be conformal to the selected feature of the component. Both these methods are
explained through a case study of manufacturing an impeller by the HLM process. | null | null | null | null | null | null |
['Chatham, Camden A.', 'Benza, Donald W.'] | 2024-03-25T21:58:45Z | 2024-03-25T21:58:45Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124309', 'https://doi.org/10.26153/tsw/50917'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['manufacturing', 'interface', 'engineering', 'polymer', '2023 Solid Freeform Fabrication Symposium'] | A comparison of mechanical properties from natural and process-induced interfaces in filament extrusion AM of polymer blends | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d7683458-5b04-482f-a8cc-dfbbbfcdd6c8/download | University of Texas at Austin | Polymer blends are commonly tuned for specific applications to achieve desired properties
otherwise inaccessible or prohibitively expensive to obtain via homopolymers. The interfacial
characteristics of the polymer A-polymer B interface and resultant domain sizes govern key
performance properties. Micro- and meso-scale morphology forms through the interplay of
surface forces between the polymers and between each polymer and the surrounding atmosphere.
Analogously, the layer-layer and road-road interfaces of material extrusion (MEX) additive
manufacturing (AM) govern key performance properties of printed parts. This work explores the
effect of layer height on the thermomechanical performance of polystyrene (PS)-polycarbonate
(PC) blends. Filament is prepared from a 50/50 weight ratio of the two polymers and compared
against dual-nozzle printing where every layer alternates between PS or PC homopolymer forming
a part with an overall 50/50 polymer ratio. Typical indicators of polymer blend compatibility are
also studied. | null | null | null | null | null | null |
['Ahmad, Nabeel', 'Bidar, Alireza', 'Ghiaasiaan, Reza', 'Gradl, Paul R.', 'Shao, Shuai', 'Shamsaei, Nima'] | 2024-03-25T22:54:42Z | 2024-03-25T22:54:42Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124329', 'https://doi.org/10.26153/tsw/50937'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'L-PBF', 'LP-DED', 'WAAM', 'Inconel 718'] | A Comparison of Microstructure and Mechanical Performance of Inconel 718 Manufactured via L-PBF, LP-DED, and WAAM Technologies | Conference paper | https://repositories.lib.utexas.edu//bitstreams/dabc9dba-11ca-45d3-9c50-f5bcb709245a/download | University of Texas at Austin | The microstructure and mechanical properties of additively manufactured (AM) alloys can be significantly
affected by variations in cooling rates, resulting from different process conditions across different additive
manufacturing (AM) platforms. Therefore, it is crucial to understand the effect of manufacturing process on the
microstructure and mechanical properties of AM Inconel 718. This study examines three AM processes: laser
powder bed fusion, laser powder directed energy deposition, and wire arc additive manufacturing. Results show
that fully heat treated laser powder bed fused (L-PBF) and wire arc additively manufactured (WAAM) Inconel
718 specimens exhibit higher strength compared to laser powder directed energy deposited (LP-DED) ones due
to finer grain structure in L-PBF and retained dendritic microstructure in WAAM. The ductility in LP-DED
Inconel 718 was slightly higher compared to WAAM and L-PBF due to relatively small carbide size, which causes
stress concentration in a small material volume, leading to delayed fracture. | null | null | null | null | null | null |
['Caballero, K.', 'Medrano, V.A.', 'Arrietam E.', 'Merino, J.', 'Ruvalcaba, B.', 'Ramirez, B.', 'Diemann, J.', 'Murr, L.E.', 'Wicker, R.B.', 'Godfrey, D.', 'Benedict, M.', 'Medina, F.'] | 2024-03-25T22:58:06Z | 2024-03-25T22:58:06Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124330', 'https://doi.org/10.26153/tsw/50938'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['AlSi7Mg alloy', 'laser powder bed fusion', 'EOS M290 system', 'SLM 280HL system', 'heat treatments', 'microindentation hardness', 'mechanical properties analysis'] | A comparison of the mechanical behavior of AlSi7Mg alloy produced through additive manufacturing and subjected to different heat treatment and aging conditions | Conference paper | https://repositories.lib.utexas.edu//bitstreams/47020d4e-3f86-4e78-a12e-e716f20fd7a1/download | University of Texas at Austin | The versatility and adaptability of Aluminum F357 (AlSi7Mg) make it a popular material in the
aerospace and defense industries. In this study, two different laser powder bed fusion systems,
EOS M290, and SLM 280HL were used to create specimens of Aluminum F357. These
specimens were subjected to five different heat treatments: As-built, stress relief (SR), hot
isostatic pressing (HIP), T6, and HIP+T6) as per ASTM F3318-18 standard. The printed
specimens were then reduced to tensile bars through machining and tested for mechanical
properties as per ASTM E28 using an MTS Landmark tensile testing system. In addition to the
mechanical behavior analysis, the study used a JEOL JSM-IT500 SEM to observe and document
the fracture produced by the tensile test and a Qness 30 CHD Master+ microhardness testing
system to obtain hardness (HV) values of the alloy. The results showed that specimens fabricated
in the Z direction had a tendency for higher yield strengths of approximately 225 MPa and
although these results were similar between LPBF systems some variances can still be seen.
However, these differences between the LPBF systems were observed to be partially mitigated
by heat treatments. In conclusion, this study highlights the significance of heat treatment on the
mechanical properties of Aluminum F357. The results provide valuable information for the
aerospace and defense industries to optimize their processes and produce high-quality
components. The compatibility of LPBF system fabrication and the mitigation of differences
observed between LPBF machines by heat treatments, further demonstrate the potential of this
method for producing high-quality Aluminum F357 components. | null | null | null | null | null | null |
['Liao, A.', 'Behera, D.', 'Cullinan, M.A.'] | 2024-03-25T22:59:58Z | 2024-03-25T22:59:58Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124332', 'https://doi.org/10.26153/tsw/50940'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['laser sintering', 'microscale', 'additive manufacturing'] | A NOVEL COATING METHOD USED TO ENABLE MULTILAYER STRUCTURES WITH MICROSCALE SELECTIVE LASER SINTERING | Conference paper | https://repositories.lib.utexas.edu//bitstreams/d62c88c0-8d13-4085-a496-adb77aa3dd00/download | University of Texas at Austin | The microscale selective laser sintering process (µSLS) is an additive manufacturing technique that
enables the creation of metal features with sub-5 µm in-plane resolution. In this process, a layer of metal
nanoparticle ink is deposited onto a substrate and positioned beneath an optical subsystem with a
nanopositioning stage. Using a digital micromirror device, a laser is spatially modulated to selectively heat up
particles in desired regions to cause sintering. The substrate is then moved to a coating station where a new layer
of nanoparticle ink is applied atop the sintered features. Initially, the slot-die coating process was adopted as
the recoating method for this technique. However, due to challenges with depositing consistent ink thickness
across the recoated part and limitations with the minimum layer thickness achievable, a new approach inspired
by blade coating has been developed to achieve layer thicknesses of less than 1 µm. | null | null | null | null | null | null |
['Barroi, A.', 'Schwarz, N.', 'Hermsdorf, J.', 'Bielefeld, T.', 'Kaierle, S.'] | 2024-03-26T22:59:55Z | 2024-03-26T22:59:55Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124438', 'https://doi.org/10.26153/tsw/51046'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'laser wire', 'titanium', 'gas chamber'] | A small volume, local shielding gas chamber with low gas consumption for Laser Wire Additive Manufacturing of bigger titanium parts | Conference paper | https://repositories.lib.utexas.edu//bitstreams/16535e1d-86a5-4f46-a466-86d85ef8debc/download | University of Texas at Austin | This paper shows how additive manufacturing of large size titanium parts can be achieved by means of a
mobile shielding gas chamber, without the consumption of excessive amounts of shielding gas. While welding, the
oversized cover of the chamber can be slid to the sides without opening it. The laser head is only partly inserted
into the chamber through the cover. This enables a small sized chamber and allows a quick filling with argon.
Since the chamber has a low leakage, only small amounts of argon (5 l/min) are needed to maintain a sufficient
welding atmosphere with less than 300 ppm oxygen. For large sized parts, the chamber can be repositioned on the
substrate. It has flexible parts which can be fit to the already welded structures that otherwise would prevent the
chamber from being put flat on the substrate. The limited build space inside the chamber requires a new
welding strategy, which is suggested. | null | null | null | null | null | null |
['Dwivedi, Rajeev', 'Dwivedi, Indira', 'Panwar, Arihant', 'Dwivedi, Bharat'] | 2024-03-26T20:32:23Z | 2024-03-26T20:32:23Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124398', 'https://doi.org/10.26153/tsw/51006'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['rocket', 'nozzle', 'additive manufacturing'] | A Solid Free Form Fabrication Equipment to Manufacture Axisymmetric Parts with Improved Surface Quality | Conference paper | https://repositories.lib.utexas.edu//bitstreams/23219f6e-7166-4aea-b2c3-dab7969e68b5/download | University of Texas at Austin | Competitive and Hobby grade Rocket makers quite often build custom nozzles. Solid freeform
fabrication is most natural choice for Manufacturing of the Nozzles. Different geometries can be
quickly manufactured and tested. However, staircase effect and limited accuracy of 2-1/2 based
deposition prevents the design intent from fabrication. Additionally, using different blends of ceramic
and sustaining the geometry during curing becomes challenging. This research presents a unique
3D printing system that dispenses ceramic to enable manufacturing of axi-symmetric parts as
continuous bead. Relative motion of the material dispenser and rotational substrate as well as
unique path planning enables a continually sculpted surface to reduce the staircase effects. | null | null | null | null | null | null |
['Ko, S.', 'Sagawa, T.', 'Yamagata, Y.', 'Aoki, S.', 'Abe, T.'] | 2024-03-26T23:02:23Z | 2024-03-26T23:02:23Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124439', 'https://doi.org/10.26153/tsw/51047'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['wire arc additive manufacturing', 'WAAM', 'test artifact', 'inspection process', 'sphere'] | A SPHERICAL TEST ARTIFACT TO EVALUATE THREE-DIMENSIONAL FORM ACCURACY FOR WIRE ARC ADDITIVE MANUFACTURING | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8ebe3882-a6e7-4a62-97e3-911878393aed/download | University of Texas at Austin | Additive manufacturing, including the wire arc additive manufacturing (WAAM), is gradually
gaining attraction, and providing benefits in the aerospace and construction industries. In both
industries, large-scale manufacturing capability and quality consistency of manufactured 3D parts
are crucial. As part of quality evaluation, test artifacts for the geometric capability assessment are
specified in ISO/ASTM52902-2019(E). On the other hand, the test artifact for curved wall is left
undefined. This paper proposes a spherical shell shape as a representative of three-dimensional
shapes that are supportless and feature large overhangs, for testing the geometric capability of a
WAAM equipment. A mechanical configuration and deposition strategy are considered, which
owns the potential to universally applying for depositing large-scale parts. A quality evaluation
process for the sphere deposition was also described and experimentally demonstrated. | null | null | null | null | null | null |
['Jalui, S.S.', 'Spurgeon, T.J.', 'Jacobs, E.R.', 'Chatterjee, A.', 'Stecko, T.', 'Manogharan, G.P.'] | 2021-12-07T18:48:33Z | 2021-12-07T18:48:33Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90755', 'http://dx.doi.org/10.26153/tsw/17674'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['laser-powder bed fusion', 'additive manufacturing', 'surface roughness', 'abrasive flow machining', 'micro-CT scanning', 'hybrid AM'] | Abrasive Flow Machining of Additively Manufactured Titanium: Thin Walls and Internal Channels | Conference paper | https://repositories.lib.utexas.edu//bitstreams/e59c70a1-7a26-4313-9c9f-1c783c890072/download | University of Texas at Austin | Metal additive manufacturing using Laser-Powder Bed Fusion (L-PBF) technique has enabled
the metal manufacturing industry to use design tools with increased flexibility such as freeform internal
channel geometries that benefit thermofluidic applications such as heat exchangers. A primary drawback
of the L-PBF process is the as-built surface roughness, which is a critical factor in such surface-fluidic
applications. In addition, complex internal channel geometries cannot be post-processed through traditional
finishing and polishing methods, and require advanced finishing processes such as Abrasive Flow
Machining (AFM). In this original study, the effects of AM design including geometrical changes at the
inlets, internal channel and wall thickness of thin features are experimentally studied on Ti64 L-PBF parts.
A novel surface roughness inspection technique using micro-CT data is also presented. The internal
channels with larger dimensions underwent 40% improvement in surface roughness with no statistically
significant change in diameter whereas the channels with smaller dimensions and bends had a 38%
improvement in surface roughness accompanied by a 6% increase in diameter. While there was as much
as 30% improvement in surface roughness values, the thin walls less than 0.4 mm in dimension were
deformed under the AFM pressure after just 5 cycles. | null | null | null | null | null | null |
['Karunakaran, Rakeshkumar', 'Ortgies, Sam', 'Green, Ryan', 'Barelman, William', 'Kobler, Ian', 'Sealy, Michael'] | 2021-12-01T21:19:08Z | 2021-12-01T21:19:08Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90616', 'http://dx.doi.org/10.26153/tsw/17535'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['magnesium', 'corrosion', 'powder bed fusion', 'fracking'] | Accelerated Corrosion Behavior of Additive Manufactured WE43 Magnesium Alloy | Conference paper | https://repositories.lib.utexas.edu//bitstreams/df537715-f19f-405b-84aa-0b393b278dc0/download | University of Texas at Austin | Magnesium alloys are capable of withstanding the high temperatures and pressures needed
in oil and gas fracking operations followed by rapid and complete dissolution in days. Dissolvable
magnesium plugs are used in fracking to enable longer lateral wellbores by eliminating mill-outs
and the associated debris clogging. To increase extraction efficiency, the key technical challenge
is determining how to increase the strength of a high corrosion rate magnesium device that enables
higher pressures while maintaining high corrosion rates. Topologically modified dissolvable plugs
fabricated by additive manufacturing is proposed as a solution to fabricate high strength and high
corrosion rate fracture plugs. Corrosion of magnesium is dependent on surface area exposed to
corrosive media and is easily manipulated by additive manufacturing. This study highlights the
development of optimal powder bed fusion process parameters for WE43 magnesium alloy and
investigates the corrosion behavior of printed WE43 in a salt solution concentrated with sodium
bicarbonate to initiate highly accelerated corrosion. Printed WE43 corroded three times faster than
an as-rolled sample and was driven by the mechanical and materials properties formed by printing. | null | null | null | null | null | null |
['Pintat, T.', 'Greul, M.', 'Greulich, M.'] | 2018-10-04T19:57:36Z | 2018-10-04T19:57:36Z | 1995 | Mechanical Engineering | doi:10.15781/T21C1V11T | http://hdl.handle.net/2152/68708 | eng | 1995 International Solid Freeform Fabrication Symposium | Open | ['SEM', 'postprocessing', 'electrodeposition'] | Accuracy and Mechanical Behavior of Metal Parts Produced by Lasesrintering | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8417d67b-d4f4-4b3f-bdb6-18a97082d69b/download | null | The work shows the mechanical properties of direct laser-sintered metal parts. The parts were tested after sintering and after an infiltration. Furthermore the accuracy of the parts was measured. Micrographs of the parts show the microstructure of the copper-nicker-tin alloy. The achievable complexity of parts is demonstrated by examples. An overview of future activities is given. | null | null | null | null | null | null |
['Eosoly, S.', 'Ryder, G.', 'Tansey, T.', 'Looney, L.'] | 2020-03-10T16:09:47Z | 2020-03-10T16:09:47Z | 2007 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80221', 'http://dx.doi.org/10.26153/tsw/7240'] | eng | 2007 International Solid Freeform Fabrication Symposium | Open | selective laser sintering | Accuracy and Mechanical Properties of Open-Cell Microstructures Fabricated by Selective Laser Sintering | Conference paper | https://repositories.lib.utexas.edu//bitstreams/6815d665-f567-474c-8c55-54aba7a0b24e/download | null | This paper investigates the applicability of selective laser sintering (SLS) for the manufacture of
scaffold geometries for bone tissue engineering applications. Porous scaffold geometries with
open-cell structure and relative density of 10-60 v% were computationally designed and
fabricated by selective laser sintering using polyamide powder. Strut and pore sizes ranging from
0.4 - 1 mm and 1.2 -2 mm are explored. The effect of process parameters on compressive
properties and accuracy of scaffolds was examined and outline laser power and scan spacing
were identified as significant factors. In general, the designed scaffold geometry was not
accurately fabricated on the micron-scale. The smallest successfully fabricated strut and pore size
was 0.4 mm and 1.2 mm, respectively. It was found that selective laser sintering has the potential
to fabricate hard tissue engineering scaffolds. However the technology is not able to replicate
exact geometries on the micron-scale but by accounting for errors resulting from the diameter of
the laser and from the manufacturing induced geometrical deformations in different building
directions, the exact dimensions of the manufactured scaffolds can be predicted and controlled
indirectly, which corresponds favorably with its application in computer aided tissue engineering. | null | null | null | null | null | null |
['Volpato, Neri', 'Childs, Thomas H.C.', 'Pennington, Alan de'] | 2019-09-23T16:14:16Z | 2019-09-23T16:14:16Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/75953', 'http://dx.doi.org/10.26153/tsw/3052'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Shelling | Accuracy Effects of Shelling a Part in the SLS Process 306 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/ba27c435-11ae-4723-b417-55134991338d/download | null | In order to reduce SLS process time in the manufacture of a mould insert, the idea of shelling the geometry of the insert has been tested. Some shelling strategies have been successful with the RapidToolTM process, proving the feasibility of the idea. It has been observed in the tests, for both polymer and RapidSteel2.0TM materials, that size accuracy, particularly of small features in the scanning (X) direction, depends on vector length (VL). When a sudden change in VL occurs, this leads to steps on the sintered surface. This paper presents both experimental observations of this and simulation results from a finite element model. | null | null | null | null | null | null |
['Gregorian, A.', 'Elliott, B.', 'Navarro, R.', 'Ochoa, F.', 'Singh, H.', 'Monge, E.', 'Foyos, J.', 'Noorani, R.', 'Fritz, B.', 'Jayanthi, S.'] | 2019-10-09T16:13:53Z | 2019-10-09T16:13:53Z | 2001 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/76150', 'http://dx.doi.org/10.26153/tsw/3239'] | eng | 2001 International Solid Freeform Fabrication Symposium | Open | Prototyping | Accuracy Improvement in Rapid Prototyping Machine (FDM-1650) | Conference paper | https://repositories.lib.utexas.edu//bitstreams/2a18cbee-5035-40e8-856f-efb7fa2a26d7/download | null | Over the past few years, improvements in equipment, materials, and processes have enabled
significant improvements in the accuracy of Fused Deposition Modeling (FDM) technology.
This project will investigate the present in-plane accuracy of a particular FDM machine using the
benchmark “User Part” developed by the North American StereoLithography User Group
(NASUG) and show the effect of optimal Shrinkage Compensation Factors (SCF) on the
accuracy of the prototyped parts.
The benchmark parts were built on the FDM-1650 prototyping machine and a total of 46
measurements were taken in the X and Y planes using a Brown & Sharpe Coordinate Measuring
Machine (CMM). The data was then analyzed for accuracy using standard formulas and
statistics, such as mean error, standard deviation, residual error, rms error, etc. The optimal SCF
for the FDM-1650 machine was found to be 1.007 or 0.7%. | This work was funded by a National Science Foundation (NSF) grant to Loyola Marymount
University for their Research Experience for Undergraduates program. | null | null | null | null | null |
['Pang, Thomas H.', 'Guertin, Michelle D.', 'Nguyen, Hop D.'] | 2018-10-10T15:33:37Z | 2018-10-10T15:33:37Z | 1995 | Mechanical Engineering | doi:10.15781/T2X92238B | http://hdl.handle.net/2152/68755 | eng | 1995 International Solid Freeform Fabrication Symposium | Open | ['Rapid prototyping', 'SLA', 'stereolithography'] | Accuracy of Stereolithography Parts: Mechanism and Modes of Distortion for a "Letter-H" Diagnostic Part | Conference paper | https://repositories.lib.utexas.edu//bitstreams/fa40a594-bdda-44c1-9ce7-6b68228e4b42/download | null | Rapid Prototyping and Manufacturing (RP&M) users need to compare the accuracy of various
commercially available RP&M materials and processes. A good diagnostic test for both material and the
fabrication process involves a 4-inch long "letter-H" diagnostic part. This diagnostic part, known as "H-4", was
developed to measure the inherent dimensional characteristics ofvarious RP&M build materials. It is also less
dependent on the calibration status of particular RP&M machines, and is excellent for the purpose of generating
simple but meaningful accuracy information, which can be used to further understand the mechanism and the
modes of distortion in RP&M materials. H-4 parts were prepared and built in Stereolithography Apparatus (SLA)
using Ciba-Geigy epoxy based resins SL 5170 and SL 5180, and results were compared to acrylate based SL 5149.
Experimental data involving the magnitude, mechanism, and the modes of distortion for these three resins are
analyzed in this paper. | null | null | null | null | null | null |
['Crockett, R. S.', 'Horvath, T.', 'Koch, M.', 'Yang, M.'] | 2020-02-17T15:43:02Z | 2020-02-17T15:43:02Z | 2004 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/80014', 'http://dx.doi.org/10.26153/tsw/7039'] | eng | 2004 International Solid Freeform Fabrication Symposium | Open | Solid Freeform Fabrication | Accurate Heart Model for Pacemaker Development in SFF | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7ecc8ca7-c7ee-4ef8-b2df-61b62028610d/download | null | Medical imaging combined with SFF techniques were used to create detailed CAD and physical
heart models for commercial development of Pacemakers. Using a data set of 2D optical slice
images of the human heart at 1mm spacing obtained from the Visible Human Project, a 3D CAD
model was constructed by masking the features of interest in each slice. Normals on the
resulting .stl file were inverted to create a single-piece mold, which was built in starch using 3D
Printing. Flexible silicone was cast into this mold, and the starch was dissolved away to produce
the final physical heart model. The resulting model simulates the mechanical properties of an
actual heart, with medically accurate internal and external details including major veins &
arteries, coronary sinus, etc. | null | null | null | null | null | null |
Levi, Heim | 2018-04-16T17:40:17Z | 2018-04-16T17:40:17Z | 1991 | Mechanical Engineering | doi:10.15781/T2513VC7R | http://hdl.handle.net/2152/64312 | eng | 1991 International Solid Freeform Fabrication Symposium | Open | ['rapid prototyping', 'Solid Ground Curing Technology', 'stereolithography'] | Accurate Rapid Prototyping | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b2e4f5af-9514-4e14-b1aa-d8ab1316fe14/download | null | The first stage of Rapid Prototyping life cycle as a new technology
in the marketplace is gradually ending, and the second stage has
already started. Many new vendors have introduced their products in
this field, utilized different, new technologies or improvements of
the existing ones. The first introduction of the RP concept and
Stereolithography created a stunning impression in the marketplace.
After a couple of years, as customers and users have gained much
experience and understanding or RP technology, the first enthusiasm
started making way to more serious and demanding approach. This is
very well reflected in the thorough evaluations of the different
technologies available today in the marketplace, done by customers
looking for a technology that will best fit their needs. This is
actually why most of us are here today. | null | null | null | null | null | null |
['Loney, D.A.', 'Zhou, W.', 'Rosen, D.W.', 'Degertekin, F.L.', 'Fedorov, A.G.'] | 2021-09-30T13:33:59Z | 2021-09-30T13:33:59Z | 2010 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88240', 'http://dx.doi.org/10.26153/tsw/15181'] | eng | 2010 International Solid Freeform Fabrication Symposium | Open | ['acoustics', 'Additive Manufacturing via Microarray Deposition', 'ultrasonic atomizer', 'high viscosity fluid injection', '3D inkjet manufacturing'] | Acoustic Analysis of Viscous Fluid Ejection Using Ultrasonic Atomizer | Conference paper | https://repositories.lib.utexas.edu//bitstreams/3b9a63a6-f12b-4c12-bda1-4baac0a43cca/download | University of Texas at Austin | The acoustics of the Additive Manufacturing via Microarray Deposition (AMMD) system
based on a ultrasonic atomizer is investigated for printing high viscosity fluids for 3D inkjet
manufacturing applications. The ultrasonic atomizer incorporates a piezoelectric transducer, a
material reservoir, and a silicon micromachined array of acoustic horn structures as ejection
nozzles. When driven at the resonance frequencies of the fluid cavity, the nozzle geometry
focuses the acoustic waves resulting in a locally increased pressure gradient at the nozzle apex.
Previously, AMMD has demonstrated successful ejection of fluids with viscosity as high as 3000
mN-s/m2, overcoming the viscosity limitations traditionally associated with piezoelectric droplet
formation. However, the physics of ejection of such high-viscosity fluids is not well understood.
This work focuses on understanding the acoustics of the AMMD system through complimentary
simulations and experimental characterization. Specifically, ANSYS finite element software was
used to model acoustic wave attenuation due to viscosity inside the material cavity and its
implication on the pressure gradient at nozzle apex, which drives the fluid ejection.
Additionally, the affect of fluid attenuation on cavity resonance modes, both the frequency and
the quality factor, is characterized for fluids of a large variation range in viscosity. Finally,
preliminary guidelines for improved design and efficient operation of the AMMD system are
formulated based on an insight into a device’s acoustic behavior with high viscosity fluids. | null | null | null | null | null | null |
['Kouprianoff, D.', 'Luwes, N.', 'Yadroitsava, I.', 'Yadroitsev, I.'] | 2021-11-15T21:53:40Z | 2021-11-15T21:53:40Z | 2018 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90283', 'http://dx.doi.org/10.26153/tsw/17204'] | eng | 2018 International Solid Freeform Fabrication Symposium | Open | ['online monitoring', 'online detection', 'acoustic emission', 'fusion defect', 'balling effect', 'single tracks', 'metal laser powder bed fusion'] | Acoustic Emission Technique for Online Detection of Fusion Defects for Single Tracks During Metal Laser Powder Bed Fusion | Conference paper | https://repositories.lib.utexas.edu//bitstreams/34ddc76c-8dca-4f50-940a-5a7e46a3e6c1/download | University of Texas at Austin | One of the main drawbacks of laser based powder bed fusion, is lack of fusion
between tracks due to non-optimal input process parameters, scanning and building
strategies and/or inhomogeneity in the delivered powder layer. Unstable geometrical
characteristics of single tracks and high roughness of the powder layer can cause porosity in
3 dimensional printed parts. In this study a non-destructive online monitoring technique,
using acoustic emission was utilized to determine lack of fusion and balling effect of single
tracks. This phenomenon was simulated by using an increased powder layer thickness. Short
Time Fourier Transform was used as a tool for analysis of the acoustic behaviour of the
system and it was compared with the acoustic emission (AE) recorded during processing of
single tracks. | null | null | null | null | null | null |
['Khurana, Jivtesh B.', 'Dinda, Shantanab', 'Simpson, Timothy W.'] | 2021-11-04T14:39:17Z | 2021-11-04T14:39:17Z | 2017 | Mechanical Engineering | null | https://hdl.handle.net/2152/89971 | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['active z printing', 'part strength', '3D printing', 'fused filament fabrication', 'design of experiments'] | Active - Z Printing: A New Approach to Increasing 3D Printed Part Strength | Conference paper | https://repositories.lib.utexas.edu//bitstreams/a7ebc85b-565f-4137-9864-baca0e739b29/download | University of Texas at Austin | Research suggests that topology and build parameters in Fused Filament Fabrication (FFF)
play a vital role in determining mechanical properties of parts produced by this technique. In
particular, the use of 2D layers printed parallel to the build surface produces high anisotropy in
parts making them the weakest when loaded perpendicular to the layer interfaces. We investigate
a novel approach that uses non-planar 3D layer shapes - Active Z printing, to improve mechanical
strength through alignment of localized stress tensors parallel to the deposition paths. Sinusoidal
layer shapes are used with varying amplitude, frequency, and orientation. Design of experiments
is performed to correlate effect of varying shape and orientation of sinusoidal layer shapes on
flexural strength of parts. Based on this, the results are used to decide parameters to be studied
further and characterize their effect on the strength of parts. | null | null | null | null | null | null |
['Saari, M.', 'Galla, M.', 'Cox, B.', 'Richer, E.', 'Krueger, P.', 'Cohen, A.'] | 2021-10-19T17:40:27Z | 2021-10-19T17:40:27Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89306 | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['Fiber Encapsulation Additive Manufacturing', 'electromechanical devices', 'active devices', 'device fabrication'] | Active Device Fabrication Using Fiber Encapsulation Additive Manufacturing | Conference paper | https://repositories.lib.utexas.edu//bitstreams/06b4b2b7-fdce-4e28-b6d3-4280f5b6ec34/download | University of Texas at Austin | Fiber Encapsulation Additive Manufacturing (FEAM) is a novel solid freeform
fabrication process in which a fiber and a matrix are co-deposited simultaneously within a single
printer along straight and curved 2-D and 3-D paths. Using a FEAM approach in which the fiber
is a metal wire and the matrix is a thermoplastic polymer, simple electromechanical devices such
as voice coils, inductive sensors, and membrane switches have been successfully produced. This
paper will present an overview of the FEAM process, describe several fabricated devices, and
discuss recent developments in controllably stopping and starting the wire, and in creating
electrical junctions between individual wires, which together enable much more complex devices
to be made. | null | null | null | null | null | null |
['Adams, Gavin', 'Meisel, Nicholas'] | 2024-03-26T16:53:19Z | 2024-03-26T16:53:19Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124371', 'https://doi.org/10.26153/tsw/50979'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['continuous carbon fiber', '3D printing', 'DfAM', 'additive manufacturing'] | ADAPTING A DESIGN FOR ADDITIVE MANUFACTURING WORKFLOW TO ACCOUNT FOR CONTINUOUS CARBON FIBER REINFORCED PARTS | Conference paper | https://repositories.lib.utexas.edu//bitstreams/dbfa8d81-6e41-46ce-a646-31e62981f667/download | University of Texas at Austin | The use of continuous carbon fiber (CCF) reinforcement in material extrusion 3D printing has the
potential to revolutionize the material extrusion field of additive manufacturing. Notably, the
Markforged X7 system utilizes this CCF reinforcement with the aim to produce parts with
mechanical results rivaling or surpassing those of aluminum. However, due to certain constraints
with the deposition of CCF in material extrusion parts, such as an inability for CCF to be deposited
throughout layers in the Z-direction, traditional design for additive manufacturing (DfAM)
techniques need to be reevaluated. This paper will explore (1) how existing DfAM considerations
(e.g., topology optimization, functional integration, minimum feature size, etc.) can be tailored to
CCF and (2) how an existing DfAM workflow can be adapted to account for manufacturing
limitations specific to the deposition of CCF. The research is demonstrated through a hoist sling
case study, which highlights the importance of considering fiber orientation and routing in the
design stage to ensure accurate CCF reinforcement and achieve ideal mechanical results relative
to the loads associated with the part. The result is an initial, potentially valuable workflow for
designing CCF parts to be created using AM. | null | null | null | null | null | null |
Boudreaux, J.C. | 2018-11-16T14:47:59Z | 2018-11-16T14:47:59Z | 1996 | Mechanical Engineering | doi:10.15781/T2V40KJ88 | http://hdl.handle.net/2152/70282 | eng | 1996 International Solid Freeform Fabrication Symposium | Open | ['SLA', 'SFF', 'SLS'] | An Adaptive Control Architecture for Freeform Fabrication | Conference paper | https://repositories.lib.utexas.edu//bitstreams/cbf0c01a-b372-4c8b-8650-15fe3aea5261/download | null | null | null | null | null | null | null | null |
['Vouzelaud, F.A.', 'Bagchi, A.'] | 2018-04-19T18:36:20Z | 2018-04-19T18:36:20Z | 1992 | Mechanical Engineering | doi:10.15781/T2QB9VP36 | http://hdl.handle.net/2152/64411 | eng | 1992 International Solid Freeform Fabrication Symposium | Open | ['Department of Mechanical Engineering', 'FFF', 'free form frabrication'] | Adaptive Laminated Machining for Prototyping of Dies and Molds | Conference paper | https://repositories.lib.utexas.edu//bitstreams/21a83f11-db41-490f-8a01-3a16686bdbdf/download | null | Adaptive laminated machining is the fusion of slicing a solid model into layers and producing parts by CNC
milling machines. Unlike other solid freeform fabrication processes which create the part by addition of
material, adaptive laminated machining can create solid parts by selectively removing in layers. The
research issues and practical limitations on shape and manufacturability are thus different from other
processes. However, the biggest advantage is the ability to obtain a solid metal part such as a die or a
mold directly. In this paper, the concept of this technique, and initial results and parts produced in Clemson
will be presented. In addition, future research needs and issues will be discussed. | null | null | null | null | null | null |
Chalavadi, Pradeep | 2024-03-27T03:35:56Z | 2024-03-27T03:35:56Z | 2023 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/124469', 'https://doi.org/10.26153/tsw/51077'] | en_US | 2023 International Solid Freeform Fabrication Symposium | Open | ['adaptive meshing', 'octree data structure', 'voxel-based mesh', 'additive manufacturing'] | ADAPTIVE MESHING FRAMEWORK USING OCTREE DATA STRUCTURE FOR VOXEL BASED MESHES | Conference paper | https://repositories.lib.utexas.edu//bitstreams/a6afdf34-6629-47bf-a9d5-e68bc46a1f6b/download | University of Texas at Austin | We present an adaptive meshing framework for voxel-based meshes, designed for use in
various process simulations for additive manufacturing, such as thermal, distortion, grain growth,
etc. The framework uses an octree data structure to represent the meshes, and a
coarsening/refinement algorithm to generate coarser and finer meshes. The algorithm preserves a
2:1 ratio of coarse to fine meshes to maintain desired accuracy. Efficient tree traversal is used for
fast nodal/Gaussian solution mapping. In many cases, selective element coarsening enables the
reduction of the number of nodes to be solved by the iterative matrix solver. To maintain accuracy
at boundary, the algorithm can be configured to maintain a certain level of fine mesh at boundary.
When part and support mesh touch, they are automatically flagged to be not combined to be
coarsened at any stage. Overall, the algorithm enables reduction of solution nodes while
maintaining desired accuracy at areas of interest. | null | null | null | null | null | null |
['Xiangping, Wang', 'Haiou, Zhang', 'Guilan, Wang', 'Lingpeng, Wu'] | 2021-10-18T22:38:58Z | 2021-10-18T22:38:58Z | 2014 | Mechanical Engineering | null | https://hdl.handle.net/2152/89275 | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['Hybrid Plasma Deposition and Milling', 'adaptive slicing', 'multi-axis layered manufacturing'] | Adaptive Slicing for Multi-Axis Hybrid Plasma Deposition and Milling | Conference paper | https://repositories.lib.utexas.edu//bitstreams/8ae1bbb8-3c7f-4d0a-8ccf-54169ea147d8/download | University of Texas at Austin | Hybrid Plasma Deposition and Milling (HPDM), a five-axis manufacturing
system integrated material additive and subtractive processes, can be used to create
overhang metallic components directly without the usage of sacrificial support
structure. Different from conventional slicing methods, a new slicing algorithm with
changeable direction and thickness is proposed in this paper. Minimal overhang length
is selected as the objective function to optimize the build direction. The thickness is
adjusted to meet allowable overhang length and allowable cups height. The input
mesh is first decomposed into non-uniform thickness segment meshes and then each
segment is cut into uniform thickness slices. The output slices consist of split slices
between two adjacent segment meshes and inner slices for each segment mesh.
Examples and analyses confirm the feasibility and effectiveness. | null | null | null | null | null | null |
['Suh, Young Seok', 'Wozny, Michael J.'] | 2018-10-03T18:40:57Z | 2018-10-03T18:40:57Z | 1994 | Mechanical Engineering | doi:10.15781/T21J97T0Z | http://hdl.handle.net/2152/68677 | eng | 1994 International Solid Freeform Fabrication Symposium | Open | ['SFF', '3D aliasing', 'CAD'] | Adaptive Slicing of Solid Freeform Fabrication Processes | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b6f350a7-565a-4911-baf9-5ff682c022be/download | null | The Solid Freeform Fabrication (SFF) process significantly reduces part specific setup
manufacturing lead time. This process has been primarily used in fabricating prototypes for design
visualization and verification. However, the major impact of this process on the future of
manufacturing technology would be the possibility offabricating functional parts for end use. One
ofthe obstacles to this goal is the insufficient accuracy ofthe final physical part produced by the
process. From the software point of view, the major sources of the inaccuracy come from the
inappropriate data transfer format and the 3D aliasing' or Stair-stepping' problem.
The '3D aliasing' problem can be reduced by adapting the layer thickness to the geometry of
the part. In this paper, the procedure of adaptive slicing from the exact representation ofthe part
model is described. This will improve part accuracy and minimize building time especially for the
parts with highly curved surfaces. The procedures are implemented and a comparison to the
conventional uniform layer thickness method will be discussed. | null | null | null | null | null | null |
['Unnanon, Kittnan', 'Cormier, Denis', 'Sanii, Ezat'] | 2019-09-23T15:58:28Z | 2019-09-23T15:58:28Z | 2000 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/75947', 'http://dx.doi.org/10.26153/tsw/3046'] | eng | 2000 International Solid Freeform Fabrication Symposium | Open | Inkjet | Adaptive Slicing With the Sanders Prototype Inkjet Modeling System 259 | Conference paper | https://repositories.lib.utexas.edu//bitstreams/fb087c21-10e9-41e5-aaff-a468ef14be59/download | null | This paper presents one of the first known in depth studies of the Sanders Prototype inkjet modeling process. A process capability study was performed in order to determine the relationship between process parameter levels and the resulting surface roughness. The data was used to create a predictive model of surface roughness using a backpropagation neural network. Test results indicate that the network is quite effective at generalizing to new process configurations. The predictive surface roughness model is used in a newly developed inkjet modeling adaptive slicing algorithm. On a region-by-region basis, the algorithm determines the fastest machine configuration that can be used to build a part while satisfying the surface roughness requirements. The adaptive slicing system has been tested, and results documenting substantial time and cost savings are presented. | null | null | null | null | null | null |
['Coulson, Kevin', 'Toombs, Joseph', 'Gu, Magnus', 'Taylor, Hayden'] | 2021-12-06T23:50:41Z | 2021-12-06T23:50:41Z | 2021 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90723', 'http://dx.doi.org/10.26153/tsw/17642'] | eng | 2021 International Solid Freeform Fabrication Symposium | Open | ['adaptive voxelization', 'computed axial lithography', 'printing generation', 'compensational time'] | Adaptive Voxelization for Rapid Projection Generation in Computed Axial Lithography | Conference paper | https://repositories.lib.utexas.edu//bitstreams/7ee4836f-55c2-4eda-8376-d6b0ccb7483e/download | University of Texas at Austin | Computed axial lithography (CAL) is a tomographic additive manufacturing technology
that offers exceptionally fast printing in a wide range of materials. CAL involves pre-computing
a sequence of light patterns to be projected into a photopolymer. For a uniform spatial
discretization of the target geometry, computational time scales inversely with the cube of the
discretization pitch, which makes it challenging to exploit the full space-bandwidth product of
available spatial light modulators. This work introduces an adaptive voxelization approach to
reduce computational expense. Using one of several proposed mesh-based complexity analyses,
a CAD model is recursively subdivided into stacked sub-meshes of varying voxel resolution.
These complexity methods can be tailored to emphasize complexity in particular regions. Each
sub-mesh is then independently voxelized before projections are generated and optimized in
parallel. On a four-core CPU, this method results in a 2 − 6 × speedup with applications in high-precision CAL and other voxel-based additive manufacturing computations. | null | null | null | null | null | null |
['Shusteff, Maxim', 'Panas, Robert M.', 'Henriksson, Johannes', 'Kelly, Brett E.', 'Browar, Allison E.M.'] | 2021-10-28T15:39:37Z | 2021-10-28T15:39:37Z | 2016 | Mechanical Engineering | null | https://hdl.handle.net/2152/89665 | eng | 2016 International Solid Freeform Fabrication Symposium | Open | ['holographic lithography', 'additive manufacturing', '3D structures'] | Additive Fabrication of 3D Structures by Holographic Lithography | Conference paper | https://repositories.lib.utexas.edu//bitstreams/9bceeb91-6f5c-4e8f-b172-7015d7b86823/download | University of Texas at Austin | As additive manufacturing (AM) technologies advance and mature, the geometric
constraints imposed by fabricating 2D planar layers become increasingly important to overcome.
In the realm of light-driven AM fabrication, holography provides a promising avenue toward true
3D structures. Being capable of recording and reconstructing 3D information, holographic
shaping of the light field can enable direct 3D fabrication in photopolymer resins. We have
conceptualized, designed, and built a prototype holographic additive micromanufacturing
system, incorporating a liquid-crystal-on-silicon (LCoS) spatial light modulator (SLM) to
redirect light energy at the build volume by spatial control of the phase distribution. Here we
report the system design, design parameter trade-offs relevant for producing 3D structures, and
initial fabrication results. | null | null | null | null | null | null |
['Ramesh, S.', 'Eldakroury, M.', 'Rivero, I.V.', 'Frank, M.C.'] | 2021-11-04T20:59:48Z | 2021-11-04T20:59:48Z | 2017 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90027', 'http://dx.doi.org/10.26153/16948'] | eng | 2017 International Solid Freeform Fabrication Symposium | Open | ['bioplotting', 'chitosan', 'cryomilling', 'additive fabrication', 'bone tissue engineering'] | Additive Fabrication of Polymer-Ceramic Composite for Bone Tissue Engineering | Conference paper | https://repositories.lib.utexas.edu//bitstreams/6823bbbd-6dba-4100-8ea5-d11353d371a0/download | University of Texas at Austin | The objective of this study is to manufacture chitosan-based biocomposite 3-D scaffolds through
additive fabrication for promoting the regeneration of bone defects. Additive manufacturing has
enabled the production of effective scaffolds by overcoming traditional limitations such as
suboptimal distribution of cells, and poor control over scaffold architecture. In this study,
cryomilled biocomposites comprising of poly (lactic) acid (PLA), chitosan (CS) and tricalcium
phosphate (TCP) provided the basis for the generation of hydrogels, which were then utilized for
the fabrication of scaffolds with orthogonal (0, 90) geometry. Rheological studies were conducted
using a rotational rheometer to identify the ideal hydrogel concentration for the continuous
production of scaffolds. The scaffolds were fabricated using a 3-axis computerized numerical
control (CNC) which was modified to function as a customized bioplotter. Scanning electron
microscopy (SEM) was used to observe the morphology of the bioplotted scaffolds. Finally, a
short-term stability (14 days) study was conducted to analyze the in vitro degradation behavior of
the scaffolds in phosphate buffer saline (PBS). | null | null | null | null | null | null |
['Bandari, Yashwanth K.', 'Williams, Stewart W.', 'Ding, Jialuo', 'Martina, Filomeno'] | 2021-10-19T15:47:24Z | 2021-10-19T15:47:24Z | 2015 | Mechanical Engineering | null | https://hdl.handle.net/2152/89305 | eng | 2014 International Solid Freeform Fabrication Symposium | Open | ['additive manufacture', 'direct feed', 'robotics', 'cost'] | Additive Manufacture of Large Structures: Robotic or CNC Systems? | Conference paper | https://repositories.lib.utexas.edu//bitstreams/6cb88baa-342a-447d-b878-8f44a89f9440/download | University of Texas at Austin | Additive manufacture of metre scale parts requires direct feed processes such as blown powder or wire
feed combined with lasers or arcs. The overall system can be configured using either a robotic or Computer
Numerical Controlled (CNC) gantry system. There are many factors that determine which of these is best and
this will be presented in this paper. Some factors are inherent to the specific process type such as
accuracy/resolution and any requirement for reorientation of the feedstock and heat source. Other factors
depend on the particular application including material type, shielding options, part size/complexity, required
build strategies and management of distortion. Further considerations include the incorporation of ancillary
processes such as cold work, machining or inspection. The relative influence of these factors will be discussed.
Cost implications for the different approaches will be highlighted based upon the type of process being utilized.
Examples are provided where both robotic and CNC options have been evaluated and the best solution found. | null | null | null | null | null | null |
['Aydin, I.', 'Akarcay, E.', 'Gumus, O.F.', 'Yelek, H.', 'Engin, C.B.'] | 2021-11-30T22:13:34Z | 2021-11-30T22:13:34Z | 2019 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/90567', 'http://dx.doi.org/10.26153/tsw/17486'] | eng | 2019 International Solid Freeform Fabrication Symposium | Open | ['additive manufacturing', 'finite element analysis', 'lattice structures', 'maraging steel', 'mechanical properties', 'vehicle door hinge'] | Additive Manufactured Lightweight Vehicle Door Hinge with Hybrid Lattice Structure | Conference paper | https://repositories.lib.utexas.edu//bitstreams/f98a37b5-6776-4877-930b-6998f55c0a90/download | University of Texas at Austin | null | null | This paper presents an approach to finite element analysis of regulation to simulate mechanical behavior of door hinge with hybrid lattice structures. | null | null | null | null |
['Ivanova, Olga S.', 'Williams, Christopher B.', 'Campbell, Thomas A.'] | 2021-10-05T15:12:05Z | 2021-10-05T15:12:05Z | 2011 | Mechanical Engineering | null | ['https://hdl.handle.net/2152/88390', 'http://dx.doi.org/10.26153/tsw/15329'] | eng | 2011 International Solid Freeform Fabrication Symposium | Open | ['Additive Manufacturing', 'nanomaterials', 'nanotechnology', 'AM technologies'] | Additive Manufacturing (AM) and Nanotechnology: Promises and Challenges | Conference paper | https://repositories.lib.utexas.edu//bitstreams/b578771f-89c4-4e6a-bd1b-26e42d0cc50a/download | University of Texas at Austin | The narrow choice of materials used in Additive Manufacturing (AM) remains a key
limitation to more advanced systems. Nanomaterials offer the potential to advance AM materials
through modification of their fundamental material properties. In this paper, the authors provide
a review of available published literature in which nanostructures are incorporated into AM
printing media as an attempt to improve the properties of the final printed part. Specifically, we
review the research in which metal, ceramic, and carbon nanomaterials have been incorporated
into AM technologies such as stereolithography, laser sintering, fused filament fabrication, and
three-dimensional printing. The purpose of this article is to summarize the research done to date,
to highlight successes in the field, and to identify opportunities that the union of AM and
nanotechnology could bring to science and technology. | null | null | null | null | null | null |