Effect of Metallic Fibers on the Print Quality and Strength of 3D Printed Concrete

Abstract The purpose of this project is to design a device that improves the performance of a ceramic additive manufacturing (AM) 3D printer constructed by Army Research Labs (ARL). ARL modified a standard LulzBot Taz 6 3D printer to print a ceramic slurry mixture of Boron Carbide (B4C) and Silicon Carbide (SiC) instead of plastic filament. Since these compounds are often used in body armor, ARL has been observing the effects on properties when these components are 3D printed. The current printer utilizes an auger in the print head to receive and mix the B4C and SiC slurries and extrude the combined slurry out of the print nozzle. The current design is limited in its ability to thoroughly mix the slurries during the printing process. Therefore, team Concept Creators has designed an improved auger that will increase the mixedness of the slurries, thus increasing the print quality of the composite specimen.

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On the reinforcement of cement mortars through 3D printed polymeric and metallic fibers

Composites Part B Engineering ◽

10.1016/j.compositesb.2015.12.006 ◽

2016 ◽

Vol 90 ◽

pp. 76-85 ◽

Cited By ~ 71

Author(s):

I. Farina ◽

F. Fabbrocino ◽

G. Carpentieri ◽

M. Modano ◽

A. Amendola ◽

...

Keyword(s):

Cement Mortars ◽

3D Printed ◽

Metallic Fibers

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Optimization of 3d-Printer Enclosure Environment

10.21203/rs.3.rs-555977/v1 ◽

2021 ◽

Author(s):

Thomas J. May ◽

Babak Eslami ◽

Kamran Fouladi

Keyword(s):

Ultimate Strength ◽

Experimental Testing ◽

Elastic Behavior ◽

Print Quality ◽

3D Printer ◽

3 Dimensional ◽

3D Printed ◽

Computational Fluid Dynamics Cfd

Abstract Additive manufacturing has become a widely utilized process in industrial, academic, and household applications. Previous studies have demonstrated that non-optimum humidity conditions can adversely impact the print quality of parts printed from plastic filaments by changing their mechanical properties, such as elastic modulus and ultimate strength. This study utilized a computational fluid dynamics (CFD) approach and experimental testing to design a system that yields a more uniform humidity distribution in a 3-dimensional (3D) printer printing region. The study resulted in an optimized enclosure with significantly higher relative humidity (RH) uniformity in the print volume. The simulations predicted that the optimized enclosure would improve the uniformity by about 65%, while experimental testing pointed to even more significant improvement at about 75%. As a case study, tensile testing of 3D printed specimens made from NinjaFlex© filamenets under the optimum environmental conditions showed 11% higher ultimate strength and more elastic behavior than specimens printed using the baseline model.

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Fused Deposition Modeling With Added Vibrations: A Parametric Study on the Accuracy of Printed Parts

Volume 2A: Advanced Manufacturing ◽

10.1115/imece2019-11698 ◽

2019 ◽

Cited By ~ 1

Author(s):

Joseph Dei Rossi ◽

Ozgur Keles ◽

Vimal Viswanathan

Keyword(s):

Engineering Students ◽

Fused Deposition Modeling ◽

Maximum Amplitude ◽

Disruptive Technology ◽

Print Quality ◽

Optimum Level ◽

Fused Deposition ◽

3D Printers ◽

3D Printed

Abstract Additive manufacturing is a potentially disruptive technology with a rapidly growing market. The recent development of RepRap style 3D printers has made this technology available to the public at a low cost. While these 3D printers are being used for a variety of purposes, many mechanical engineering students use them for prototyping in their projects. The quality of the 3D printed parts has been a concern in such cases. There are many variables within the operation of these printers that can be varied to obtain optimum print quality. This study explores the use of externally induced mechanical vibrations to the nozzle tip as a potential method to improve the quality of 3D printed parts. Induced vibration is expected to decrease the porosity of printed parts and improve the cohesion between print beads, ultimately improving their mechanical properties. The objective is to understand the positional accuracy of the prints with the added vibration and then to determine the optimum level of vibration to achieve best quality prints. For the study, the extruder filament is replaced with a pointed-tip pen that can mark the exact location where the printer delivers the material. A comparison between the locations marked by the pen with and without vibrations shows that the errors induced by the added vibration are not significantly different from those caused by the uncertainties of the printer itself. Further, this study also explores the optimum motor speeds to achieve a uniform distribution of material and determines medium motor speeds that provide maximum amplitude of vibration which are more desirable for a uniform infill.

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Basic fresh-state properties of extrusion-based 3D printed concrete

Gradjevinski materijali i konstrukcije ◽

10.5937/grmk2004099b ◽

2020 ◽

Vol 63 (4) ◽

pp. 99-117

Author(s):

Olivera Bukvić ◽

Vlastimir Radonjanin ◽

Mirjana Malešev ◽

Mirjana Laban

Keyword(s):

Recent Literature ◽

Three Dimensional ◽

Print Quality ◽

Construction Technology ◽

Inclusion Criteria ◽

Starting Point ◽

Fresh State ◽

3D Printed ◽

Hardened Properties ◽

Materials Used

This paper aims at reviewing the basic properties of fresh-state extrusion-based three-dimensional (3D) printed concrete in order to explain the specific properties of this construction technology. The review was conducted using the bottom-up approach. The most recent literature in the field of extrusion-based concrete printing was used as a starting point, while additional papers were included through screening the references of relevant papers. Based on the inclusion criteria, review and experimental papers containing data on fresh-state 3D printed concrete properties were included, as well as materials used for 3D printing, since their properties directly affect the fresh-state properties of concrete mixture. Papers concerning data only on hardened properties were excluded. Reviewed properties are: technological properties (pump ability and flow ability) and printability properties(extrudability, print quality and buildability).

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Comparison of Properties of 3D-Printed Mortar in Air vs. Underwater

Materials ◽

10.3390/ma14195888 ◽

2021 ◽

Vol 14 (19) ◽

pp. 5888

Author(s):

Seong-Jin Woo ◽

Jun-Mo Yang ◽

Hojae Lee ◽

Hong-Kyu Kwon

Keyword(s):

3D Printing ◽

Deposition Time ◽

Time Interval ◽

Print Quality ◽

Moisture Evaporation ◽

Fresh State ◽

Hardened State ◽

3D Printed ◽

Positive Effect ◽

Interlayer Bond

Research and technological advancements in 3D concrete printing (3DCP) have led to the idea of applying it to offshore construction. The effect of gravity is reduced underwater, which can have a positive effect on 3DCP. For basic verification of this idea, this study printed and additively manufactured specimens with the same mortar mixture in air and underwater and evaluated properties in the fresh state and the hardened state. The mechanical properties were evaluated using the specimens produced by direct casting to the mold and specimens produced by extracting from the additive part through coring and cutting. The results of the experiment show that underwater 3D printing required a greater amount of printing output than in-air 3D printing for a good print quality, and buildability was improved underwater compared to that in air. In the case of the specimen layered underwater, the density and compressive strength decreased compared to the specimen layered in air. Because there are almost no effects of moisture evaporation and bleeding in water, the interlayer bond strength of the specimen printed underwater was somewhat larger than that printed in air, while there was no effect of the deposition time interval underwater.

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