On the Numerical Investigation of Material Deposition in Fused Filament Fabrication

2020 ◽  
pp. 19-36
Author(s):  
Anand Singh Yadav ◽  
Narendra Kumar ◽  
Prashant K. Jain
Keyword(s):  
Numerical Investigation ◽  
Fused Filament Fabrication ◽  
Material Deposition

scholarly journals Strength Increasing Additive Manufacturing Fused Filament Fabrication Technology, Based on Spiral Toolpath Material Deposition

Machines ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 57 ◽  
Author(s):  
Artem Avdeev ◽  
Andrey Shvets ◽  
Ilya Gushchin ◽  
Ivan Torubarov ◽  
Aleksey Drobotov ◽  
...  
Keyword(s):  
Deposition Method ◽  
Compression Tests ◽  
Fabrication Technology ◽  
Standard Samples ◽  
Fused Filament Fabrication ◽  
Material Deposition ◽  
Layer Deposition ◽  
Point Bend ◽  
Five Axis ◽  
Printing Method

The paper provides an overview of ways to increase the strength of polymer products obtained by fused filament fabrication (FFF) technology. An algorithm for calculating the spiral toolpaths for the material deposition using multi-axis printing is proposed. The design of the five-axis device for spiral-shaped deposition of the material is shown. The description of the proposed printing method is given. The results of comparative three-point bend and compression tests are presented. The standard samples obtained in the usual way by FFF technology, as well as samples with 2, 4, 6, 8 and 10 reinforcing layers obtained by spiral deposition of the material were investigated. The description of the tests is given, the dependences of the strength of the products on the number of reinforcing layers are obtained. Conclusions about the influence of the layer deposition method on the strength of the products are formulated.

scholarly journals Curvilinear Variable Stiffness 3D Printing For Improved Mechanical Performance

2021 ◽  
Author(s):  
Sadben Khan
Keyword(s):  
3D Printing ◽  
Mechanical Performance ◽  
Variable Stiffness ◽  
Fused Filament Fabrication ◽  
Work Cell ◽  
Material Deposition ◽  
Stiffness Design ◽  
Open Hole ◽  
Line Scanner ◽  
Novel Design

<div>Continuous Curvilinear Variable Stiffness (CCVS) is proposed as a novel design technique to generate Variable Stiffness design for improving the performance of composite panels featuring open-hole cut-outs. Compared to existing VS design techniques, CCVS steers the fibers around the cut-out without breaking at the holes using only a single design variable the geometry. The technique utilises a numerical method known as Source Panel method, which is typically utilised in the fluid dynamics world. Utilising this technique, the performance of an open hole ASTM D5766 coupon manufactured using Fused Filament Fabrication (FFF) was improved 16-38% depending on the ratio of the hole to the width of the specimen. The technique was further</div><div>improved on to allow for arbitrary geometries such as fuselage cut-outs. A fuselage cut-out case was examined, and it was shown that a CCVS design can improve the performance over a QuasiIsotropic design by 57%. To validate CCVS, it is necessary to first manufacture and validate the part. This was done by developing a robotic 3D printing work-cell capable of 5 axis of material deposition of both thermoplastic and pre-impregnated carbon fiber. Finally, an in-process inspection technique was developed using a laser line scanner in the work-cell for the purposes of quality control. </div>

Enhanced Toolpath Planning for Fused Filament Fabrication

2020 ◽  
Author(s):  
Hongrui Chen ◽  
Xingchen Liu
Keyword(s):  
Volume Fraction ◽  
Software Process ◽  
Manufacturing Processes ◽  
Fused Filament Fabrication ◽  
Fermat Curve ◽  
Toolpath Planning ◽  
Material Deposition ◽  
3D Geometry ◽  
Fermat Curves ◽  
Printing Time

Abstract The slicing software process the 3D geometry into 2D slices and toolpaths for additive manufacturing processes. Most slicing software allows users to select from an array of infill patterns and to specify the overall infill volume fraction globally. However, the ability to locally control the volume fraction, and mechanical properties, is often limited. In this paper, we propose a novel toolpath enhancing algorithm to enable the local control on the volume fraction of various stock and custom infill patterns. In particular, the algorithm widens the infill pattern by directly modifying their toolpath with connected Fermat curves. By preserving the topology of the original toolpath, the connected Fermat curve not only produces predictable boosts in part performance but also minimized the printing time by eliminating extruder traversals without material deposition. The field that controls local volume fraction can be designed either manually or through optimization. The effectiveness of the proposed approach in toolpath generation is demonstrated through volume fraction fields designed by both approaches.

scholarly journals Curvilinear Variable Stiffness 3D Printing For Improved Mechanical Performance

2021 ◽  
Author(s):  
Sadben Khan
Keyword(s):  
3D Printing ◽  
Mechanical Performance ◽  
Variable Stiffness ◽  
Fused Filament Fabrication ◽  
Work Cell ◽  
Material Deposition ◽  
Stiffness Design ◽  
Open Hole ◽  
Line Scanner ◽  
Novel Design

<div>Continuous Curvilinear Variable Stiffness (CCVS) is proposed as a novel design technique to generate Variable Stiffness design for improving the performance of composite panels featuring open-hole cut-outs. Compared to existing VS design techniques, CCVS steers the fibers around the cut-out without breaking at the holes using only a single design variable the geometry. The technique utilises a numerical method known as Source Panel method, which is typically utilised in the fluid dynamics world. Utilising this technique, the performance of an open hole ASTM D5766 coupon manufactured using Fused Filament Fabrication (FFF) was improved 16-38% depending on the ratio of the hole to the width of the specimen. The technique was further</div><div>improved on to allow for arbitrary geometries such as fuselage cut-outs. A fuselage cut-out case was examined, and it was shown that a CCVS design can improve the performance over a QuasiIsotropic design by 57%. To validate CCVS, it is necessary to first manufacture and validate the part. This was done by developing a robotic 3D printing work-cell capable of 5 axis of material deposition of both thermoplastic and pre-impregnated carbon fiber. Finally, an in-process inspection technique was developed using a laser line scanner in the work-cell for the purposes of quality control. </div>

Advances in Stem Instrumentation for Biology

1990 ◽  
Vol 48 (1) ◽  
pp. 362-363
Author(s):  
J. S. Wall
Keyword(s):  
Scanning Transmission Electron Microscope ◽  
Carbon Films ◽  
Specimen Preparation ◽  
Material Deposition ◽  
Active User ◽  
Percent Improvement ◽  
Scanning Transmission ◽  
The Moment ◽  
Film Substrate ◽  
High Level

The forte of the Scanning transmission Electron Microscope (STEM) is high resolution imaging with high contrast on thin specimens, as demonstrated by visualization of single heavy atoms. of equal importance for biology is the efficient utilization of all available signals, permitting low dose imaging of unstained single molecules such as DNA.Our work at Brookhaven has concentrated on: 1) design and construction of instruments optimized for a narrow range of biological applications and 2) use of such instruments in a very active user/collaborator program. Therefore our program is highly interactive with a strong emphasis on producing results which are interpretable with a high level of confidence.The major challenge we face at the moment is specimen preparation. The resolution of the STEM is better than 2.5 A, but measurements of resolution vs. dose level off at a resolution of 20 A at a dose of 10 el/A2 on a well-behaved biological specimen such as TMV (tobacco mosaic virus). To track down this problem we are examining all aspects of specimen preparation: purification of biological material, deposition on the thin film substrate, washing, fast freezing and freeze drying. As we attempt to improve our equipment/technique, we use image analysis of TMV internal controls included in all STEM samples as a monitor sensitive enough to detect even a few percent improvement. For delicate specimens, carbon films can be very harsh-leading to disruption of the sample. Therefore we are developing conducting polymer films as alternative substrates, as described elsewhere in these Proceedings. For specimen preparation studies, we have identified (from our user/collaborator program ) a variety of “canary” specimens, each uniquely sensitive to one particular aspect of sample preparation, so we can attempt to separate the variables involved.

Evaluation of a Modified Fused Filament Fabrication Material for Use As Thermal Protection

2019 ◽  
Author(s):  
Steven Kim ◽  
Alexa Devega ◽  
Mallory Sico ◽  
Hao Wu ◽  
William Fahy ◽  
...  
Keyword(s):  
Thermal Protection ◽  
Fused Filament Fabrication
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