Overhanging Feature Analysis for the Additive Manufacturing of Topology Optimized Structures

2018 ◽  
Author(s):  
Dylan Bender ◽  
Ahmad Barari
Keyword(s):  
Additive Manufacturing ◽  
Difference Operator ◽  
Optimized Design ◽  
3D Printer ◽  
Structural Topology ◽  
Gradient Vector ◽  
Distribution Matrix ◽  
Structural Parts ◽  
Part Orientation

This paper presents a methodology to find the optimum build orientation in the additive manufacturing of topologically optimized structural parts. The outlined methodology is based on applying a differential operator to the density distribution matrix of a topologically optimized design. The methodology is developed for 2D parts, where the profile of the geometry is constant. The 2D spatial difference operator effectively calculates the elemental density gradient vector, ultimately used to calculate the angles between i) overhanging surfaces of a topology optimized design, and ii) the build platform of a 3D printer. These angles, referred to as build angles, are used to estimate the relative amount of supporting structure required to print the design at a prescribed part orientation. This methodology can potentially be adopted to simulate the additive manufacturing surface quality of density based, structural topology optimization designs.

scholarly journals The Influence of Different Slicer Software on 3d Printing Products Accuracy and Surface Roughness

2021 ◽  
Vol 12 (2) ◽  
pp. 371-380
Author(s):  
Sally Cahyati ◽  
◽  
Haris Risqy Aziz
Keyword(s):  
Surface Roughness ◽  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
High Surface ◽  
3D Printer ◽  
Layer By Layer ◽  
Additive Manufacturing Technology ◽  
Printing Machine

Rapid Prototyping (RP) is a manufacturing process that produces a 3D model CAD to be a real product rapidly by using additive manufacturing technology. In this case, the product will print layer by layer uses a 3D printer machine. The 3D printer requires slicer software to convert CAD data into data that a 3D printer machine can read. Research is done to analyze the effect of three kinds of slicer software on 3D printing objects on the accuracy and surface roughness of the product. The 3D model CAD is sliced using three different slicer software, namely Ideamaker, Repetier Host, and Cura. The slice model result from each slicer will be printed on a 3D printer machine with the same process parameters to be compared. Then the product's dimensional and surface roughness will be measured to determine the effect of each slicer on product quality. The best quality of the product reflected the most suitable slicer software for the 3D printing machine that used. The best results achieved by Cura slicer because it has resulted in small dimensional deviations (max 0,0308±0,0079) and stabile high surface roughness of the product (max 1,585+059).

Additive Manufacturing With Ceramics

2020 ◽  
Author(s):  
Kjetil Cline ◽  
Andrew LaFlam ◽  
Logan Smith ◽  
Margaret Nowicki ◽  
Nicholas Ku
Keyword(s):  
Additive Manufacturing ◽  
Body Armor ◽  
Print Quality ◽  
3D Printer ◽  
Current Design ◽  
3D Printed ◽  
To Receive ◽  
Boron Carbide B4c ◽  
Team Concept

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.

scholarly journals The advantages of combining 3D printing with turning process. Case study

2021 ◽  
Vol 343 ◽  
pp. 02010
Author(s):  
Dan Claudiu Negrău ◽  
Gavril Grebenisan ◽  
Ion Cosmin Gherghea ◽  
Daniel Anton
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Lead Time ◽  
Dimensional Accuracy ◽  
3D Printer ◽  
Technological Properties ◽  
Turning Process ◽  
Finishing Process

The paper presents a case study which the additive manufacturing technology is combined with finishing process by cutting operations (turning) for manufacturing a part. The part was manufactured through additive manufacturing, using a 3D printer and the and the finishing process is performed by a lathe, resulting in technological properties and the corresponding dimensional accuracy. The research paper also contains the analysis of the roughness and other properties of the material from which the final part will be made. The manufactured part will be used as a support for the blades of a fan during the assembly process, which emphasizes that a part obtained by additive manufacturing (3D printing) can replace a part obtained by casting or fabrication by total cutting. In conclusion, obtaining the manufactured part by combining the two manufacturing processes, the lead time and the production cost has been significantly reduced, while the quality of the obtained product also increased, obtaining a very good roughness.

scholarly journals Efficient 3D printing via photooxidation of ketocoumarin based photopolymerization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xiaoyu Zhao ◽  
Ye Zhao ◽  
Ming-De Li ◽  
Zhong’an Li ◽  
Haiyan Peng ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Visible Light ◽  
Light Exposure ◽  
Three Dimensional ◽  
3D Printer ◽  
Light Penetration ◽  
Viable Solution

AbstractPhotopolymerization-based three-dimensional (3D) printing can enable customized manufacturing that is difficult to achieve through other traditional means. Nevertheless, it remains challenging to achieve efficient 3D printing due to the compromise between print speed and resolution. Herein, we report an efficient 3D printing approach based on the photooxidation of ketocoumarin that functions as the photosensitizer during photopolymerization, which can simultaneously deliver high print speed (5.1 cm h−1) and high print resolution (23 μm) on a common 3D printer. Mechanistically, the initiating radical and deethylated ketocoumarin are both generated upon visible light exposure, with the former giving rise to rapid photopolymerization and high print speed while the latter ensuring high print resolution by confining the light penetration. By comparison, the printed feature is hard to identify when the ketocoumarin encounters photoreduction due to the increased lateral photopolymerization. The proposed approach here provides a viable solution towards efficient additive manufacturing by controlling the photoreaction of photosensitizers during photopolymerization.

scholarly journals Deterministic part orientation in additive manufacturing using feature recognition

Procedia CIRP ◽  
2020 ◽  
Vol 88 ◽  
pp. 405-410
Author(s):  
Torbjørn Schjelderup Leirmo ◽  
Kristian Martinsen
Keyword(s):  
Additive Manufacturing ◽  
Feature Recognition ◽  
Part Orientation

scholarly journals Automated Testing and Characterization of Additive Manufacturing (ATCAM)

2021 ◽  
Author(s):  
Arash Alex Mazhari ◽  
Randall Ticknor ◽  
Sean Swei ◽  
Stanley Krzesniak ◽  
Mircea Teodorescu
Keyword(s):  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Cell System ◽  
Automated Testing ◽  
Fused Deposition ◽  
Deposition Modeling ◽  
Machine Calibration

AbstractThe sensitivity of additive manufacturing (AM) to the variability of feedstock quality, machine calibration, and accuracy drives the need for frequent characterization of fabricated objects for a robust material process. The constant testing is fiscally and logistically intensive, often requiring coupons that are manufactured and tested in independent facilities. As a step toward integrating testing and characterization into the AM process while reducing cost, we propose the automated testing and characterization of AM (ATCAM). ATCAM is configured for fused deposition modeling (FDM) and introduces the concept of dynamic coupons to generate large quantities of basic AM samples. An in situ actuator is printed on the build surface to deploy coupons through impact, which is sensed by a load cell system utilizing machine learning (ML) to correlate AM data. We test ATCAM’s ability to distinguish the quality of three PLA feedstock at differing price points by generating and comparing 3000 dynamic coupons in 10 repetitions of 100 coupon cycles per material. ATCAM correlated the quality of each feedstock and visualized fatigue of in situ actuators over each testing cycle. Three ML algorithms were then compared, with Gradient Boost regression demonstrating a 71% correlation of dynamic coupons to their parent feedstock and provided confidence for the quality of AM data ATCAM generates.

Elasto-Plastic Stress Distribution in Triplate Joint Assembly under Bending Moment

2007 ◽  
Vol 345-346 ◽  
pp. 1437-1440
Author(s):  
Tae Hyun Baek ◽  
Seung Kee Koh ◽  
Jie Cheng
Keyword(s):  
Finite Element Method ◽  
Residual Stresses ◽  
Pure Aluminum ◽  
Main Tool ◽  
Bending Moment ◽  
The Finite Element Method ◽  
Shipbuilding Industry ◽  
Structural Parts ◽  
Von Mises

Pre-produced triplate transition joint assemblies are widely used in shipbuilding industry to make welds between aluminum and steel for a number of years now. The straight-shaped transition joint assemblies are bent during shipbuilding. So it is necessary to study the residual stresses created by punch forming, which would have heavy effects on the quality of structural parts. ABAQUS is a suite of powerful engineering simulation programs, based on the finite element method. In this paper, ABAQUS was used as the main tool to simulate the residual stresses in a triplate transition joint after unloading. Punch-pressing was carried to simulate bending moment in ABAQUS. The triplate is consisted of baselayer (steel: Lloyd’s Shipplate Gr. A), interlayer (pure aluminum: Al99.5) and superlayer (Al-Mg alloy: AlMg4.5Mn). Results from the ABAQUS analysis showed that increasing the radius of punch significantly reduced the von Mises residual stresses in steel. Changes of von Mises residual stresses in interlayer (Al99.5) and superlayer (AlMg4.5Mn) were negligible.

Investigation and Characterization of Clay Mixture Feedstock for Extrusion-Based Additive Manufacturing

2020 ◽  
Author(s):  
Tawaddod Alkindi ◽  
Mozah Alyammahi ◽  
Rahmat Agung Susantyoko
Keyword(s):  
Cost Efficiency ◽  
Ceramic Materials ◽  
3D Printer ◽  
Mixing Processes ◽  
Ceramic Components ◽  
Computer Controlled ◽  
Continuous Material ◽  
Printing Speed

Abstract The extrusion-based AM technique has been recently employed for rapid ceramic components fabrication due to scalability and cost-efficiency. This paper investigated aspects of the extrusion technique to print ceramic materials. Specifically, we assessed and developed a process recipe of the formulations (the composition of water and ethanol-based clay mixtures) and mixing processes. Different clay paste formulations were prepared by varying clay, water, ethanol ratios. The viscosity of clay paste was measured using a DV3T Viscometer. Afterward, the produced clay paste was used as a feedstock for WASP Delta 60100 3D printer for computer-controlled extrusion deposition. We evaluated the quality of the clay paste based on (i) pumpability, (ii) printability, and (iii) buildability. Pressure and flow rate were monitored to assess the pumpability. The nozzle was monitored for continuous material extrusion to assess printability. The maximum layer-without-collapse height was monitored to assess the buildability. This study correlated the mixture composition and process parameters, to the viscosity of the mixture, at the same printing speed. We found that 85 wt% clay, 5 wt% water, 10 wt% ethanol paste formulation, with the viscosity of 828000 cP, 202400 cP, 40400 cP at 1, 5, and 50 rpm, respectively, demonstrates good pumpability, as well as best printability and buildability.

Innovative Design, Structural Optimization and Additive Manufacturing of New-Generation Turbine Blades

2021 ◽  
pp. 1-31
Author(s):  
Lorenzo Pinelli ◽  
Andrea Amedei ◽  
Enrico Meli ◽  
Federico Vanti ◽  
Benedetta Romani ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Structural Optimization ◽  
Turbine Blade ◽  
Turbine Blades ◽  
Topological Optimization ◽  
Mode Shapes ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
New Generation

Abstract The need for high performances is pushing the complexity of mechanical design at very high levels, especially for turbomachinery components. Structural topology optimization methods together with additive manufacturing techniques for high resistant alloys are considered very promising tools, but their potentialities have not been deeply investigated yet for critical rotating components like new-generation turbine blades. This research work proposes a methodology for the design, the optimization and the additive manufacturing of extremely stressed turbomachinery components like turbine blade-rows. The presented procedure pays particular attention to important aspects of the problems as fluid-structure interactions and fatigue of materials, going beyond the standard structural optimization approaches found in the literature. The numerical procedure shows robustness and efficiency, making the proposed methodology a good tool for rapid design and prototyping, and for reducing the design costs and the time-to-market typical of these mechanical elements. The procedure has been applied to a low-pressure turbine rotor to improve the aeromechanical behavior while keeping the aerodynamic performance. From the original geometry, mode-shapes, forcing functions and aerodynamic damping have been numerically evaluated and are used as input data for the following topological optimization. Finally, the optimized geometry has been verified in order to confirm the improved aeromechanical design. After the structural topology optimization, the final geometries provided by the procedure have been then properly rendered to make them suitable for additive manufacturing. Some prototypes of the new optimized turbine blade have been manufactured to be tested in terms of fatigue.

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