A Conceptual Design and Modeling Framework for Integrated Additive Manufacturing

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Hossein Mokhtarian ◽  
Eric Coatanéa ◽  
Henri Paris ◽  
Mouhamadou Mansour Mbow ◽  
Franck Pourroy ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Process Model ◽  
Conceptual Modeling ◽  
Three Dimensional ◽  
Integrated Model ◽  
Performance Model ◽  
Process Equipment ◽  
3D Printer ◽  
Fused Filament Fabrication ◽  
Modeling Framework

Modeling and simulation for additive manufacturing (AM) is commonly used in industry. Nevertheless, a central issue remaining is the integration of different models focusing on different objectives and targeting different levels of details. The objective of this work is to increase the prediction capability of characteristics and performances of additively manufactured parts and to co-design parts and processes. The paper contributes to this field of research by integrating part's performance model and additive technology process model into a single early integrated model. The paper uses the dimensional analysis conceptual modeling (DACM) framework in an AM perspective to generate causal graphs integrating the AM equipment and the part to be printed. DACM offers the possibility of integrating existing knowledge in the model. The framework supported by a computer tool produces a set of governing equations representing the relationships among the influencing variables of the integrated model. The systematic identification of the weaknesses and contradictions in the system and qualitative simulation of the system are some of the potential uses of the model. Ultimately, it is a way to create better designs of machines and parts, to control and qualify the manufacturing process, and to control three-dimensional (3D) printing processes. The DACM framework is tested on two cases of a 3D printer using the fused filament fabrication (FFF) powder bed fusion. The analysis, applied to the global system formed of the 3D printer and the part, illustrates the existence of contradictions. The analysis supports the early redesign of both parts and AM process (equipment) and later optimization of the control parameters.

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.

Design of Three-Dimensional, Triply Periodic Unit Cell Scaffold Structures for Additive Manufacturing

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Mazher Iqbal Mohammed ◽  
Ian Gibson
Keyword(s):  
Additive Manufacturing ◽  
Periodic Structures ◽  
Three Dimensional ◽  
Unit Cell ◽  
Final Size ◽  
Fused Filament Fabrication ◽  
Cell Structures ◽  
Triply Periodic ◽  
Unit Cells ◽  
Scaffold Structure

Highly organized, porous architectures leverage the true potential of additive manufacturing (AM) as they can simply not be manufactured by any other means. However, their mainstream usage is being hindered by the traditional methodologies of design which are heavily mathematically orientated and do not allow ease of controlling geometrical attributes. In this study, we aim to address these limitations through a more design-driven approach and demonstrate how complex mathematical surfaces, such as triply periodic structures, can be used to generate unit cells and be applied to design scaffold structures in both regular and irregular volumes in addition to hybrid formats. We examine the conversion of several triply periodic mathematical surfaces into unit cell structures and use these to design scaffolds, which are subsequently manufactured using fused filament fabrication (FFF) additive manufacturing. We present techniques to convert these functions from a two-dimensional surface to three-dimensional (3D) unit cell, fine tune the porosity and surface area, and examine the nuances behind conversion into a scaffold structure suitable for 3D printing. It was found that there are constraints in the final size of unit cell that can be suitably translated through a wider structure while still allowing for repeatable printing, which ultimately restricts the attainable porosities and smallest printed feature size. We found this limit to be approximately three times the stated precision of the 3D printer used this study. Ultimately, this work provides guidance to designers/engineers creating porous structures, and findings could be useful in applications such as tissue engineering and product light-weighting.

scholarly journals A 3D weaving infill pattern for fused filament fabrication

2021 ◽  
Author(s):  
Yuan Yao ◽  
Cheng Ding ◽  
Mohamed Aburaia ◽  
Maximilian Lackner ◽  
Lanlan He
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Repetitive Structure ◽  
Mechanical Linkage ◽  
Manufacturing Technologies ◽  
Dimensional Object ◽  
Anisotropy Of Mechanical Properties ◽  
3D Weaving

Abstract The Fused Filament Fabrication process is the most used additive manufacturing process due to its simplicity and low operating costs. In this process, a thermoplastic filament is led through an extruder, melted, and applied to a building platform by the axial movements of an automated Cartesian system in such a way that a three-dimensional object is created layer by layer. Compared to other additive manufacturing technologies, the components produced have mechanical limitations and are often not suitable for functional applications. To reduce the anisotropy of mechanical strength in fused filament fabrication (FFF), this paper proposes a 3D weaving deposit path planning method that utilizes a 5-layer repetitive structure to achieve interlocking and embedding between neighbor slicing planes to improve the mechanical linkage within the layers. The developed algorithm extends the weaving path as an infill pattern to fill different structures and makes this process feasible on a standard three-axis 3D printer. Compared with 3D weaving printed parts by layer-to-layer deposit, the anisotropy of mechanical properties inside layers is significantly reduced to 10.21% and 0.98%.

scholarly journals Sustainable Additive Manufacturing: Mechanical Response of Polyethylene Terephthalate Glycol over Multiple Recycling Processes

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1162
Author(s):  
Nectarios Vidakis ◽  
Markos Petousis ◽  
Lazaros Tzounis ◽  
Sotirios A. Grammatikos ◽  
Emmanouil Porfyrakis ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Polyethylene Terephthalate ◽  
Mechanical Response ◽  
Three Dimensional ◽  
Thermal Response ◽  
Fused Filament Fabrication ◽  
Hardness Tests ◽  
Multiple Recycling ◽  
A Minor

The continuous demand for thermoplastic polymers in a great variety of applications, combined with an urgent need to minimize the quantity of waste for a balanced energy-from-waste strategy, has led to increasing scientific interest in developing new recycling processes for plastic products. Glycol-modified polyethylene terephthalate (PETG) is known to have some enhanced properties as compared to polyethylene terephthalate (PET) homopolymer; this has recently attracted the interest from the fused filament fabrication (FFF) three-dimensional (3D) printing community. PET has shown a reduced ability for repeated recycling through traditional processes. Herein, we demonstrate the potential for using recycled PETG in consecutive 3D printing manufacturing processes. Distributed recycling additive manufacturing (DRAM)-oriented equipment was chosen in order to test the mechanical and thermal response of PETG material in continuous recycling processes. Tensile, flexure, impact strength, and Vickers micro-hardness tests were carried out for six (6) cycles of recycling. Finally, Raman spectroscopy as well as thermal and morphological analyses via scanning electron microscopy (SEM) fractography were carried out. In general, the results revealed a minor knockdown effect on the mechanical properties as well as the thermal properties of PETG following the process proposed herein, even after six rounds of recycling.

scholarly journals Design and Development of Plastic Filament Extruder for 3D Printing

2018 ◽  
Vol 10 (3) ◽  
pp. 23 ◽  
Author(s):  
Mamta H. Wankhade ◽  
Satish G. Bahaley
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Three Dimensional ◽  
3D Printer ◽  
3D Objects ◽  
Fused Deposition ◽  
Additive Manufacturing Technology ◽  
Mechanized Method ◽  
Dimensional Object ◽  
The Cost

<p>3D printing is a form of additive manufacturing technology where a three dimensional object is created by laying down successive layers of material. It is mechanized method whereby 3D objects are quickly made on a reasonably sized machine connected to a computer containing blueprints for the object. As 3D printing is growing fast and giving a boost to product development, the factories doing 3D printing need to continuously meet the printing requirements and maintain an adequate amount of inventory of the filament. As the manufactures have to buy these filaments from various vendors, the cost of 3D printing increases. To overcome the problem faced by the manufacturers, small workshop owners, the need of 3D filament making machine arises. This project focuses on designing and fabricating a portable fused deposition 3D printer filament making machine with cheap and easily available components to draw 1.75 mm diameter ABS filament.</p>

scholarly journals 3D PRINTER DESIGN, MANUFACTURING AND EFFECT OF INFILL PATTERNS ON MECHANICAL PROPERTlES

2020 ◽  
Vol 4 (1) ◽  
pp. 13-24
Author(s):  
Hande Güler Özgül ◽  
Onur Tatlı
Keyword(s):  
Additive Manufacturing ◽  
Fused Deposition Modeling ◽  
Tensile Force ◽  
Three Dimensional ◽  
Charpy Impact ◽  
3D Printer ◽  
Direct Production ◽  
Fused Deposition ◽  
Technological Developments ◽  
Manufacturing Technologies

Along with the technological developments, it is an expected situation to discover new developed production methods. Additive manufacturing technologies, such as three-dimensional (3D) printers are one of these methods, allowing direct production of parts with complex geometries that cannot be produced by conventional methods. The most popular and inexpensive method among additive manufacturing technologies is FDM (Fused Deposition Modeling) method. This method is particularly interesting for the manufacture of parts with low production volumes. In this study, a 3D-FDM printer with a print volume of 200x200x210 mm has been designed and manufactured.PLA (polylactic acid) test samples having 2 different infill geometries were produced with the 3D printer. Tensile, three-point bending and charpyimpact tests were applied to these samples to investigate the effect of inner filling geometry on mechanical properties. The inner filling geometries are in the form of grid and gyroid. According to the results, while the geometry with the tensile force is "grid", while the geometry with the maximum bending force is "gyroid".It was concluded that different inner filling geometries do not have a significant impact on Charpy impact strength.

Validation of design and materials for additive manufacturing of endocavitary mechanical distractor

2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jose Manuel Sierra ◽  
Maria del Rocio Fernandez ◽  
Jose Ignacio Ignacio Rodriguez Garcia ◽  
Jose Luis Cortizo ◽  
Marta María Villazon
Keyword(s):  
Additive Manufacturing ◽  
Low Income ◽  
High Performance ◽  
Design Methodology ◽  
Three Dimensional ◽  
3D Printer ◽  
Validation Process ◽  
Content Type ◽  
Endoscopic Microsurgery ◽  
Optimal Material

Purpose This paper describes the evolution of the design of a mechanical distractor fabricated using additive manufacturing (AM) technology for use in surgical procedures, such as transanal endoscopic microsurgery (TEM). The functionality of the final device was analysed and the suitability of different materials was determined. Design/methodology/approach Solid modelling and finite element modelling software were used in the design and validation process to allow the fabrication of the device by AM. Several prototypes were manufactured and tested in this study. Findings A new design was developed to greatly simplify the existing devices used in TEM surgery. The new design is easy to use, more economical and does not require pneumorectum. Different AM materials were investigated with regard to their mechanical properties, orientation of parts in the three-dimensional (3D) printer and cytotoxicity to select the optimal material for the design. Social implications The device designed by AM can be printed anywhere in the world, provided that a 3D printer is available; the 3D printer does not have to be a high-performance printer. This makes surgery more accessible, particularly in low-income regions. Moreover, patient recovery is improved and pneumorectum is not required. Originality/value A suitable mechanical distractor was designed for TEM, and different materials were validated for fabrication by AM.

Review on process model, structure-property relationship of composites and future needs in fused filament fabrication

2020 ◽  
Vol 39 (19-20) ◽  
pp. 758-789 ◽  
Author(s):  
Easir Arafat Papon ◽  
Anwarul Haque
Keyword(s):  
Additive Manufacturing ◽  
Computational Modeling ◽  
Process Modeling ◽  
Process Model ◽  
Nozzle Geometry ◽  
Future Research ◽  
Void Content ◽  
Fused Filament Fabrication ◽  
General Overview ◽  
Macro Scale

This paper presents the state-of-the-art of additive manufacturing of composites for processing functional, load-bearing components. A general overview of different additive manufacturing methods is provided, and specific attention is focused on fused filament fabrication-based composites processing. Different process modeling strategies are summarized, and key aspects of these models are discussed. Significant results such as thermal and fluid flow characteristics, effects of nozzle geometry on melt flow, fiber orientation, bead spreading, and solidification, the formation of residual stresses, and deformation behavior are discussed from computational modeling perspective. The scientific advancement, model limitations, and future modeling needs are prescribed reviewing the current works. A general overview of material development in nano-micro-macro-scale reinforcement is also presented. Different length-scales of reinforcement has its own challenges and promises. The continuous fiber reinforcement has a great potential for being the next-generation composites manufacturing technology. However, the challenges in reducing the void content, better bonding between the fiber–matrix, and layer-layer adhesion, and process uncertainty are some of the key areas yet to advance. Based on the current limitations on computational modeling, materials development, and process modeling studies, future research needs and recommendations are provided.

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