scholarly journals A Layer-Arranged Meshless Method for the Simulation of Additive Manufacturing with Irregular Shapes

Micromachines ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 674
Author(s):  
Ming-Hsiao Lee ◽  
Wen-Hwa Chen ◽  
Ying Mao
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Meshless Method ◽  
Element Distribution ◽  
Layer By Layer ◽  
Analysis Model ◽  
Printing Process ◽  
Manufacturing Method ◽  
Geometry Model ◽  
Analysis Scheme

Additive manufacturing (3D Printing) has become a promising manufacturing method as it can produce parts in a flexible and efficient way, especially for very irregular parts. However, during the printing process, the material experiences a great temperature change from the melting temperature to room temperature; this causes high thermal strains and induces distinct deformations which degrade the quality of the printed parts, especially in metal 3D printing. In order to reduce possible problems and find possible solutions, a prior evaluation by simulation is often adopted. Nevertheless, since the 3D printing process generates parts in a layer-by-layer way, the analysis model should also be layer-by-layer arranged and used with a layer-by-layer based analysis process to simulate the layer-by-layer additive printing; otherwise, the simulation may not match the real behavior. In order to meet these requirements, a new meshless method is proposed to match the situations and handle these problems. As a meshless method, the modeling is not constrained by the element distribution. In addition, the analysis model generated with the proposed method can be arranged in a layer-by-layer way and combined with the proposed layer-by-layer analysis scheme, so it can then match and simulate the printing processes. Furthermore, the layer-by-layer arranged models can be automatically created, directly based on the STL (STereo-Lithography) geometry model, which is a de facto standard in the 3D printing industry. This makes the proposed approach more straightforward and efficient. To validate the proposed method, two parts with holes inside have been printed and simulated for comparison. The results show a good agreement. In addition, a highly irregular part has also been simulated to demonstrate the effectiveness and efficiency of this proposed method.

A review of additive manufacturing applications in ophthalmology

2021 ◽  
pp. 095441192110280
Author(s):  
Arivazhagan Pugalendhi ◽  
Rajesh Ranganathan
Keyword(s):  
Additive Manufacturing ◽  
Treatment Planning ◽  
Physical Object ◽  
Layer By Layer ◽  
Case Examples ◽  
Manufacturing Method ◽  
3D Cad ◽  
Stl File ◽  
Potential Applications ◽  
Manufacturing Applications

Additive Manufacturing (AM) capabilities in terms of product customization, manufacture of complex shape, minimal time, and low volume production those are very well suited for medical implants and biological models. AM technology permits the fabrication of physical object based on the 3D CAD model through layer by layer manufacturing method. AM use Magnetic Resonance Image (MRI), Computed Tomography (CT), and 3D scanning images and these data are converted into surface tessellation language (STL) file for fabrication. The applications of AM in ophthalmology includes diagnosis and treatment planning, customized prosthesis, implants, surgical practice/simulation, pre-operative surgical planning, fabrication of assistive tools, surgical tools, and instruments. In this article, development of AM technology in ophthalmology and its potential applications is reviewed. The aim of this study is nurturing an awareness of the engineers and ophthalmologists to enhance the ophthalmic devices and instruments. Here some of the 3D printed case examples of functional prototype and concept prototypes are carried out to understand the capabilities of this technology. This research paper explores the possibility of AM technology that can be successfully executed in the ophthalmology field for developing innovative products. This novel technique is used toward improving the quality of treatment and surgical skills by customization and pre-operative treatment planning which are more promising factors.

scholarly journals A Review on Development of Bio-Inspired Implants Using 3D Printing

Biomimetics ◽  
2021 ◽  
Vol 6 (4) ◽  
pp. 65
Author(s):  
Ansheed A. Raheem ◽  
Pearlin Hameed ◽  
Ruban Whenish ◽  
Renold S. Elsen ◽  
Aswin G ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Layer By Layer ◽  
Medical Implants ◽  
3D Print ◽  
Metal Implants ◽  
Natural Tissue ◽  
And Control ◽  
Natural Architecture ◽  
Fine Tune

Biomimetics is an emerging field of science that adapts the working principles from nature to fine-tune the engineering design aspects to mimic biological structure and functions. The application mainly focuses on the development of medical implants for hard and soft tissue replacements. Additive manufacturing or 3D printing is an established processing norm with a superior resolution and control over process parameters than conventional methods and has allowed the incessant amalgamation of biomimetics into material manufacturing, thereby improving the adaptation of biomaterials and implants into the human body. The conventional manufacturing practices had design restrictions that prevented mimicking the natural architecture of human tissues into material manufacturing. However, with additive manufacturing, the material construction happens layer-by-layer over multiple axes simultaneously, thus enabling finer control over material placement, thereby overcoming the design challenge that prevented developing complex human architectures. This review substantiates the dexterity of additive manufacturing in utilizing biomimetics to 3D print ceramic, polymer, and metal implants with excellent resemblance to natural tissue. It also cites some clinical references of experimental and commercial approaches employing biomimetic 3D printing of implants.

scholarly journals ADDITIVE MANUFACTURING - APPLICATION OPPORTUNITIES FOR THE AVIATION INDUSTRY

2015 ◽  
Vol 6 (2) ◽  
pp. 63-86
Author(s):  
Dipesh Dhital ◽  
Yvonne Ziegler
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Computer Aided Design ◽  
Free Form ◽  
Aviation Industry ◽  
Layer By Layer ◽  
Printing Technology ◽  
3D Printing Technology ◽  
Subtractive Manufacturing ◽  
Aided Design

Additive Manufacturing also known as 3D Printing is a process whereby a real object of virtually any shape can be created layer by layer from a Computer Aided Design (CAD) model. As opposed to the conventional Subtractive Manufacturing that uses cutting, drilling, milling, welding etc., 3D printing is a free-form fabrication process and does not require any of these processes. The 3D printed parts are lighter, require short lead times, less material and reduce environmental footprint of the manufacturing process; and is thus beneficial to the aerospace industry that pursues improvement in aircraft efficiency, fuel saving and reduction in air pollution. Additionally, 3D printing technology allows for creating geometries that would be impossible to make using moulds and the Subtractive Manufacturing of drilling/milling. 3D printing technology also has the potential to re-localize manufacturing as it allows for the production of products at the particular location, as and when required; and eliminates the need for shipping and warehousing of final products.

Thermoplastic 3D Printing-An Additive Manufacturing Method for Producing Dense Ceramics

2014 ◽  
Vol 12 (1) ◽  
pp. 26-31 ◽  
Author(s):  
Uwe Scheithauer ◽  
Eric Schwarzer ◽  
Hans-Jürgen Richter ◽  
Tassilo Moritz
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Manufacturing Method

Stress-Strain Behavior of an Octahedral and Octet-Truss Lattice Structure Fabricated Using the CLIP Technology

2017 ◽  
Vol 1142 ◽  
pp. 245-249 ◽  
Author(s):  
Anil Saigal ◽  
John Tumbleston
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Lattice Structure ◽  
Liquid Interface ◽  
Layer By Layer ◽  
Stress Strain ◽  
Strain Behavior ◽  
Octet Truss ◽  
Continuous Liquid Interface Production ◽  
Similar Density

In the rapidly growing field of additive manufacturing (AM), the focus in recent years has shifted from prototyping to manufacturing fully functional, ultralight, ultrastiff end-use parts. This research investigates the stress-strain behavior of an octahedral-and octet-truss lattice structured polyacrylate fabricated using Continuous Liquid Interface Production (CLIP) technology based on 3D printing and additive manufacturing processes. Continuous Liquid Interface Production (CLIP) is a breakthrough technology that grows parts instead of printing them layer by layer. Lattice structures such as the octahedral-and octet-truss lattice have recently attracted a lot of attention since they are often structurally more efficient than foams of a similar density made from the same material, and the ease with which these structures can now be produced using 3D printing and additive manufacturing. This research investigates the stress-strain behavior under compression of an octahedral-and octet-truss lattice structured polyacrylate fabricated using CLIP technology

A mini-review of embedded 3D printing: supporting media and strategies

2020 ◽  
Vol 8 (46) ◽  
pp. 10474-10486
Author(s):  
Jingzhou Zhao ◽  
Nongyue He
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Manufacturing Method ◽  
Material Extrusion

Embedded 3D printing is an additive manufacturing method based on a material extrusion strategy.

scholarly journals Fabrication of Demineralized Bone Matrix/Polycaprolactone Composites Using Large Area Projection Sintering (LAPS)

2019 ◽  
Vol 3 (2) ◽  
pp. 30 ◽  
Author(s):  
Mohsen Ziaee ◽  
Rebecca Hershman ◽  
Ayesha Mahmood ◽  
Nathan B. Crane
Keyword(s):  
Additive Manufacturing ◽  
Cancellous Bone ◽  
Demineralized Bone Matrix ◽  
Bone Matrix ◽  
Bone Allograft ◽  
Layer By Layer ◽  
Large Area ◽  
Manufacturing Method ◽  
Synthetic Scaffolds ◽  
Demineralized Bone

Cadaveric decellularized bone tissue is utilized as an allograft in many musculoskeletal surgical procedures. Typically, the allograft acts as a scaffold to guide tissue regeneration with superior biocompatibility relative to synthetic scaffolds. Traditionally these scaffolds are machined into the required dimensions and shapes. However, the geometrical simplicity and, in some cases, limited dimensions of the donated tissue restrict the use of allograft scaffolds. This could be overcome by additive manufacturing using granulated bone that is both decellularized and demineralized. In this study, the large area projection sintering (LAPS) method is evaluated as a fabrication method to build porous structures composed of granulated cortical bone bound by polycaprolactone (PCL). This additive manufacturing method utilizes visible light to selectively cure the deposited material layer-by-layer to create 3D geometry. First, the spreading behavior of the composite mixtures is evaluated and the conditions to attain improved powder bed density to fabricate the test specimens are determined. The tensile strength of the LAPS fabricated samples in both dry and hydrated states are determined and compared to the demineralized cancellous bone allograft and the heat treated demineralized-bone/PCL mixture in mold. The results indicated that the projection sintered composites of 45–55 wt %. Demineralized bone matrix (DBM) particulates produced strength comparable to processed and demineralized cancellous bone.

scholarly journals Investigation of a Short Carbon Fibre-Reinforced Polyamide and Comparison of Two Manufacturing Processes: Fused Deposition Modelling (FDM) and Polymer Injection Moulding (PIM)

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 672 ◽  
Author(s):  
Elena Verdejo de Toro ◽  
Juana Coello Sobrino ◽  
Alberto Martínez Martínez ◽  
Valentín Miguel Eguía ◽  
Jorge Ayllón Pérez
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
3D Printing ◽  
Injection Moulding ◽  
New Technologies ◽  
Mechanical Response ◽  
Fused Deposition Modelling ◽  
Layer By Layer ◽  
Polymer Injection ◽  
Fused Deposition

New technologies are offering progressively more effective alternatives to traditional ones. Additive Manufacturing (AM) is gaining importance in fields related to design, manufacturing, engineering and medicine, especially in applications which require complex geometries. Fused Deposition Modelling (FDM) is framed within AM as a technology in which, due to their layer-by-layer deposition, thermoplastic polymers are used for manufacturing parts with a high degree of accuracy and minimum material waste during the process. The traditional technology corresponding to FDM is Polymer Injection Moulding, in which polymeric pellets are injected by pressure into a mould using the required geometry. The increasing use of PA6 in Additive Manufacturing makes it necessary to study the possibility of replacing certain parts manufactured by injection moulding with those created using FDM. In this work, PA6 was selected due to its higher mechanical properties in comparison with PA12. Moreover, its higher melting point has been a limitation for 3D printing technology, and a further study of composites made of PA6 using 3D printing processes is needed. Nevertheless, analysis of the mechanical response of standardised samples and the influence of the manufacturing process on the polyamide’s mechanical properties needs to be carried out. In this work, a comparative study between the two processes was conducted, and conclusions were drawn from an engineering perspective.

3D Printing for Manufacturing Antique and Modern Musical Instrument Parts

2016 ◽  
Author(s):  
Frank Celentano ◽  
Nicholas May ◽  
Edward Simoneau ◽  
Richard DiPasquale ◽  
Zahra Shahbazi ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Cloud Model ◽  
Low Cost ◽  
Sound Quality ◽  
Musical Instrument ◽  
Original Design ◽  
Manufacturing Method ◽  
3D Print ◽  
3D Printed

Professional musicians today often invest in obtaining antique or vintage instruments. These pieces can be used as collector items or more practically, as performance instruments to give a unique sound of a past music era. Unfortunately, these relics are rare, fragile, and particularly expensive to obtain for a modern day musician. The opportunity to reproduce the sound of an antique instrument through the use of additive manufacturing (3D printing) can make this desired product significantly more affordable. 3D printing allows for duplication of unique parts in a low cost and environmentally friendly method, due to its minimal material waste. Additionally, it allows complex geometries to be created without the limitations of other manufacturing techniques. This study focuses on the primary differences, particularly sound quality and comfort, between saxophone mouthpieces that have been 3D printed and those produced by more traditional methods. Saxophone mouthpieces are commonly derived from a milled blank of either hard rubber, ebonite or brass. Although 3D printers can produce a design with the same or similar materials, they are typically created in a layered pattern. This can potentially affect the porosity and surface of a mouthpiece, ultimately affecting player comfort and sound quality. To evaluate this, acoustic tests will be performed. This will involve both traditionally manufactured mouthpieces and 3D prints of the same geometry created from x-ray scans obtained using a ZEISS Xradia Versa 510. The scans are two dimensional images which go through processes of reconstruction and segmentation, which is the process of assigning material to voxels. The result is a point cloud model, which can be used for 3D printing. High quality audio recordings of each mouthpiece will be obtained and a sound analysis will be performed. The focus of this analysis is to determine what qualities of the sound are changed by the manufacturing method and how true the sound of a 3D printed mouthpiece is to its milled counterpart. Additive manufacturing can lead to more inconsistent products of the original design due to the accuracy, repeatability and resolution of the printer, as well as the layer thickness. In order for additive manufacturing to be a common practice of mouthpiece manufacturing, the printer quality must be tested for its precision to an original model. The quality of a 3D print can also have effects on the comfort of the player. Lower quality 3D prints have an inherent roughness which can cause discomfort and difficulty for the musician. This research will determine the effects of manufacturing method on the sound quality and overall comfort of a mouthpiece. In addition, we will evaluate the validity of additive manufacturing as a method of producing mouthpieces.

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