scholarly journals Effects of Raster Orientation, Infill Rate and Infill Pattern on the Mechanical Properties of 3D Printed Materials

2017 ◽  
Vol 69 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Cristian Dudescu ◽  
Laszlo Racz

AbstractThree-dimensional printing is an additive manufacturing process that allows rapid design and manufacture of complex component based on computer-aided design models. Compared with some conventional manufacturing processes, additive manufacturing part properties can depend on structural and process parameters rather than purely on material properties. The objectives of the paper are to evaluate the tensile properties of 3D printed components produced using a commercial 3D printer by performing standard tensile tests and to assess the influence of the technological parameters upon mechanical proprieties of printed specimens, considering different printing directions, infill rates and infill patterns. The influence of raster angles is tested through the designed specimens with different transverse plane, they are printed by placing in different angle, including 0°, 30°, 45° and 90°. Specimens with an infill rate varying from 20% to 100% and six different infill patterns has been tested.

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Wiktoria Maria Wojnarowska ◽  
Jakub Najowicz ◽  
Tomasz Piecuch ◽  
Michał Sochacki ◽  
Dawid Pijanka ◽  
...  

Purpose Chicken orthoses that cover the ankle joint area are not commercially available. Therefore, the main purpose of this study is to fabricate a customised temporary Ankle–Foot Orthosis (AFO) for a chicken with a twisted ankle using computer-aided design (CAD) and three-dimensional (3D) printing. The secondary objective of the paper is to present the specific application of Additive Manufacturing (AM) in veterinary medicine. Design/methodology/approach The design process was based on multiple sketches, photos and measurements that were provided by the owner of the animal. The 3D model of the orthosis was made with Autodesk Fusion 360, while the prototype was fabricated using fused deposition modelling (FDM). Evaluation of the AFO was performed using the finite element method. Findings The work resulted in a functional 3D printed AFO for chicken. It was found that the orthosis made with AM provides satisfactory stiffen and a good fit. It was concluded that AM is suitable for custom bird AFO fabrication and, in some respects, is superior to traditional manufacturing methods. It was also concluded that the presented procedure can be applied in other veterinary cases and to other animal species and other parts of their body. AM provides veterinary with a powerful tool for the production of well-fitted and durable orthoses for animals. Research limitations/implications The study does not include the chicken's opinion on the comfort or fit of the manufactured AFO due to communication issues. Evaluation of the final prototype was done by the researchers and the animal owner. Originality/value No evidence was found in the literature on the use of AM for chicken orthosis, so this study is the first to describe such an application of AM. In addition, the study demonstrates the value of AM in veterinary medicine, especially in the production of devices such as orthoses.


Author(s):  
Neeraj Panhalkar ◽  
Ratnadeep Paul ◽  
Sam Anand

Additive manufacturing (AM) is widely used in aerospace, automobile, and medical industries for building highly accurate parts using a layer by layer approach. The stereolithography (STL) file is the standard file format used in AM machines and approximates the three-dimensional (3D) model of parts using planar triangles. However, as the STL file is an approximation of the actual computer aided design (CAD) surface, the geometric errors in the final manufactured parts are pronounced, particularly in those parts with highly curved surfaces. If the part is built with the minimum uniform layer thickness allowed by the AM machine, the manufactured part will typically have the best quality, but this will also result in a considerable increase in build time. Therefore, as a compromise, the part can be built with variable layer thicknesses, i.e., using an adaptive layering technique, which will reduce the part build time while still reducing the part errors and satisfying the geometric tolerance callouts on the part. This paper describes a new approach of determining the variable slices using a 3D k-d tree method. The paper validates the proposed k-d tree based adaptive layering approach for three test parts and documents the results by comparing the volumetric, cylindricity, sphericity, and profile errors obtained from this approach with those obtained using a uniform slicing method. Since current AM machines are incapable of handling adaptive slicing approach directly, a “pseudo” grouped adaptive layering approach is also proposed here. This “clustered slicing” technique will enable the fabrication of a part in bands of varying slice thicknesses with each band having clusters of uniform slice thicknesses. The proposed k-d tree based adaptive slicing approach along with clustered slicing has been validated with simulations of the test parts of different shapes.


3D Printing ◽  
2017 ◽  
pp. 154-171 ◽  
Author(s):  
Rasheedat M. Mahamood ◽  
Esther T. Akinlabi

Laser additive manufacturing is an advanced manufacturing process for making prototypes as well as functional parts directly from the three dimensional (3D) Computer-Aided Design (CAD) model of the part and the parts are built up adding materials layer after layer, until the part is competed. Of all the additive manufacturing process, laser additive manufacturing is more favoured because of the advantages that laser offers. Laser is characterized by collimated linear beam that can be accurately controlled. This chapter brings to light, the various laser additive manufacturing technologies such as: - selective laser sintering and melting, stereolithography and laser metal deposition. Each of these laser additive manufacturing technologies are described with their merits and demerits as well as their areas of applications. Properties of some of the parts produced through these processes are also reviewed in this chapter.


2020 ◽  
Vol 9 (3) ◽  
pp. 832 ◽  
Author(s):  
Dave Chamo ◽  
Bilal Msallem ◽  
Neha Sharma ◽  
Soheila Aghlmandi ◽  
Christoph Kunz ◽  
...  

The use of patient-specific implants (PSIs) in craniofacial surgery is often limited due to a lack of expertise and/or production costs. Therefore, a simple and cost-efficient template-based fabrication workflow has been developed to overcome these disadvantages. The aim of this study is to assess the accuracy of PSIs made from their original templates. For a representative cranial defect (CRD) and a temporo-orbital defect (TOD), ten PSIs were made from polymethylmethacrylate (PMMA) using computer-aided design (CAD) and three-dimensional (3D) printing technology. These customized implants were measured and compared with their original 3D printed templates. The implants for the CRD revealed a root mean square (RMS) value ranging from 1.128 to 0.469 mm with a median RMS (Q1 to Q3) of 0.574 (0.528 to 0.701) mm. Those for the TOD revealed an RMS value ranging from 1.079 to 0.630 mm with a median RMS (Q1 to Q3) of 0.843 (0.635 to 0.943) mm. This study demonstrates that a highly precise duplication of PSIs can be achieved using this template-molding workflow. Thus, virtually planned implants can be accurately transferred into haptic PSIs. This workflow appears to offer a sophisticated solution for craniofacial reconstruction and continues to prove itself in daily clinical practice.


2019 ◽  
Vol 109 (2) ◽  
pp. 166-173 ◽  
Author(s):  
A.B.V. Pettersson ◽  
M. Salmi ◽  
P. Vallittu ◽  
W. Serlo ◽  
J. Tuomi ◽  
...  

Background and Aims: Additive manufacturing or three-dimensional printing is a novel production methodology for producing patient-specific models, medical aids, tools, and implants. However, the clinical impact of this technology is unknown. In this study, we sought to characterize the clinical adoption of medical additive manufacturing in Finland in 2016–2017. We focused on non-dental usage at university hospitals. Materials and Methods: A questionnaire containing five questions was sent by email to all operative, radiologic, and oncologic departments of all university hospitals in Finland. Respondents who reported extensive use of medical additive manufacturing were contacted with additional, personalized questions. Results: Of the 115 questionnaires sent, 58 received answers. Of the responders, 41% identified as non-users, including all general/gastrointestinal (GI) and vascular surgeons, urologists, and gynecologists; 23% identified as experimenters or previous users; and 36% identified as heavy users. Usage was concentrated around the head area by various specialties (neurosurgical, craniomaxillofacial, ear, nose and throat diseases (ENT), plastic surgery). Applications included repair of cranial vault defects and malformations, surgical oncology, trauma, and cleft palate reconstruction. Some routine usage was also reported in orthopedics. In addition to these patient-specific uses, we identified several off-the-shelf medical components that were produced by additive manufacturing, while some important patient-specific components were produced by traditional methodologies such as milling. Conclusion: During 2016–2017, medical additive manufacturing in Finland was routinely used at university hospitals for several applications in the head area. Outside of this area, usage was much less common. Future research should include all patient-specific products created by a computer-aided design/manufacture workflow from imaging data, instead of concentrating on the production methodology.


2019 ◽  
Vol 72 (7) ◽  
pp. 1198-1206 ◽  
Author(s):  
Cheng-I Yen ◽  
Jonathan A. Zelken ◽  
Chun-Shin Chang ◽  
Lun-Jou Lo ◽  
Jui-Yung Yang ◽  
...  

2018 ◽  
Vol 24 (4) ◽  
pp. 709-721 ◽  
Author(s):  
Jiawei Feng ◽  
Jianzhong Fu ◽  
Zhiwei Lin ◽  
Ce Shang ◽  
Bin Li

Purpose T-spline is the latest powerful modeling tool in the field of computer-aided design. It has all the merits of non-uniform rational B-spline (NURBS) whilst resolving some flaws in it. This work applies T-spline surfaces to additive manufacturing (AM). Most current AM products are based on Stereolithograph models. It is a kind of discrete polyhedron model with huge amounts of data and some inherent defects. T-spline offers a better choice for the design and manufacture of complex models. Design/methodology/approach In this paper, a direct slicing algorithm of T-spline surfaces for AM is proposed. Initially, a T-spline surface is designed in commercial software and saved as a T-spline mesh file. Then, a numerical method is used to directly calculate all the slicing points on the surface. To achieve higher manufacturing efficiency, an adaptive slicing algorithm is applied according to the geometrical properties of the T-spline surface. Findings Experimental results indicate that this algorithm is effective and reliable. The quality of AM can be enhanced at both the designing and slicing stages. Originality/value The T-spline and direct slicing algorithm discussed here will be a powerful supplement to current technologies in AM.


2016 ◽  
Vol 100 (7) ◽  
pp. 879-881 ◽  
Author(s):  
Sébastien Ruiters ◽  
Yi Sun ◽  
Stéphan de Jong ◽  
Constantinus Politis ◽  
Ilse Mombaerts

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