scholarly journals Simulation of the Mechanical Behaviour of Metal Gyroids for Bone Tissue Application

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4808
Author(s):  
Fabrizia Caiazzo ◽  
Diego Gonzalo Guillen ◽  
Vittorio Alfieri
Keyword(s):  
Numerical Simulation ◽  
Additive Manufacturing ◽  
Bone Tissue ◽  
Mechanical Behaviour ◽  
Complex Geometries ◽  
Lightweight Structures ◽  
Actual Outcome ◽  
Valid Solution ◽  
Experimental Effort ◽  
Compressive Tests

Additive manufacturing is a valid solution to build complex geometries, including lightweight structures. Among these, gyroids offer a viable concept for bone tissue application, although many preliminary trials would be required to validate the design before actual implantation. In this frame, this study is aimed at presenting the background and the steps to build a numerical simulation to extract the mechanical behaviour of the structure, thus reducing the experimental effort. The results of the simulation are compared to the actual outcome resulting from quasi-static compressive tests and the effectiveness of the model is measured with reference to similar studies presented in the literature about other lightweight structures.

Numerical Simulation of Flow in Complex Geometries by Using Smoothed Particle Hydrodynamics

2020 ◽  
Vol 59 (40) ◽  
pp. 18236-18246
Author(s):  
Tianwen Dong ◽  
Yadong He ◽  
Jianchun Wu ◽  
Shiyu Jiang ◽  
Xingyuan Huang ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Smoothed Particle Hydrodynamics ◽  
Complex Geometries ◽  
Particle Hydrodynamics ◽  
Smoothed Particle

scholarly journals VOLCO-X: numerical simulation of material distribution and voids in extrusion additive manufacturing

2021 ◽  
pp. 101900
Author(s):  
Rafael Quelho de Macedo ◽  
Rafael Thiago Luiz Ferreira ◽  
Andrew Gleadall ◽  
Ian Ashcroft
Keyword(s):  
Numerical Simulation ◽  
Additive Manufacturing ◽  
Material Distribution

scholarly journals An Additively Manufactured Titanium Alloy in the Focus of Metallography

2021 ◽  
Vol 58 (1) ◽  
pp. 4-31
Author(s):  
C. Fleißner-Rieger ◽  
T. Pogrielz ◽  
D. Obersteiner ◽  
T. Pfeifer ◽  
H. Clemens ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Microstructural Analysis ◽  
Microstructural Characterization ◽  
Melting Process ◽  
Manufacturing Processes ◽  
Ingot Metallurgy ◽  
Lightweight Structures ◽  
Metallographic Preparation ◽  
Fine Structures ◽  
Specific Material

Abstract Additive manufacturing processes allow the production of geometrically complex lightweight structures with specific material properties. However, by contrast with ingot metallurgy methods, the manufacture of components using this process also brings about some challenges. In the field of microstructural characterization, where mostly very fine structures are analyzed, it is thus indispensable to optimize the classic sample preparation process and to furthermore implement additional preparation steps. This work focuses on the metallography of additively manufactured Ti‑6Al‑4V components produced in a selective laser melting process. It offers a guideline for the metallographic preparation along the process chain of additive manufacturing from the metal powder characterization to the macro- and microstructural analysis of the laser melted sample. Apart from developing preparation parameters, selected etching methods were examined with regard to their practicality.

scholarly journals An Optimization Workflow in Design for Additive Manufacturing

2021 ◽  
Vol 11 (6) ◽  
pp. 2572
Author(s):  
Stefano Rosso ◽  
Federico Uriati ◽  
Luca Grigolato ◽  
Roberto Meneghello ◽  
Gianmaria Concheri ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Structural Optimization ◽  
Geometric Model ◽  
Complex Geometries ◽  
Design Phase ◽  
Design For Additive Manufacturing ◽  
Engineering Software ◽  
Embodiment Design ◽  
Pros And Cons

Additive Manufacturing (AM) brought a revolution in parts design and production. It enables the possibility to obtain objects with complex geometries and to exploit structural optimization algorithms. Nevertheless, AM is far from being a mature technology and advances are still needed from different perspectives. Among these, the literature highlights the need of improving the frameworks that describe the design process and taking full advantage of the possibilities offered by AM. This work aims to propose a workflow for AM guiding the designer during the embodiment design phase, from the engineering requirements to the production of the final part. The main aspects are the optimization of the dimensions and the topology of the parts, to take into consideration functional and manufacturing requirements, and to validate the geometric model by computer-aided engineering software. Moreover, a case study dealing with the redesign of a piston rod is presented, in which the proposed workflow is adopted. Results show the effectiveness of the workflow when applied to cases in which structural optimization could bring an advantage in the design of a part and the pros and cons of the choices made during the design phases were highlighted.

scholarly journals Application of an Additive Manufactured Hybrid Metal/Composite Shock Absorber Panel to a Military Seat Ejection System

2021 ◽  
Vol 11 (14) ◽  
pp. 6473
Author(s):  
Valerio Acanfora ◽  
Chiara Corvino ◽  
Salvatore Saputo ◽  
Andrea Sellitto ◽  
Aniello Riccio
Keyword(s):  
Numerical Simulation ◽  
Additive Manufacturing ◽  
Total Mass ◽  
Shock Absorber ◽  
Metal Composite ◽  
Plastic Deformations ◽  
Shock Absorbers ◽  
Numerical Assessment ◽  
Lattice Core ◽  
Ejection Phase

In this work, a preliminary numerical assessment on the application of an additive manufactured hybrid metal/composite shock absorber panels to a military seat ejection system, has been carried out. The innovative character of the shock absorber concept investigated is that the absorbing system has a thickness of only 6 mm and is composed of a pyramid-shaped lattice core that, due to its small size, can only be achieved by additive manufacturing. The mechanical behaviour of these shock absorber panels has been examined by measuring their ability to absorb and dissipate the energy generated during the ejection phase into plastic deformations, thus reducing the loads acting on pilots. In this paper the effectiveness of a system composed of five hybrid shock absorbers, with very thin thickness in order to be easily integrated between the seat and the aircraft floor, has been numerically studied by assessing their ability to absorb the energy generated during the primary ejection phase. To accomplish this, a numerical simulation of the explosion has been performed and the energy absorbed by the shock-absorbing mechanism has been assessed. The performed analysis demonstrated that the panels can absorb more than 60% of the energy generated during the explosion event while increasing the total mass of the pilot-seat system by just 0.8%.

scholarly journals Additive Manufacturing of Ti-Based Intermetallic Alloys: A Review and Conceptualization of a Next-Generation Machine

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4317
Author(s):  
Thywill Cephas Dzogbewu ◽  
Willie Bouwer du Preez
Keyword(s):  
Heat Treatment ◽  
High Temperature ◽  
Additive Manufacturing ◽  
Complex Geometries ◽  
Intermetallic Alloys ◽  
Tial Alloys ◽  
Conventional Methods ◽  
Manufacturing Technologies ◽  
In Situ Heat Treatment

TiAl-based intermetallic alloys have come to the fore as the preferred alloys for high-temperature applications. Conventional methods (casting, forging, sheet forming, extrusion, etc.) have been applied to produce TiAl intermetallic alloys. However, the inherent limitations of conventional methods do not permit the production of the TiAl alloys with intricate geometries. Additive manufacturing technologies such as electron beam melting (EBM) and laser powder bed fusion (LPBF), were used to produce TiAl alloys with complex geometries. EBM technology can produce crack-free TiAl components but lacks geometrical accuracy. LPBF technology has great geometrical precision that could be used to produce TiAl alloys with tailored complex geometries, but cannot produce crack-free TiAl components. To satisfy the current industrial requirement of producing crack-free TiAl alloys with tailored geometries, the paper proposes a new heating model for the LPBF manufacturing process. The model could maintain even temperature between the solidified and subsequent layers, reducing temperature gradients (residual stress), which could eliminate crack formation. The new conceptualized model also opens a window for in situ heat treatment of the built samples to obtain the desired TiAl (γ-phase) and Ti3Al (α2-phase) intermetallic phases for high-temperature operations. In situ heat treatment would also improve the homogeneity of the microstructure of LPBF manufactured samples.

Basis für den industriellen 3D-Druck in Stahl/Basics for industrial 3D printing for steel - Contribution to additive manufacturing of complex products in multi-variant and functional skeleton construction

2017 ◽  
Vol 107 (06) ◽  
pp. 415-419
Author(s):  
M. Hillebrecht ◽  
V. Uhlenwinkel ◽  
A. von Hehl ◽  
H. Zapf ◽  
B. Schob
Keyword(s):  
Additive Manufacturing ◽  
Functional Integration ◽  
Complex Geometries ◽  
Layer By Layer ◽  
Laser Additive Manufacturing ◽  
Complex Products ◽  
Metal Parts ◽  
Laser Joining ◽  
Automation Technology ◽  
Selection Of

Mithilfe laserbasierter generativer Fertigungsverfahren (Laser Additive Manufacturing – LAM) ist es möglich, potentiell komplexe Bauteilgeometrien variantenreich herzustellen. Damit kann Gewicht eingespart werden und Funktionen sind integrierbar. In Kombination mit Automatisierungs- und innovativer Lasertechnik in der Schweiß- und Schneidapplikation lässt sich dieser Prozess wirtschaftlich nutzen. Durch pulverbettbasierte Lasergenerierverfahren können metallische Bauteile schichtweise aufgebaut werden, jedoch ist die Auswahl der Werkstoffe limitiert. Im Forschungsprojekt StaVari (Additive Fertigungsprozesse für komplexe Produkte in variantenreicher und hochfunktionaler Stahlbauweisen) vereinen sich die neuesten Erkenntnisse in Material-, Laser-, Füge- und Automatisierungstechnik, um modernen Anforderungen der Automobilbranche in der Massenfertigung sowie bei der Medizintechnik in der Kleinserie gerecht zu werden.   Laser Additive Manufacturing LAM has the potential to generate complex geometries. Through this weight reduction, functional integration and multi-variant production is possible. In combination with automation and innovative laser technology applicated in welding and cutting, this process can be used economically. With powderbed based laser additive manufacturing metal parts can be built up layer by layer. However selection of available metals is limited. In the project StaVari latest findings in material-, laser-, joining and automation technology are joint by qualified partners to meet modern automotive demands in mass production and medicine technology for small batch series.

Trajectory Planning for Conformal 3D Printing Using Non-Planar Layers

2018 ◽  
Author(s):  
Aniruddha V. Shembekar ◽  
Yeo Jung Yoon ◽  
Alec Kanyuck ◽  
Satyandra K. Gupta
Keyword(s):  
Additive Manufacturing ◽  
Trajectory Planning ◽  
Industrial Robots ◽  
Complex Geometries ◽  
Robot Arm ◽  
Joint Movement ◽  
Tool Orientation ◽  
3D Objects ◽  
Planar Surfaces ◽  
Build Time

Additive manufacturing (AM) technologies have been widely used to fabricate 3D objects quickly and cost-effectively. However, building parts consisting of complex geometries with multiple curvatures can be a challenging process for the traditional AM system whose capability is restricted to planar-layered printing. Using 6-DOF industrial robots for AM overcomes this limitation by allowing materials to deposit on non-planar surfaces with desired tool orientation. In this paper, we present collision-free trajectory planning for printing using non-planar deposition. Trajectory parameters subject to surface curvature are properly controlled to avoid any collision with printing surface. We have implemented our approach by using a 6-DOF robot arm. The complex 3D structures with various curvatures were successfully fabricated, while avoiding any failures in joint movement, holding comparable build time and completing with a satisfactory surface finish.

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