scholarly journals Editorial on Special Issue “Fatigue and Fracture Behaviour of Additive Manufacturing Mechanical Components”

2020 ◽  
Vol 10 (5) ◽  
pp. 1652
Author(s):  
Roberto Citarella ◽  
Paulo M. S. T. De Castro ◽  
Angelo Maligno
Keyword(s):  
Additive Manufacturing ◽  
Stress Concentration ◽  
Residual Stresses ◽  
Mixed Mode Fracture ◽  
Special Issue ◽  
Concentration Effects ◽  
Damage And Fracture ◽  
Fatigue And Fracture ◽  
Mechanical Components ◽  
Am Processes

This Special Issue presents the latest advances in the field of fatigue and fracture performances of additively manufactured mechanical components, including components made of traditional materials (metals, sintered steels, etc.) but undergoing complex loading conditions (multiaxial fatigue and mixed mode fracture). This Special Issue is composed of seven papers covering new insights in structural and material engineering. The advent of additive manufacturing (AM) processes applied to the fabrication of structural components creates the need for design methodologies and structural optimization approaches that take into account the specific characteristics of the process. While AM processes give unprecedented geometrical design freedom, which can result in significant reductions of component weight (e.g., through part count reduction), they have implications in the fatigue and fracture strength due to residual stresses and microstructural features. This is due to stress concentration effects and anisotropy that still need research. The papers of this Special Issue report on numerical simulation and experimental work, or a combination of both. The application of damage and fracture mechanics concepts, the appraisal of stress concentration effects, and the consideration of residual stresses and anisotropic behaviour are tackled for a range of structural applications from biomedical engineering to aerospace components.

scholarly journals Additive Manufacturing in Industry

2021 ◽  
Vol 11 (2) ◽  
pp. 840 ◽  
Author(s):  
Roberto Citarella ◽  
Venanzio Giannella
Keyword(s):  
Additive Manufacturing ◽  
The Other ◽  
Structural Behavior ◽  
Manufacturing Processes ◽  
Structural Components ◽  
Special Issue ◽  
Concentration Effects ◽  
Fatigue And Fracture ◽  
Design Freedom ◽  
Am Processes

The advent of additive manufacturing (AM) processes applied to the fabrication of structural components has created the need for design methodologies and structural optimization approaches that take into account the specific characteristics of the fabrication process. While AM processes give unprecedented geometrical design freedom, which can result in significant reductions in the components’ weight (e.g., through part count reduction), on the other hand, they have implications for the fatigue and fracture strength, because of residual stresses and microstructural features. This is due to stress concentration effects, anisotropy, distortions and defects whose effects still need investigation. This Special Issue aims at gathering together research investigating the different features of AM processes with relevance for their structural behavior, particularly, but not exclusively, from the viewpoints of fatigue, fracture and crash behavior. Although the focus of this Special Issue is on AM, articles dealing with other manufacturing processes with related analogies can also be included, in order to establish differences and possible similarities.

Surface Hardening

2015 ◽  
pp. 499-549
Keyword(s):  
Residual Stresses ◽  
Induction Heating ◽  
Surface Hardening ◽  
Contact Fatigue ◽  
Surface Oxidation ◽  
Surface Treatments ◽  
Bending Fatigue ◽  
Fatigue And Fracture ◽  
Flame Hardening ◽  
Mechanical Components

Mechanical components often require surface treatments to meet application demands. This chapter describes several surface hardening treatments for steel and their effect on microstructure, composition, and properties. It discusses flame hardening, induction heating, carburizing, nitriding, carbonitriding, and nitrocarburizing. The discussion on carburizing addresses several interrelated factors, including processing principles, alloying, surface oxidation, residual stresses, bending fatigue, contact fatigue, and fracture.

scholarly journals Special Issue on Materials Development by Additive Manufacturing Techniques

2020 ◽  
Vol 10 (15) ◽  
pp. 5119
Author(s):  
Alberta Aversa ◽  
Paolo Fino
Keyword(s):  
Additive Manufacturing ◽  
Special Issue ◽  
Production Lines ◽  
Materials Development ◽  
Building Conditions ◽  
Materials Properties ◽  
Industrial Manufacturing ◽  
Research Activities ◽  
Manufacturing Techniques ◽  
Am Processes

Additive manufacturing (AM) processes are steadily gaining attention from many industrial fields, as they are revolutionizing components’ designs and production lines. However, the full application of these technologies to industrial manufacturing has to be supported by the study of the AM materials’ properties and their correlations with the feedstock and the building conditions. Furthermore, nowadays, only a limited number of materials processable by AM are available on the market. It is, therefore, fundamental to widen the materials’ portfolio and to study and develop new materials that can take advantage of these unique building processes. The present special issue collects recent research activities on these topics.

The Influence of Loads Superposition, Deterioration Due to Cracks and Residual Stresses on the Strength of Tubular Junction

2017 ◽  
Vol 68 (6) ◽  
pp. 1267-1273
Author(s):  
Valeriu V. Jinescu ◽  
Angela Chelu ◽  
Gheorghe Zecheru ◽  
Alexandru Pupazescu ◽  
Teodor Sima ◽  
...  
Keyword(s):  
Stress Concentration ◽  
Residual Stresses ◽  
Bending Moment ◽  
Combined Loading ◽  
Torsional Moment ◽  
Calculation Methods ◽  
State Of Stress ◽  
Cracked Structures ◽  
Total Participation ◽  
Theoretical Results

In the paper the interaction of several loads like pressure, axial force, bending moment and torsional moment are analyzed, taking into account the deterioration due to cracks and the influence of residual stresses. A nonlinear, power law, of structure material is considered. General relationships for total participation of specific energies introduced in the structure by the loads, as well as for the critical participation have been proposed. On these bases: - a new strength calculation methods was developed; � strength of tubular cracked structures and of cracked tubular junction subjected to combined loading and strength were analyzed. Relationships for critical state have been proposed, based on dimensionless variables. These theoretical results fit with experimental date reported in literature. On the other side stress concentration coefficients were defined. Our one experiments onto a model of a pipe with two opposite nozzles have been achieved. Near one of the nozzles is a crack on the run pipe. Trough the experiments the state of stress have been obtained near the tubular junction, near the tip of the crack and far from the stress concentration points. On this basis the stress concentration coefficients were calculated.

scholarly journals MODEL-BASED DESIGN OF AM COMPONENTS TO ENABLE DECENTRALIZED DIGITAL MANUFACTURING SYSTEMS

2021 ◽  
Vol 1 ◽  
pp. 2127-2136
Author(s):  
Olivia Borgue ◽  
John Stavridis ◽  
Tomas Vannucci ◽  
Panagiotis Stavropoulos ◽  
Harry Bikas ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Systems ◽  
Production Systems ◽  
Data Generation ◽  
Production Networks ◽  
Model Based ◽  
Manufacturing Technologies ◽  
Am Processes ◽  
Final Consumer

AbstractAdditive manufacturing (AM) is a versatile technology that could add flexibility in manufacturing processes, whether implemented alone or along other technologies. This technology enables on-demand production and decentralized production networks, as production facilities can be located around the world to manufacture products closer to the final consumer (decentralized manufacturing). However, the wide adoption of additive manufacturing technologies is hindered by the lack of experience on its implementation, the lack of repeatability among different manufacturers and a lack of integrated production systems. The later, hinders the traceability and quality assurance of printed components and limits the understanding and data generation of the AM processes and parameters. In this article, a design strategy is proposed to integrate the different phases of the development process into a model-based design platform for decentralized manufacturing. This platform is aimed at facilitating data traceability and product repeatability among different AM machines. The strategy is illustrated with a case study where a car steering knuckle is manufactured in three different facilities in Sweden and Italy.

scholarly journals Substrate design to minimize residual stresses in Directed Energy Deposition AM processes

2021 ◽  
Vol 202 ◽  
pp. 109525
Author(s):  
Xufei Lu ◽  
Michele Chiumenti ◽  
Miguel Cervera ◽  
Junjie Li ◽  
Xin Lin ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Energy Deposition ◽  
Directed Energy Deposition ◽  
Directed Energy ◽  
Am Processes

Preface to the special issue ‘Additive Manufacturing’

2021 ◽  
Vol 191 ◽  
pp. 110330
Author(s):  
H.L. Wei ◽  
T. Mukherjee ◽  
T. DebRoy
Keyword(s):  
Additive Manufacturing ◽  
Special Issue

Toward Metamodels for Composable and Reusable Additive Manufacturing Process Models

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Paul Witherell ◽  
Shaw Feng ◽  
Timothy W. Simpson ◽  
David B. Saint John ◽  
Pan Michaleris ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Metal Powder ◽  
Manufacturing Process ◽  
Process Model ◽  
Model Development ◽  
Process Models ◽  
Powder Bed Fusion ◽  
Powder Bed ◽  
Future Work ◽  
Am Processes

In this paper, we advocate for a more harmonized approach to model development for additive manufacturing (AM) processes, through classification and metamodeling that will support AM process model composability, reusability, and integration. We review several types of AM process models and use the direct metal powder bed fusion AM process to provide illustrative examples of the proposed classification and metamodel approach. We describe how a coordinated approach can be used to extend modeling capabilities by promoting model composability. As part of future work, a framework is envisioned to realize a more coherent strategy for model development and deployment.

Recent Developments of the Multiphysics Discrete Element Method for Additive Manufacturing Modeling and Simulation

2017 ◽  
Author(s):  
John C. Steuben ◽  
Athanasios P. Iliopoulos ◽  
John G. Michopoulos
Keyword(s):  
Additive Manufacturing ◽  
Discrete Element Method ◽  
Discrete Element ◽  
Additive Manufacture ◽  
Computational Tools ◽  
Computational Performance ◽  
Macro Scale ◽  
Recent Developments ◽  
Am Processes ◽  
Element Method

Recent years have seen a sharp increase in the development and usage of Additive Manufacturing (AM) technologies for a broad range of scientific and industrial purposes. The drastic microstructural differences between materials produced via AM and conventional methods has motivated the development of computational tools that model and simulate AM processes in order to facilitate their control for the purpose of optimizing the desired outcomes. This paper discusses recent advances in the continuing development of the Multiphysics Discrete Element Method (MDEM) for the simulation of AM processes. This particle-based method elegantly encapsulates the relevant physics of powder-based AM processes. In particular, the enrichment of the underlying constitutive behaviors to include thermoplasticity is discussed, as are methodologies for modeling the melting and re-solidification of the feedstock materials. Algorithmic improvements that increase computational performance are also discussed. The MDEM is demonstrated to enable the simulation of the additive manufacture of macro-scale components. Concluding remarks are given on the tasks required for the future development of the MDEM, and the topic of experimental validation is also discussed.

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