Generation of Continuous Toolpaths for Additive Manufacturing Using Implicit Slicing

2021 ◽  
Author(s):  
J. C. Steuben ◽  
J. G. Michopoulos ◽  
A. P. Iliopoulos
Keyword(s):  
Additive Manufacturing ◽  
Test Problem ◽  
Geometric Analysis ◽  
General Purpose ◽  
Geometric Feature ◽  
Strong Impact ◽  
Tool Paths ◽  
Thermosetting Polymers ◽  
Material Systems ◽  
Am Processes

Abstract The generation of footpaths for additive manufacturing (AM), a process commonly known as “slicing,” has a strong impact on the performance of both the associated hardware systems and the resulting objects. Available slicers invariably produce discontinuous tootpaths, featuring jumps or so-catted “travel moves” during which the deposition of material or/and energy must be hatted. For AM processes using slowly solidifying feedstock materials, such as thermosetting polymers or cementitious mixtures such as concrete, these tootpath discontinuities are highly undesirable due to the artifacts they generate. This renders existing sticers difficult to use in such applications, and presents a road-block to the adoption of AM for such material systems. In the present work, this difficulty is addressed by the development of a simple geometric criterion for the existence of continuous tool-paths that are capable of producing a specified input geometry. This development is based on the principles of morphological geometric analysis and graph theory. It is shown that, for any geometric feature with a characteristic thickness at least twice the extrusion width, a continuous toolpath exists. Furthermore, a general-purpose algorithm for continuous toolpath generation, for arbitrarily shaped objects satisfying this criterion, is developed and demonstrated on a representative test problem. Finally, conclusions and the path forward for the usage of this approach with existing AM systems is explored.

Consideration of the Manufacturing Trajectories in a Global Design for Additive Manufacturing Methodology

2012 ◽  
Author(s):  
R. Ponche ◽  
O. Kerbrat ◽  
P. Mognol ◽  
J. Y. Hascoet
Keyword(s):  
Additive Manufacturing ◽  
Cost Reduction ◽  
Design Problem ◽  
Manufacturing Processes ◽  
Strong Impact ◽  
Direct Impact ◽  
Design For Additive Manufacturing ◽  
Physical Phenomena ◽  
Am Processes

Additive Manufacturing (AM) is a new way of part production which opens up new perspectives of conception as mass and cost reduction and increase of functionalities. However these processes have their own characteristics which as for all the manufacturing processes have a direct impact on the manufactured parts quality. Especially, because the manufacturing trajectories have a influence on the physical phenomena during the process, they have also a strong impact on the quality of the produced parts in terms of geometry. In this paper, the choice of manufacturing trajectories and their impacts on the final shape and quality of the parts is integrated into a global Design For Additive Manufacturing (DFAM) methodology which allows to move from functional specifications of a design problem to a proposition of an adapted part for AM processes.

scholarly journals Repairing Ti-6Al-4V aeronautical components with DED additive manufacturing

2020 ◽  
Vol 321 ◽  
pp. 03017
Author(s):  
Matthieu Rauch ◽  
Jean-Yves Hascoët ◽  
Manjaiah Mallaiah
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Industry ◽  
Energy Deposition ◽  
Low Cycle Fatigue ◽  
Direct Energy Deposition ◽  
Tool Paths ◽  
Experimental Campaign ◽  
Direct Energy ◽  
Am Processes ◽  
Optimal Process Parameter

Direct Energy Deposition (DED) processes are Additive Manufacturing (AM) processes that provide new perspectives for the manufacturing industry. In particular the area of component repair could highly benefit from these processes. It is consequently necessary to ensure the ability of DED processes, so that the repaired component can provide the same level of service than a new one. This paper focuses on the repair of Ti-6Al-4V parts by powder based LMD AM and investigates its accuracy, repeatability and reliability. At first, an experimental campaign has been carried out to evaluate the characteristics of as-built material. Optimal process parameter selection is made by a porosity and macrostructure analysis. Tensile properties, Low Cycle Fatigue and crack propagation studies have been done on as-built samples (100% AM) and interface samples (50% AM / 50% substrate). The results compare to wrought alloy and validate the relevance of LMD to produce sound repaired parts. In a second section, the paper proposes a semi automatic repair method of Ti-6Al-4V components: the defect geometry and the CAD model of the part to repair are identified from 3D scanning operations. Adapted additive and machining tool paths are then generated on the selected equipment.

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.

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.

Design and Analysis of Hybrid Fused Filament Fabrication Apparatus for Fabrication of Composites

2021 ◽  
Vol 14 ◽  
Author(s):  
Aniket Yadav ◽  
Piyush Chohan ◽  
Ranvijay Kumar ◽  
Jasgurpreet Singh Chohan ◽  
Raman Kumar
Keyword(s):  
Additive Manufacturing ◽  
Composite Materials ◽  
Design Process ◽  
Low Cost ◽  
Matrix Material ◽  
Fabrication Process ◽  
Layer By Layer ◽  
Fused Filament Fabrication ◽  
Composite Manufacturing ◽  
Tool Paths

Background: Additive manufacturing is the most famous technology which requires materials or composites to be fabricated with layer by layer deposition strategy. Due to its lower cost, higher accuracy and less material wastage; this technology is used in almost every sector. But in many applications there is a need to alter the properties of a product in a certain direction with the help of some reinforcements. With the use of reinforcements, composite layers can be fabricated using additive manufacturing technique which will enhance the directional properties. A novel apparatus is designed to spray the reinforcement material into the printed structures in a very neat and precise manner. This spray nozzle is fully automated, which works according to tool-paths generated by slicing software. The alternate deposition of layers of reinforcement and build materials helped to fabricate customized composite products. Objective: The objective of present study is to design and analyze the working principle of novel technique which has been developed to fabricate composite materials using additive manufacturing. The apparatus is numerically controlled by computer according to CAD data which facilitates the deposition of alternate layers of reinforcement and matrix material. The major challenges during the design process and function of each component has been explored. Methods: The design process is initiated after comprehensive literature review performed to study previous composite manufacturing processes. The recent patents published by different patent offices of the world are studied in detail and analysis has been used to design a low cost composite fabrication apparatus. A liquid dispensing device comprises a storage tank attached with a pump and microprocessor. The microprocessor receives the signal from the computer as per tool paths generated by slicing software which decides the spray of reinforcements on polymer layers. The spraying apparatus moves in coordination with the primary nozzle of the Fused Filament Fabrication process. Results: The hybridization of Fused Filament Fabrication [process with metal spray process has been successfully performed. The apparatus facilitates the fabrication of low cost composite materials along with flexibility of complete customization of composite manufacturing process. The anisotropic behaviour of products can be easily controlled and managed during fabrication which can be used for different applications.

A Scalable Framework for Process-Aware Thermal Simulation of Additive Manufacturing Processes

2021 ◽  
pp. 1-16
Author(s):  
Yaqi Zhang ◽  
Vadim Shapiro ◽  
Paul Witherell
Keyword(s):  
Additive Manufacturing ◽  
Heat Source ◽  
Spatial Data ◽  
Manufacturing Process ◽  
Thermal Simulation ◽  
Physical Parameters ◽  
Moving Heat Source ◽  
Time Step ◽  
Fused Deposition ◽  
Am Processes

Abstract Many additive manufacturing (AM) processes are driven by a moving heat source. Thermal field evolution during the manufacturing process plays an important role in determining both geometric and mechanical properties of the fabricated parts. Thermal simulation of AM processes is challenging due to the geometric complexity of the manufacturing process and inherent computational complexity that requires a numerical solution at every time increment of the process. We propose a new general computational framework that supports scalable thermal simulation at path scale of any AM process driven by a moving heat source. The proposed framework has three novel ingredients. First, the path-level discretization is process-aware, which is based on the manufacturing primitives described by the scan path and the thermal model is formulated directly in terms of manufacturing primitives. Second, a spatial data structure, called contact graph, is used to represent the discretized domain and capture all possible thermal interactions during the simulation. Finally, the simulation is localized based on specific physical parameters of the manufacturing process, requiring at most a constant number of updates at each time step. The latter implies that the constructed simulation not only scales to handle three-dimensional (3D) printed components of arbitrary complexity but also can achieve real-time performance. To demonstrate the efficacy and generality of the framework, it has been successfully applied to build thermal simulations of two different AM processes, fused deposition modeling (FDM) and powder bed fusion (PBF).

Design for Additive Manufacturing in the Cloud Platform

2017 ◽  
Author(s):  
Yuanbin Wang ◽  
Robert Blache ◽  
Xun Xu
Keyword(s):  
Knowledge Management ◽  
Decision Support ◽  
Additive Manufacturing ◽  
Full Advantage ◽  
New Technologies ◽  
Design Stage ◽  
Design For Additive Manufacturing ◽  
Cloud Platform ◽  
Am Processes

Additive manufacturing (AM) has experienced a phenomenal expansion in recent years and new technologies and materials rapidly emerge in the market. Design for Additive Manufacturing (DfAM) becomes more and more important to take full advantage of the capabilities provided by AM. However, most people still have limited knowledge to make informed decisions in the design stage. Therefore, an interactive DfAM system in the cloud platform is proposed to enable people sharing the knowledge in this field and guide the designers to utilize AM efficiently. There are two major modules in the system, decision support module and knowledge management module. A case study is presented to illustrate how this system can help the designers understand the capabilities of AM processes and make rational decisions.

Differential Performance Signature Qualification for Additively Manufactured Parts

2018 ◽  
Author(s):  
John G. Michopoulos ◽  
John C. Steuben ◽  
Athanasios P. Iliopoulos
Keyword(s):  
Additive Manufacturing ◽  
Graphical Representation ◽  
Functional Performance ◽  
Complex Objects ◽  
Aircraft Landing ◽  
Differential Performance ◽  
Aircraft Landing Gear ◽  
Am Processes ◽  
Comparison Measures ◽  
Quantities Of Interest

Additive Manufacturing (AM) technologies and associated processes, enable successive accretion of material to a domain, and permit manufacturing of highly complex objects which would otherwise be unrealizable. However, the material micro- and meso-structures generated by AM processes can differ remarkably from those arising from conventional manufacturing (CM) methods. Often, a consequence of this fact is the sub-standard functional performance of the produced parts that can limit the use of AM in some applications. In the present work, we propose a rapid functional qualification methodology for AM-produced parts based on a concept defined as differential Performance Signature Qualification (dPSQ). The concept of Performance Signature (PerSig) is introduced both as a vector of featured quantities of interest (QoIs), and a graphical representation in the form of radar or spider graph, representing the QoIs associated with the performance of relevant parts. The PerSigs are defined for both the prequalified CM parts and the AM-produced ones. Comparison measures are defined and enable the construction of differential PerSigs (dPerSig) in a manner that captures the differential performance of the AM part vs. the prequalified CM one. The dPerSigs enable AM part qualification based on how their PerSigs are different from those of prequalified CM parts. After defining the steps of the proposed methodology, we describe its application on a part of an aircraft landing gear assembly and demonstrate its feasibility.

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