A Network Based Modelling Approach Using the Dimensional Analysis Conceptual Modeling (DACM) Framework for Additive Manufacturing Technologies

Author(s):  
Hossein Mokhtarian ◽  
Eric Coatanéa ◽  
Henri Paris ◽  
Tuomas Ritola ◽  
Asko Ellman ◽  
...  

The application of additive manufacturing technologies in the industry is growing fast. This leads to an increasing need for reliable modeling techniques in the field of additive manufacturing. A methodology is proposed to systematically assess the influence of process parameters on the final characteristics of additively manufactured parts. The current study aims at presenting a theoretical framework dedicated to the modeling of the additive manufacturing technology. More specifically, the framework is used in the context of the study to plan and optimize the experimental process to minimize the amount of experiments required to populate the model. The framework presented is based on the Dimensional Analysis Conceptual Modelling framework (DACM). DACM is an approach supporting the production of models. This approach is designing networks representing a system architecture and behavior using an approach sharing similarities with neural networks. Based on the proposed approach, it is possible to detect where supplementary experimental data have to be collected to complete the model generated by the DACM approach. The modeling of the Direct Material Deposition process is conducted as an illustrative case study. The scope of the approach is vast and supported by validated scientific methods combined to form the core of the DACM method. The DACM framework is step by step extracting information from a description of the system architecture to create semi-automatically a model that can be simulated and used for multiple types of analyses associated for example with innovation and design improvement. The current paper will focus on the usage of the DACM framework, recently developed in a project, in the field of additive manufacturing.

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 811 ◽  
Author(s):  
Jørgen Blindheim ◽  
Torgeir Welo ◽  
Martin Steinert

Hybrid Metal Extrusion & Bonding Additive Manufacturing (HYB-AM) is a hybrid manufacturing technology for the deposition of layered metal structures. This new deposition process is a complex metal forming operation, yet there is significant lack of knowledge regarding the governing mechanisms. In this work, we have used finite element analysis (FEA) to study material flow in the extruder, as well as the conditions at the interfaces of the deposited extrudate and the substrate, aiming to identify and characterize the process parameters involved. Analysis of the material flow shows that the extrusion pressure is virtually independent of the deposition rate. Furthermore, from the simulations of the material deposition sequence, it is clearly visible how the contact pressure at the interface will drop below the bonding threshold if the feed speed is too high relative to the material flow through the die. The reduced pressure also leads to the formation of a ‘gas-pocket’ inside the die, thus further degrading the conditions for bonding. The analyses of the process have provided valuable insights for the further development and industrialization of the process.


Author(s):  
Samuel Magalhães ◽  
Manuel Sardinha ◽  
Carlos Vicente ◽  
Marco Leite ◽  
Relógio Ribeiro ◽  
...  

Additive manufacturing technologies are becoming increasingly popular due to their advantages over traditional subtracting manufacturing technologies. Despite advances in this field, fixed and maintenance costs for additive manufacturing with metals remain high. The introduction of low-cost metal machines in the additive manufacturing market considerably reduces the cost of acquiring and maintaining this type of equipment. This work aims to establish the process requirements for a low-cost selective powder deposition process, and validate it through the production of specimens in the laboratory and evaluate their mechanical properties. Tin bronze specimens were produced under different manufacturing conditions, namely powder dimensions, type of crucible and coke, firing segments and casting strategy. The morphology and chemical composition of the specimens were carried out combining the scanning electron microscopy and energy dispersive X-Ray spectroscopy techniques, respectively. It was observed that crucibles and coke with impurities that react with the metal powders and infill in a reducing atmosphere have influence in the final quality of parts. Tested samples displayed high variability of results which can be correlated with different manufacturing conditions. The selection of the appropriate print parameters led to the manufacture of tin bronze specimens with mechanical properties comparable to those reported in the literature. Overall, low-cost selective powder deposition is a promising technology, if identified manufacturing issues are addressed.


Author(s):  
Anirudh Krishnakumar ◽  
Krishnan Suresh ◽  
Aaditya Chandrasekar

There is significant interest today in the finite element simulation of various Additive Manufacturing (AM) processes. AM simulation is time-dependent, inherently non-linear, and involves multiple physics. In addition, repeated meshing and insertion of new elements during material deposition can pose significant implementation challenges. Currently, AM simulation is handled either through a ‘quiet’ approach or an ‘inactive’ approach. In the quiet approach, all finite elements within the workspace are assembled into the global stiffness matrix, and the elements yet to be deposited are assigned ‘void’ material properties. In the inactive approach, only the elements that have been deposited are assembled into the global stiffness matrix. The advantages and disadvantages of the two methods are well documented. In this paper, we propose a voxel-based, assembly-free framework for AM simulation. This framework presents several advantages including. (1) The workspace is meshed only once at the start of the simulation, (2) addition and deletion of elements is trivial, (3) reduced memory requirement as the global stiffness matrix is never assembled and (4) the underlying linear systems of equations can be solved efficiently through assembly-free methods. We demonstrate the framework here by simulating transient non-linear thermal behaviour of a laser deposition process, with material deposition.


2021 ◽  
Author(s):  
Jayaprakash Sharma Panchagnula ◽  
Suryakumar Simhambhatla

Abstract Amongst various additive manufacturing (AM) techniques for realizing the complex metallic objects, weld deposition (arc) based directed energy AM technique is attaining the more focus over commercially available powder bed fusion techniques. This is due to the capability of high deposition rates, high power and material utilization, simpler setup and less initial investment of arc based AM. Nevertheless, realization of sudden overhanging features through arc based weld deposition techniques is still a challenging task due to the necessity of support structures. The present work describes a novel methodology for producing complex metallic objects with sudden overhangs without using supports. This is possible by re-orienting the workpiece and/or deposition head at every instance using higher order kinematics (5-axis setup) to make sure the overhanging feature is in-line to the deposition direction. The proposed technique identifies the sudden overhangs form a CAD model (.stl) and generates an orthogonal tool path for deposition of the same. To validate this technique, objects with sudden overhangs (illustrative case studies) have been taken up for deposition. An In-house MATLAB routine has developed and presented for performing the same. Although this technique is suitable for any deposition process, it has been demonstrated using gas metal arc welding (GMAW) based weld-deposition, where the raw material to be deposited is in the form of a welding wire.


2021 ◽  
Vol 33 (1) ◽  
pp. 012021
Author(s):  
Jonathan Schaible ◽  
Lennart Sayk ◽  
Thomas Schopphoven ◽  
Johannes Henrich Schleifenbaum ◽  
Constantin Häfner

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1160 ◽  
Author(s):  
Federico Mazzucato ◽  
Alberta Aversa ◽  
Roberto Doglione ◽  
Sara Biamino ◽  
Anna Valente ◽  
...  

In blown powder additive manufacturing technologies the geometrical stability of the built parts is more complex with respect to more conventional powder bed processes. Because of this reason, in order to select the most suitable building parameters, it is important to investigate the shape and the properties of the single metal bead formation and the effect that a scan track has on the nearby ones. In the present study, a methodology to identify an appropriate laser metal deposition process window was introduced, and the effect of the building parameters on the geometry of circular steel samples was investigated. The effect of the scanning strategy on the deposited part was also investigated. This work draws the attention to the importance of the obtainment of the most suitable melt pool shape, demonstrating that the laser power and the scanning strategy have a strong influence not only on the shape but also on the mechanical properties of the final component.


Author(s):  
V. Senthilkumar ◽  
Velmurugan C. ◽  
K. R. Balasubramanian ◽  
M. Kumaran

Additive manufacturing (AM) technology can be employed to produce multimaterial parts. In this approach, multiple types of materials are used for the fabrication of a single part. Custom-built functionally graded, heterogeneous, or porous structures and composite materials can be fabricated thorough this process. In this method, metals, plastics, and ceramics have been used with suitable AM methods to obtain multi-material products depending on functional requirements. The process of making composite materials by AM can either be performed during the material deposition process or by a hybrid process in which the combination of different materials can be performed before or after AM as a previous or subsequent stage of production of a component. Composite processes can be employed to produce functionally graded materials (FGM).


Author(s):  
J. Choi

Laser aided direct metal/material deposition (DMD) process, one of the technologies based on laser cladding, has demonstrated the ability to make a metal component directly from a 3-D CAD model. DMD process is achieved with a laser system combined with a NC machine tool or laser-robot system. Making metallic parts directly, designer can reduce unnecessary steps such as mock-up and molding. In the sense, DMD process is rather a rapid production technique than a rapid prototyping process. With continued advancement, DMD process, one of the leading solid freeform fabrication techniques, has demonstrated the ability to make a metal part with heterogeneous components directly from a CAD model. One unique advantage of the process is that building different metallic parts in same object can be achieved alternating metal powders. The advantage gives designers better quality of products than others can offer. Another attractive point is that some features such as cooling channel, heat sinks, sensors, fibers, and even hard phases for composites can be embedded during the process. This paper summarizes the fundamentals of the process, process control and influence of process parameters, and reports some examples produced utilizing the technique with the characteristics of fabricated parts.


2021 ◽  
Vol 1 ◽  
pp. 231-240
Author(s):  
Laura Wirths ◽  
Matthias Bleckmann ◽  
Kristin Paetzold

AbstractAdditive Manufacturing technologies are based on a layer-by-layer build-up. This offers the possibility to design complex geometries or to integrate functionalities in the part. Nevertheless, limitations given by the manufacturing process apply to the geometric design freedom. These limitations are often unknown due to a lack of knowledge of the cause-effect relationships of the process. Currently, this leads to many iterations until the final part fulfils its functionality. Particularly for small batch sizes, producing the part at the first attempt is very important. In this study, a structured approach to reduce the design iterations is presented. Therefore, the cause-effect relationships are systematically established and analysed in detail. Based on this knowledge, design guidelines can be derived. These guidelines consider process limitations and help to reduce the iterations for the final part production. In order to illustrate the approach, the spare parts production via laser powder bed fusion is used as an example.


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