Numerical simulations of the mesostructure formation in material extrusion additive manufacturing

Serdeczny, Marcin P.; Comminal, Raphaël; Pedersen, David Bue; Spangenberg, Jon

doi:10.1016/j.addma.2019.05.024

Cited by 61 publications

(75 citation statements)

References 48 publications

(59 reference statements)

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“…The normalised layer thickness and the nozzle diameter ratio are employed to quantify the computational model’s geometry. In contrast, the velocity ratio is used to parameterise the amount of extruded materials with reference to the printing speed [ 14 ]. Given that the numerical results presented in dimensionless forms for fixed values of

, and

, the obtained data can be considered equally valid for other simulation cases with various printing speeds nozzle diameters.…”

Section: Methodsmentioning

confidence: 99%

“…Comminal et al [ 19 ] investigated the effects of the layer thickness and the printing speed on the shape of the deposited strand using a 3D CFD model of the strand deposition (assuming a Newtonian fluid); this CFD model was then validated by experiments in [ 8 ]. Serdeczny et al [ 14 ] expanded their research further to model the successive deposition of parallel strands to predict the mesostructure formed. They also acquire information about the porosity, the surface roughness, and the inter-and intra-layer bond line densities of the mesostructures.…”

Section: Introductionmentioning

confidence: 99%

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Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing

et al. 2021

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Material extrusion additive manufacturing (ME-AM) techniques have been recently introduced for core–shell polymer manufacturing. Using ME-AM for core–shell manufacturing offers improved mechanical properties and dimensional accuracy over conventional 3D-printed polymer. Operating parameters play an important role in forming the overall quality of the 3D-printed manufactured products. Here we use numerical simulations within the framework of computation fluid dynamics (CFD) to identify the best combination of operating parameters for the 3D printing of a core–shell polymer strand. The objectives of these CFD simulations are to find strands with an ultimate volume fraction of core polymer. At the same time, complete encapsulations are obtained for the core polymer inside the shell one. In this model, the deposition flow is controlled by three dimensionless parameters: (i) the diameter ratio of core material to the nozzle, d/D; (ii) the normalised gap between the extruder and the build plate, t/D; (iii) the velocity ratio of the moving build plate to the average velocity inside the nozzle, V/U. Numerical results of the deposited strands’ cross-sections demonstrate the effects of controlling parameters on the encapsulation of the core material inside the shell and the shape and size of the strand. Overall we find that the best operating parameters are a diameter ratio of d/D=0.7, a normalised gap of t/D=1, and a velocity ratio of V/U=1.

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, and

, the obtained data can be considered equally valid for other simulation cases with various printing speeds nozzle diameters.…”

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing

et al. 2021

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“…Porosity formation and strand morphology are critical issues in extrusion that affect the part performance and are under significant influence of both the layer thickness and the strand-to-stand distance. It was reported that a lower filament layer thickness and the strand-to-strand distance led to smaller porosity and larger inter- and intra-layer bond line densities [ 19 ].…”

Section: Additive Manufacturing Processesmentioning

confidence: 99%

An Overview of Additive Manufacturing Technologies—A Review to Technical Synthesis in Numerical Study of Selective Laser Melting

et al. 2020

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Additive Manufacturing (AM) processes enable their deployment in broad applications from aerospace to art, design, and architecture. Part quality and performance are the main concerns during AM processes execution that the achievement of adequate characteristics can be guaranteed, considering a wide range of influencing factors, such as process parameters, material, environment, measurement, and operators training. Investigating the effects of not only the influential AM processes variables but also their interactions and coupled impacts are essential to process optimization which requires huge efforts to be made. Therefore, numerical simulation can be an effective tool that facilities the evaluation of the AM processes principles. Selective Laser Melting (SLM) is a widespread Powder Bed Fusion (PBF) AM process that due to its superior advantages, such as capability to print complex and highly customized components, which leads to an increasing attention paid by industries and academia. Temperature distribution and melt pool dynamics have paramount importance to be well simulated and correlated by part quality in terms of surface finish, induced residual stress and microstructure evolution during SLM. Summarizing numerical simulations of SLM in this survey is pointed out as one important research perspective as well as exploring the contribution of adopted approaches and practices. This review survey has been organized to give an overview of AM processes such as extrusion, photopolymerization, material jetting, laminated object manufacturing, and powder bed fusion. And in particular is targeted to discuss the conducted numerical simulation of SLM to illustrate a uniform picture of existing nonproprietary approaches to predict the heat transfer, melt pool behavior, microstructure and residual stresses analysis.

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“…Recently, other researchers have done much work to specifically explore the deposition process in FFF, through numerical simulation [ 14 , 15 , 16 , 17 ] and theoretical analysis [ 18 ]. They have explored the effects of the speed ratio [ 14 , 15 ], viscosity [ 15 ], viscoelasticity [ 16 ], deposition flows [ 17 ], and interlayer contact pressures [ 18 ] on the dimensions of the deposited strands for particular combinations of processing parameters. As indicated in [ 19 ], a simple method is needed to calculate the geometries of the deposited filament for FFF.…”

Section: Introductionmentioning

confidence: 99%

Bonding widths of Deposited Polymer Strands in Additive Manufacturing

et al. 2021

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In this study, we explore the deformation of a polymer extrudate upon the deposition on a build platform, to determine the bonding widths between stacked strands in fused-filament fabrication. The considered polymer melt has an extremely high viscosity, which dominates in its deformation. Mainly considering the viscous effect, we derive analytical expressions of the flat width, compressed depth, bonding width and cross-sectional profile of the filament in four special cases, which have different combinations of extrusion speed, print speed and nozzle height. We further validate the derived relations, using our experimental results on acrylonitrile butadiene styrene (ABS), as well as existing experimental and numerical results on ABS and polylactic acid (PLA). Compared with existing theoretical and numerical results, our derived analytic relations are simple, which need less calculations. They can be used to quickly predict the geometries of the deposited strands, including the bonding widths.

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Numerical simulations of the mesostructure formation in material extrusion additive manufacturing

Cited by 61 publications

References 48 publications

Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing

Numerical Simulation of a Core–Shell Polymer Strand in Material Extrusion Additive Manufacturing

An Overview of Additive Manufacturing Technologies—A Review to Technical Synthesis in Numerical Study of Selective Laser Melting

Bonding widths of Deposited Polymer Strands in Additive Manufacturing

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