scholarly journals Numerical simulation and experimental calibration of additive manufacturing by blown powder technology. Part I: thermal analysis

2017 ◽  
Vol 23 (2) ◽  
pp. 448-463 ◽  
Author(s):  
Michele Chiumenti ◽  
Xin Lin ◽  
Miguel Cervera ◽  
Wei Lei ◽  
Yuxiang Zheng ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Additive Manufacturing ◽  
Numerical Model ◽  
High Energy ◽  
Metal Deposition ◽  
Numerical Control ◽  
Experimental Calibration ◽  
Standard Format ◽  
Content Type ◽  
Scanning Pattern

Purpose This paper aims to address the numerical simulation of additive manufacturing (AM) processes. The numerical results are compared with the experimental campaign carried out at State Key Laboratory of Solidification Processing laboratories, where a laser solid forming machine, also referred to as laser engineered net shaping, is used to fabricate metal parts directly from computer-aided design models. Ti-6Al-4V metal powder is injected into the molten pool created by a focused, high-energy laser beam and a layer of added material is sinterized according to the laser scanning pattern specified by the user. Design/methodology/approach The numerical model adopts an apropos finite element (FE) activation technology, which reproduces the same scanning pattern set for the numerical control system of the AM machine. This consists of a complex sequence of polylines, used to define the contour of the component, and hatches patterns to fill the inner section. The full sequence is given through the common layer interface format, a standard format for different manufacturing processes such as rapid prototyping, shape metal deposition or machining processes, among others. The result is a layer-by-layer metal deposition which can be used to build-up complex structures for components such as turbine blades, aircraft stiffeners, cooling systems or medical implants, among others. Findings Ad hoc FE framework for the numerical simulation of the AM process by metal deposition is introduced. Description of the calibration procedure adopted is presented. Originality/value The objectives of this paper are twofold: firstly, this work is intended to calibrate the software for the numerical simulation of the AM process, to achieve high accuracy. Secondly, the sensitivity of the numerical model to the process parameters and modeling data is analyzed.

scholarly journals Thermal analysis of Wire Arc Additive Manufacturing process

2021 ◽  
Author(s):  
Mohamed Belhadj ◽  
Sana Werda ◽  
Asma Belhadj ◽  
Robin Kromer ◽  
Philippe Darnis
Keyword(s):  
Additive Manufacturing ◽  
Numerical Model ◽  
Heat Source ◽  
Manufacturing Process ◽  
High Energy ◽  
Metal Deposition ◽  
Innovative Technology ◽  
Thermal Cycles ◽  
Predictive Tool ◽  
Wire Arc Additive Manufacturing

Wire arc additive manufacturing process (WAAM) is an innovative technology that offers freedom in terms of designing functional parts, due to its ability to manufacture large and complex workpieces with a high rate of deposition. This technology is a metal AM process using an electric arc heat source. The parts manufactured are affected by thermal residual stresses due to high-energy input between wire and workpiece despite numerous advantages with this technology. It could cause severe deformation and change the global mechanical response. A 3D transient thermal model was created to evaluate the thermal gradients and fields during metal deposition. The material used in this study is a steel alloy (S355JR-AR). This numerical model takes into account the heat dissipation through the external environment and the heat loss through the cooling system under the base plate. Birth-element activation strategy was used to generate warm solid part following the movement of the heat source. The metal deposition is defined with constant welding speed. Goldak model was used to simulate the heat source in order to have a realistic heat flow distribution. Results were in concordance for thermal cycles at different points comparing with experimental results issued from bibliography in terms of: (1) Temperature maximum, (2) Thermal cycles and (3) Cooling gradient phase. This study enabled to check the numerical model and used as a predictive tool

Optimal space filling for additive manufacturing

2016 ◽  
Vol 22 (4) ◽  
pp. 660-675 ◽  
Author(s):  
Sajan Kapil ◽  
Prathamesh Joshi ◽  
Hari Vithasth Yagani ◽  
Dhirendra Rana ◽  
Pravin Milind Kulkarni ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Layered Manufacturing ◽  
Closed Curve ◽  
Numerical Control ◽  
Surface Finishing ◽  
Content Type ◽  
Single Pass ◽  
Connected Area ◽  
Area Filling

Purpose In additive manufacturing (AM) process, the physical properties of the products made by fractal toolpaths are better as compared to those made by conventional toolpaths. Also, it is desirable to minimize the number of tool retractions. The purpose of this study is to describe three different methods to generate fractal-based computer numerical control (CNC) toolpath for area filling of a closed curve with minimum or zero tool retractions. Design/methodology/approach This work describes three different methods to generate fractal-based CNC toolpath for area filling of a closed curve with minimum or zero tool retractions. In the first method, a large fractal square is placed over the outer boundary and then rest of the unwanted curve is trimmed out. To reduce the number of retractions, ends of the trimmed toolpath are connected in such a way that overlapping within the existing toolpath is avoided. In the second method, the trimming of the fractal is similar to the first method but the ends of trimmed toolpath are connected such that the overlapping is found at the boundaries only. The toolpath in the third method is a combination of fractal and zigzag curves. This toolpath is capable of filling a given connected area in a single pass without any tool retraction and toolpath overlap within a tolerance value equal to stepover of the toolpath. Findings The generated toolpath has several applications in AM and constant Z-height surface finishing. Experiments have been performed to verify the toolpath by depositing material by hybrid layered manufacturing process. Research limitations/implications Third toolpath method is suitable for the hybrid layered manufacturing process only because the toolpath overlapping tolerance may not be enough for other AM processes. Originality/value Development of a CNC toolpath for AM specifically hybrid layered manufacturing which can completely fill any arbitrary connected area in single pass while maintaining a constant stepover.

Rethinking reverse logistics: role of additive manufacturing technology in metal remanufacturing

2019 ◽  
Vol 31 (1) ◽  
pp. 124-144 ◽  
Author(s):  
Danielle Strong ◽  
Michael Kay ◽  
Thomas Wakefield ◽  
Issariya Sirichakwal ◽  
Brett Conner ◽  
...  
Keyword(s):  
Supply Chain ◽  
Additive Manufacturing ◽  
Facility Location ◽  
Reverse Logistics ◽  
Small And Medium Enterprises ◽  
Real Data ◽  
Cnc Machining ◽  
Numerical Control ◽  
Content Type ◽  
The Usa

Purpose Although the adoption of metal additive manufacturing (AM) for production has continuously grown, in-house access to production grade metal AM systems for small and medium enterprises (SMEs) is a major challenge due to costs of acquiring metal AM systems, specifically powder bed fusion AM. On the other hand, AM technology in directed energy deposition (DED) has been evolving in both: processing capabilities and adaptable configuration for integration within existing traditional machines that are available in most SME manufacturing facilities, e.g. computer numerical control (CNC) machining centers. Integrating DED with conventional processes such as machining and grinding into Hybrid AM is well suited for remanufacturing of metal parts. The paper aims to discuss these issues. Design/methodology/approach Classical facility location models are employed to understand the effects of SMEs adopting DED systems to offer remanufacturing services. This study identifies strategically located counties in the USA to advance hybrid AM for reverse logistics using North American Industry Classification System (NAICS) data on geographical data, demand, fixed and transportation costs. A case study is also implemented to explore its implications on remanufacturing of high-value parts on the reverse logistics supply chain using an aerospace part and NAICS data on aircraft maintenance, repair and overhaul facilities. Findings The results identify the candidate counties, their allocations, allocated demand and total costs. Offering AM remanufacturing services to traditional manufacturers decreases costs for SMEs in the supply chain by minimizing expensive new part replacement. The hubs also benefit from hybrid AM to repair their own parts and tools. Originality/value This research provides a unique analysis on reverse logistics through hybrid AM focused on remanufacturing rather than manufacturing. Facility location using real data is used to obtain results and offers insights into integrating AM for often overlooked aspect of remanufacturing. The study shows that SMEs can participate in the evolving AM economy through remanufacturing services using significantly lower investment costs.

scholarly journals Simplified numerical model for the laser metal deposition additive manufacturing process

2017 ◽  
Vol 29 (2) ◽  
pp. 022304 ◽  
Author(s):  
Patrice Peyre ◽  
Morgan Dal ◽  
Sébastien Pouzet ◽  
Olivier Castelnau
Keyword(s):  
Additive Manufacturing ◽  
Numerical Model ◽  
Manufacturing Process ◽  
Metal Deposition ◽  
Laser Metal Deposition

Temperature distribution simulations during electron beam freeform fabrication process based on the fully threaded tree

2019 ◽  
Vol 25 (6) ◽  
pp. 989-997
Author(s):  
Yajun Yin ◽  
Wei Duan ◽  
Kai Wu ◽  
Yangdong Li ◽  
Jianxin Zhou ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Temperature Field ◽  
Electron Beam ◽  
Additive Manufacturing ◽  
Temperature Distribution ◽  
Design Methodology ◽  
Content Type ◽  
Freeform Fabrication ◽  
Simulation Based ◽  
Simulation Results

Purpose The purpose of this study is to simulate the temperature distribution during an electron beam freeform fabrication (EBF3) process based on a fully threaded tree (FTT) technique in various scales and to analyze the temperature variation with time in different regions of the part. Design/methodology/approach This study presented a revised model for the temperature simulation in the EBF3 process. The FTT technique was then adopted as an adaptive grid strategy in the simulation. Based on the simulation results, an analysis regarding the temperature distribution of a circular deposit and substrate was performed. Findings The FTT technique was successfully adopted in the simulation of the temperature field during the EBF3 process. The temperature bands and oscillating temperature curves appeared in the deposit and substrate. Originality/value The FTT technique was introduced into the numerical simulation of an additive manufacturing process. The efficiency of the process was improved, and the FTT technique was convenient for the 3D simulations and multi-pass deposits.

Biomass pyrolysis modeling of systems at laboratory scale with experimental validation

2018 ◽  
Vol 28 (2) ◽  
pp. 413-438 ◽  
Author(s):  
Stefano Cordiner ◽  
Alessandro Manni ◽  
Vincenzo Mulone ◽  
Vittorio Rocco
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Fast Pyrolysis ◽  
Experimental System ◽  
High Energy ◽  
Numerical Results ◽  
Small Scale ◽  
Content Type ◽  
Slow Pyrolysis ◽  
Bio Oil

Purpose Thermochemical conversion processes are one of the possible solutions for the flexible production of electric and thermal power from biomass. The pyrolysis degradation process presents, among the others, the interesting features of biofuels and high energy density bio-oil production potential high conversion rate. In this paper, numerical results of a slow batch and continuous fast pyrolyzers, are presented, aiming at validating both a tridimensional computational fluid dynamics-discrete element method (CFD–DEM) and a monodimensional distributed activation energy model (DAEM) represents with data collected in dedicated experiments. The purpose of this paper is then to provide reliable models for industrial scale-up and direct design purposes. Design/methodology/approach The slow pyrolysis experimental system, a batch of small-scale constant-pressure bomb for allothermic conversion processes, is presented. A DEM numerical model has been implemented by means of a modified OpenFOAM solver. The fast pyrolysis experimental system and a lab scale screw reactor designed for biomass fast pyrolysis conversion are also presented along with a 1D numerical model to represent its operation. The model which is developed for continuous stationary feeding conditions and based on a four-parallel reaction chemical framework is presented in detail. Findings The slow pyrolysis numerical results are compared with experimental data in terms of both gaseous species production and reduction of the bed height showing good predictive capabilities. Fast pyrolysis numerical results have been compared to the experimental data obtained from the fast pyrolysis process of spruce wood pellet. The comparison shows that the chemical reaction modeling based on a Gaussian DAEM is capable of giving results in very good agreement with the bio-oil yield evaluated experimentally. Originality/value As general results of the proposed activities, a mixed experimental and numerical approach has demonstrated a very good potential in developing design tools for pyrolysis development.

Comparing environmental impacts of additive manufacturing vs traditional machining via life-cycle assessment

2015 ◽  
Vol 21 (1) ◽  
pp. 14-33 ◽  
Author(s):  
Jeremy Faludi ◽  
Cindy Bayley ◽  
Suraj Bhogal ◽  
Myles Iribarne
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Additive Manufacturing ◽  
Environmental Impacts ◽  
Surface Finish ◽  
Numerical Control ◽  
Cutting Fluid ◽  
Content Type ◽  
Electricity Use

Purpose – The purpose of this study is to compare the environmental impacts of two additive manufacturing machines to a traditional computer numerical control (CNC) milling machine to determine which method is the most sustainable. Design/methodology/approach – A life-cycle assessment (LCA) was performed, comparing a Haas VF0 CNC mill to two methods of additive manufacturing: a Dimension 1200BST FDM and an Objet Connex 350 “inkjet”/“polyjet”. The LCA’s functional unit was the manufacturing of two specific parts in acrylonitrile butadiene styrene (ABS) plastic or similar polymer, as required by the machines. The scope was cradle to grave, including embodied impacts, transportation, energy used during manufacturing, energy used while idling and in standby, material used in final parts, waste material generated, cutting fluid for CNC, and disposal. Several scenarios were considered, all scored using the ReCiPe Endpoint H and IMPACT 2002+ methodologies. Findings – Results showed that the sustainability of additive manufacturing vs CNC machining depends primarily on the per cent utilization of each machine. Higher utilization both reduces idling energy use and amortizes the embodied impacts of each machine. For both three-dimensional (3D) printers, electricity use is always the dominant impact, but for CNC at maximum utilization, material waste became dominant, and cutting fluid was roughly on par with electricity use. At both high and low utilization, the fused deposition modeling (FDM) machine had the lowest ecological impacts per part. The inkjet machine sometimes performed better and sometimes worse than CNC, depending on idle time/energy and on process parameters. Research limitations/implications – The study only compared additive manufacturing in plastic, and did not include other additive manufacturing technologies, such as selective laser sintering or stereolithography. It also does not include post-processing that might bring the surface finish of FDM parts up to the quality of inkjet or CNC parts. Practical implications – Designers and engineers seeking to minimize the environmental impacts of their prototypes should share high-utilization machines, and are advised to use FDM machines over CNC mills or polyjet machines if they provide sufficient quality of surface finish. Originality/value – This is the first paper quantitatively comparing the environmental impacts of additive manufacturing with traditional machining. It also provides a more comprehensive measurement of environmental impacts than most studies of either milling or additive manufacturing alone – it includes not merely CO2 emissions or waste but also acidification, eutrophication, human toxicity, ecotoxicity and other impact categories. Designers, engineers and job shop managers may use the results to guide sourcing or purchasing decisions related to rapid prototyping.

Local cathodic protection design based on numerical simulation

2015 ◽  
Vol 62 (6) ◽  
pp. 407-415 ◽  
Author(s):  
Gan Cui ◽  
Zili Li ◽  
Lingyu Zhao ◽  
Xu Wei
Keyword(s):  
Numerical Simulation ◽  
Cathodic Protection ◽  
Real Life ◽  
High Energy ◽  
Shielding Effect ◽  
Content Type ◽  
Gas Stations ◽  
Protection Technology ◽  
Protection Potential ◽  
The Mathematical Model

Purpose – The purpose of this investigation was to study these problems and design regional cathodic protection, using numerical simulation. Regional cathodic protection technology is immature at home and abroad. This is reflected in the fact that in gas stations, there are many underground pipelines, which can lead to serious interference and shielding phenomena, and there are many grounding networks that can cause substantial loss of the cathodic protection current. Design/methodology/approach – Based on the above, in this article, first of all, the mathematical model of the buried pipeline cathodic protection potential distribution was established and the control equations solved using the boundary element method. Second, the cathodic shielding effect in pipeline concentration areas, the effect of instrument equipment grounding systems on cathodic protection and the influence of DC stray current on the interference of pipeline corrosion were studied separately using BEASY software. Finally, the BEASY software was used for a regional cathodic protection design for a real gas station. Findings – It was concluded that impressed current used in combination with sacrificial anodes for regional cathodic protection design is often the most economic and effective approach. However, the output current of the auxiliary anode is large with high energy consumption. In consequence, it may be recommended that the station pipelines should be laid on the ground, rather than under it. Originality/value – It is considered that the results can guide regional cathodic protection design for real-life installations very well.

Foam additive manufacturing technology: main characteristics and experiments for hull mold manufacturing

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Elodie Paquet ◽  
Alain Bernard ◽  
Benoit Furet ◽  
Sébastien Garnier ◽  
Sébastien Le Loch
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Manufacturing Process ◽  
Manufacturing Industry ◽  
Pressure Head ◽  
Manufacturing Technology ◽  
Cnc Machining ◽  
Numerical Control ◽  
Content Type ◽  
Additive Manufacturing Technology

Purpose The purpose of this paper is to present a novel methodology to produce a large boat hull with a foam additive manufacturing (FAM) process. To respond to shipping market needs, this new process is being developed. FAM technology is a conventional three-dimensional (3D) printing process whereby layers are deposited onto a high-pressure head mounted on a six-axis robotic arm. Traditionally, molds and masters are made with computer numerical control (CNC) machining or finished by hand. Handcrafting the molds is obviously time-consuming and labor-intensive, but even CNC machining can be challenging for parts with complex geometries and tight deadlines. Design/methodology/approach The proposed FAM technology focuses on the masters and molds, that are directly produced by 3D printing. This paper describes an additive manufacturing technology through which the operator can create a large part and its tools using the capacities of this new FAM technology. Findings The study shows a comparison carried out between the traditional manufacturing process and the additive manufacturing process, which is illustrated through an industrial case of application in the manufacturing industry. This work details the application of FAM technology to fabricate a 2.5 m boat hull mold and the results show the time and cost savings of FAM in the fabrication of large molds. Originality/value Finally, the advantages and drawbacks of the FAM technology are then discussed and novel features such as monitoring system and control to improve the accuracy of partly printed are highlighted.

scholarly journals CFD flow analysis in the centrifugal vortex pump

2014 ◽  
Vol 24 (3) ◽  
pp. 545-562 ◽  
Author(s):  
Tihomir Mihalić ◽  
Zvonimir Guzović ◽  
Andrej Predin
Keyword(s):  
Numerical Model ◽  
Turbulence Model ◽  
Control Volume ◽  
Flow Analysis ◽  
Turbulence Models ◽  
Numerical Control ◽  
Computational Time ◽  
Back Side ◽  
Centrifugal Pumps ◽  
Content Type

Purpose – Aging of the oil wells leads to a decrease in reservoir pressure and also to an increase in the water, gas and abrasive particles content. Therefore, there is a need for the oil pumps exploitation characteristics improvements. This paper aims to generate a valuable numerical model which will provide a useful tool to study various cases. Design/methodology/approach – Computational fluid dynamics (CFD) analysis of the generation of so-called coherent structures of eddies and turbulence in the peripheral area of the vortex rotor mounted at the back side of centrifugal rotor was undertaken. After detailed analysis of the influence of the used turbulence models on the results, a hybrid turbulent model Detached Eddies Simulation (DES) was chosen as the most suitable. Findings – Numerical control volume method with unsteady solver and DES turbulence model was proven to be valuable tool for flow analysis in the centrifugal pumps. Having in mind that DES turbulence model consumes much less computational time than large eddies turbulence model, this is a very useful fact that resulted from this research. Practical implications – The proven numerical model is robust and reliable enough to become a standard method in simulating flow and other physical phenomena occurring in centrifugal pumps and similar turbo machines. This makes it possible to easily research different factors that influence their performances. Originality/value – Comprehensive experimental and CFD study was performed which made it possible to conduct detailed validation and verification of described CFD model.

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