DEM simulation of particles of complex shapes using the multisphere method: Application for additive manufacturing

Purpose Once an uneven substrate is aligned, traditional control theories and methods can be used on it, so aligning is of great significance for the development of wire and arc additive manufacturing (WAAM). This paper aims to propose a shape-driven control method for aligning a substrate with slopes to expand the application of WAAM. Design/methodology/approach A substrate with slopes must be aligned by depositing weld beads with slopes. First, considering the large height differences of slopes, multi-layer deposition is needed, and the number of layer of weld beads must be ascertained. Second, the change in the deposition rate is controlled as a ramp function to generate weld beads with slopes. Third, the variation of the deposition rate must be fine-tuned to compensate for the deviation between the actual and theoretical layer heights at the deposition of each layer. Finally, the parameters of the ramp functions at the deposition of each layer are determined through an optimization method. Findings First, to model the response function of layer height to deposition rate, the experiments are conducted with the deposition rate jumping from 4 to 8 mm/s and from 8 to 4 mm/s. When the deposition rate jumps from 4 to 8 mm/s and from 8 to 4 mm/s, the difference in the height of each layer decreases as the number of layer increases. Second, the variation of the deposition rate can be fine-tuned based on the deviation between the measured and theoretical layer heights because the variation of the deposition rate is proportional to the layer height when the initial and end deposition rates are near 4 or 8 mm/s, respectively. Third, the experimental results demonstrate that the proposed method is effective for single-layer aligning and aligning a substrate with one or more slopes. Originality/value The proposed method can expand the application of WAAM to an uneven substrate with slopes and lays the foundation for aligning tasks focused on uneven substrates with more complex shapes.

Download Full-text

Additive manufacturing of graded B4C-Al cermets with complex shapes

Materials & Design ◽

10.1016/j.matdes.2020.108516 ◽

2020 ◽

Vol 188 ◽

pp. 108516 ◽

Cited By ~ 2

Author(s):

Swetha Chandrasekaran ◽

Ryan Lu ◽

Richard Landingham ◽

James T. Cahill ◽

Luke Thornley ◽

...

Keyword(s):

Additive Manufacturing ◽

Complex Shapes

Download Full-text

Computational Foundations for Using Three Degrees of Freedom Build Platforms to Enable Supportless Extrusion-Based Additive Manufacturing

Volume 1: Additive Manufacturing; Manufacturing Equipment and Systems; Bio and Sustainable Manufacturing ◽

10.1115/msec2019-3024 ◽

2019 ◽

Cited By ~ 4

Author(s):

Prahar M. Bhatt ◽

Rishi K. Malhan ◽

Satyandra K. Gupta

Keyword(s):

Surface Roughness ◽

Additive Manufacturing ◽

Manufacturing Systems ◽

Degrees Of Freedom ◽

Support Structures ◽

Complex Shapes ◽

Build Time ◽

Time Accuracy ◽

Three Degrees Of Freedom

Abstract Extrusion-based additive manufacturing systems usually use three degrees of freedom extrusion tools to perform the deposition operation. This requires the use of support structures to deposit structures with overhang features. The use of support structures can be avoided by adding degrees of freedom to the build platform. The elimination of build structures can offer benefits in terms of reduction of build time and elimination of postprocessing costs. This paper demonstrates that the use of three degrees of freedom build platform enables printing of complex shapes without support structures. We present computational foundations for generating paths and trajectories for synchronizing the motion of three degrees of freedom build platforms and three degrees of freedom extrusion tools. We report results on six different test parts in terms of reduction in build time, accuracy, and surface roughness.

Download Full-text

Fractals and Additive Manufacturing

International Journal of Automation Technology ◽

10.20965/ijat.2016.p0222 ◽

2016 ◽

Vol 10 (2) ◽

pp. 222-230 ◽

Cited By ~ 9

Author(s):

A. M. M. Sharif Ullah ◽

◽

D. M. D’Addona ◽

Khalifa H. Harib ◽

Than Lin ◽

...

Keyword(s):

Additive Manufacturing ◽

Fractal Geometry ◽

Model Building ◽

Physical Models ◽

Virtual Model ◽

Building Capacity ◽

3D Cad ◽

Complex Shapes ◽

Design And Manufacturing ◽

Available Technology

Fractal geometry can create virtual models of complex shapes as CAD data, and from these additive manufacturing can directly create physical models. The virtual-model-building capacity of fractal geometry and the physical-model-building capacity of additive manufacturing can be integrated to deal with the design and manufacturing of complex shapes. This study deals with the manufacture of fractal shapes using commercially available additive manufacturing facilities and 3D CAD packages. Particular interest is paid to building physical models of an IFS-created fractal after remodeling it for manufacturing. This article introduces three remodeling methodologies based on binary-grid, convex/concave-hull, and line-model techniques. The measurements of the manufactured fractal shapes are also reported, and the degree of accuracy that can be achieved by the currently available technology is shown.

Download Full-text

Novel Designs of Turbine Blades for Additive Manufacturing

Volume 5C: Heat Transfer ◽

10.1115/gt2016-56084 ◽

2016 ◽

Cited By ~ 2

Author(s):

Liubov Magerramova ◽

Boris Vasilyev ◽

Vladimir Kinzburskiy

Keyword(s):

Additive Manufacturing ◽

Complex Geometry ◽

Turbine Blades ◽

Engine Performance ◽

Test Results ◽

Cooling Systems ◽

3D Tomography ◽

Low Pressure Turbine ◽

Complex Shapes ◽

Design And Manufacturing

Improving engine performance requires creating new materials and improving design and manufacturing. Additive Manufacturing (AM) is advancing rapidly and allows us to produce details of complex shapes that cannot be produced by traditional methods. The goal of this study was to demonstrate the possibility of using AM for the manufacture of turbine blades with a complex geometry, including those with advanced cooling systems, which cannot be manufactured by conventional methods. This paper presents the results of the design and calculations of high-pressure turbine (HPT) cooled blades, as well as a low-pressure turbine (LPT) uncooled blade that was designed using topology optimization (TO). Several blades were manufactured using AM. 3D tomography test results for those blades confirm the possibility of AM application in production of blades with complex geometry.

Download Full-text

Simulation of Micro/Nanopowder Mixing Characteristics for Dry Spray Additive Manufacturing of Li-Ion Battery Electrodes

Journal of Micro and Nano-Manufacturing ◽

10.1115/1.4037769 ◽

2017 ◽

Vol 5 (4) ◽

Cited By ~ 2

Author(s):

Brandon Ludwig ◽

Jin Liu ◽

Yangtao Liu ◽

Zhangfeng Zheng ◽

Yan Wang ◽

...

Keyword(s):

Additive Manufacturing ◽

Surface Energy ◽

Material Surface ◽

Powder Materials ◽

Li Ion Battery ◽

Dem Simulation ◽

Manufacturing Method ◽

Dry Electrode ◽

Mixing Characteristics ◽

Li Ion

A new dry spraying additive manufacturing method for Li-ion batteries has been developed to replace the conventional slurry-casting technique for manufacturing Li-ion battery electrodes. A dry spray manufacturing process can allow for the elimination of the time- and energy-intensive slurry drying process needed due to the use solvents to make the electrodes. Previous studies into the new manufacturing method have shown successful fabrication of electrodes which have strong electrochemical and mechanical performance. Li-ion battery electrodes typically consist of three basic materials: active material (AM), binder particle additives (BPA), and conductive particle additives (CPA). In this paper, a discrete element method (DEM) simulation was developed and used to study the mixing characteristics of dry electrode powder materials. Due to the size of the particles being in the submicron to micron size range, the mixing characteristics are heavily dependent on van der Waals adhesive forces between the particles. Therefore, the effect the Li-ion battery electrode material surface energy has on the mixing characteristics was studied. Contour plots based on the DEM simulation results where the surface energy components of selected material types are changed were used to predict the mixing characteristics of different particle systems. For the cases studied, it is found that experimental mixing results are representative of the results of the DEM simulations.

Download Full-text

Optimizing Cutting Planes for Advanced Joining and Additive Manufacturing

Volume 2: Advanced Manufacturing ◽

10.1115/imece2016-67495 ◽

2016 ◽

Cited By ~ 1

Author(s):

Brandon Massoni ◽

Matthew I. Campbell

Keyword(s):

Additive Manufacturing ◽

Cutting Planes ◽

Three Dimensional ◽

Optimization Method ◽

Main Body ◽

Optimal Separation ◽

Complex Shapes ◽

Definition Of ◽

The Individual ◽

Manufacturing Alternatives

While additive manufacturing allows more complex shapes than conventional manufacturing processes, there is a clear benefit in leveraging both new and old processes in the definition of new parts. For example, one could create complex part shapes where the main “body” is defined by extrusion and machining, while small protruding features are defined by additive manufacturing. This paper looks at how optimization and geometric reasoning can be combined to identify optimal separation planes within a complex three-dimensional shapes. These separations indicate the joining processes in reverse. The optimization method presents possible manufacturing alternatives to an engineering designer where optimality is defined as a minimization of cost. The process identifies the cutting planes as well as the combination of processes required to join the individual parts together. The paper presents several examples of complex shapes and describes how the optimization finds the optimal results.

Download Full-text

Additive Manufacturing of Functionally Graded Objects: A Review

Volume 1A: 36th Computers and Information in Engineering Conference ◽

10.1115/detc2016-60320 ◽

2016 ◽

Cited By ~ 4

Author(s):

Binbin Zhang ◽

Prakhar Jaiswal ◽

Rahul Rai ◽

Saigopal Nelaturi

Keyword(s):

Additive Manufacturing ◽

Functionally Graded ◽

Graded Materials ◽

Research Attention ◽

Complex Shapes ◽

Spatial Composition ◽

Planning Processes ◽

Key Aspects ◽

Modeling Representation ◽

Part Orientation

Functionally graded materials (FGM) have recently attracted a lot of research attention in the wake of the recent prominence of additive manufacturing (AM) technology. The continuously varying spatial composition profile of two or more materials affords FGM object to simultaneously possess ideal properties of multiple different materials. Additionally, emerging technologies in AM domain enables one to make complex shapes with customized multifunctional material properties in an additive fashion, where laying down successive layers of material creates an object. In this paper, we focus on providing an overview of research at the intersection of AM techniques and FGM objects. We specifically discuss the FGM modeling representation schemes and outline a classification system to classify existing FGM representation methods. We also highlight the key aspects such as the part orientation, slicing, and path planning processes that are essential for fabricating a quality FGM object through the use of multi-material AM techniques.

Download Full-text

Mechanical Properties of 3D Printed Biomimicked Composites

Volume 12: Materials: Genetics to Structures ◽

10.1115/imece2018-86309 ◽

2018 ◽

Author(s):

Seyed M. Allameh ◽

Roger Miller ◽

Hadi Allameh

Keyword(s):

Mechanical Properties ◽

Additive Manufacturing ◽

3D Printing ◽

Soft Materials ◽

Structural Composites ◽

Home Building ◽

Complex Shapes ◽

3D Printed ◽

Bend Tests ◽

Point Bend

Additive manufacturing technology has significantly matured over the last two decades. Recent progress in 3D printing has made it an attractive choice for fabricating complex shapes out of select materials possessing desirable properties at small and large scales. The application of biomimetics to the fabrication of structural composites has been shown to enhance their toughness and dynamic shear resistance. Building homes from bioinspired composites is possible if the process is automated. This can be achieved through additive manufacturing where layers of hard and soft materials can be deposited by 3D printing. This study examines mechanical properties of reinforced concrete fabricated by 3D printing. Preliminary results of 4-point bend tests are presented and the implications of 3D-printed home building on current conventional construction practices are discussed.

Download Full-text

Additive Manufacturing for Medical and Biomedical Applications: Advances and Challenges

Materials Science Forum ◽

10.4028/www.scientific.net/msf.783-786.1286 ◽

2014 ◽

Vol 783-786 ◽

pp. 1286-1291 ◽

Cited By ~ 8

Author(s):

Andrey Koptioug ◽

Lars Erik Rännar ◽

Mikael Bäckström ◽

Marie Cronskär

Keyword(s):

Electron Beam ◽

Additive Manufacturing ◽

Electron Beam Melting ◽

Biomedical Applications ◽

Rapid Development ◽

Industrial Applications ◽

Post Processing ◽

New Materials ◽

Industrial Manufacturing ◽

Complex Shapes

Additive Manufacturing (AM) has solidly established itself not only in rapid prototyping but also in industrial manufacturing. Its success is mainly determined by a possibility of manufacturing components with extremely complex shapes with minimal material waste. Rapid development of AM technologies includes processes using unique new materials, which in some cases is very hard or impossible to process any other way. Along with traditional industrial applications AM methods are becoming quite successful in biomedical applications, in particular in implant and special tools manufacturing. Here the capacity of AM technologies in producing components with complex geometric shapes is often brought to extreme. Certain issues today are preventing the AM methods taking its deserved place in medical and biomedical applications. Present work reports on the advances in further developing of AM technology, as well as in related post-processing, necessary to address the challenges presented by biomedical applications. Particular examples used are from Electron Beam Melting (EBM), one of the methods from the AM family.

Download Full-text