International Journal of Rapid Manufacturing (14 papers in press)
Additive Manufacturing of H13 Tooling Element with Conformal Cooling Channel Using MIG Cladding
by Fisseha Legesse, Sajan Kapil, Hari Vithasth, K.P. Karunakaran
Abstract: Hybrid Layered Manufacturing (HLM) is a synergic integration of additive and subtractive manufacturing processes. It takes the positive aspects of both the processes such as accuracy through subtractive and reduction of material through additive. In this work, The Metal Inert Gas (MIG) cladding has been used for addition and CNC milling machining is used for subtraction. The process parameters for MIG cladding of H-13 tool steel material was investigated using Taguchi DOE method. The effect of different process parameters such as current, torch speed and standoff distance, on weld bead width, height and penetration have been studied using ANOVA. This paper describes the methodology of analyzing and manufacturing of a die element using H13 tool steel material with a proper conformal cooling channel and in-situ preheating process using an induction heating system.
Keywords: Hybrid Layered Manufacturing; Baffle & Bubbler cooling; MIG Cladding; In-situ preheating.
Multi Objective Optimization of Fused Deposition Modelling process parameters using RSM and fuzzy logic for build time and support material
by Manu Srivastava
Abstract: Additive Manufacturing (AM) is around three-decade old technology and enables quick transition from concept to physical models in a matter of hours. Fused deposition modelling (FDM) is a promising and robust AM technique with proven ability to build prototypes of complex and intricate shapes using reasonable time and cost. Optimization of FDM process requires optimization of various qualitative and quantitative responses. This work presents multi-objective FDM optimization using RSM embedded fuzzy logic analysis. Six process parameters and two responses are considered for the current experimentation on Fortus 250mc modeller based on FDM technology.
Keywords: Additive manufacturing; Fused deposition modelling; Build time; Support material Volume; Response surface methodology; Fuzzy logic.
Digital Design Integrity for Additive Manufacturing: Examining reliability issues in the digital preproduction process
by Steven L. Brown, Harry A. Pierson
Abstract: Despite a literature base stretching over three decades, the digital pre-production process for additive manufacturing continues to lack integration and robustness. Current best practice relies on operators to identify potential issues to prevent scrap and rework. While most academic research focuses on systematic tessellation approximation errors, this paper offers a detailed investigation of nonsystematic translation errors and their root causes. All stages of the digital pre-production process (tessellation, slicing, and tool path generation) were found to be equally vulnerable, and no common commercial software tool was found to be superior in its ability to prevent translation errors. Given the improbability of completely eliminating digital translation problems under the current paradigm, this paper proposes an alternative with new feedback loops to ensure digital design integrity.
Keywords: additive manufacturing; 3D printing; additive manufacturing quality; meshing; slicing; toolpath generation; CAD; tessellation; translation verification.
Numerical and experimental analysis of product development by composite metal foil manufacturing
by Javaid Butt, Habtom Mebrahtu, Hassan Shirvani
Abstract: The paper presents a new additive manufacturing process for the production of high quality metal parts using metal foil and is termed as Composite Metal Foil Manufacturing. It is a blend of Laminated Object Manufacturing and soldering/brazing strategies. A calculated model of a machine in view of the new process has been outlined and its parts accepted for usefulness either by experimentation or recreations. The advantages of the process include simplicity and flexibility in operation combined with strong and high quality resulting metal parts. The product development has two stages -- the principles of Laminated Object Manufacturing for cutting and stacking of foils and brazing for joining. A 300W MIYACHI fibre laser is used for cutting of metal foils. The foils are coated with a special brazing paste, 80% zinc and 20% aluminium by weight, with the use of 710 applicator. The thickness is measured at every instance with two Microtrak 3 TGS on either side of the build platform. The cutting process produce heat that melts the brazing paste at the edges of the foils and allow them to stay in alignment. It makes moving the part onto the heating plates easy for final joining. The heated plates apply heat and pressure to ensure proper bonding of the foils. In this paper, the process is described as a whole with detailed explanation of every component and their functionality. Furthermore, some results of investigations on the sub-processes; laser cutting, final joining and transient thermal analysis are shown.
Keywords: additive manufacturing; laminated object manufacturing; metal parts; metal foil; laser cutting; brazing; CFD analysis.
Thingiverse: Review and Analysis of Available Files
by Felix Baumann, Dieter Roller
Abstract: This paper aims to present an overview of the thingiverse digital model repository
and provides an analysis of a subset of randomly selected models of this site. To
carry out this study, literature research was conducted to identify relevant works
that focus on this platform. Based on existing research, a subset of available
models is acquired and analysed utilising existing open source software. Focusing
on the geometrical details of the acquired models, an analysis is performed.
Furthermore, statistical data such as download and view counters of these models,
in association with an analysis of the utilised licences is collected. For the literature
review on this platform, 25 existing works were identified and are presented in this
article. From the 10000 randomly selected ThingIDs, 3528 Things were existent
and files could be acquired. 3078 files are of either ASCII STL format (∼66.7 %)
or binary STL format (∼33.3 %), which are used for further analysis. The average
download and view count for these models is 269.2 and 1004.7, respectively. Most
metrics calculated, e.g., average volume, size or facet count, are dominated by
less than 20 % of all the analysed models. One source of digital models for
additive manufacturing or 3D printing are online repositories. In such repositories,
users can deposit their designs and models for others to use. Usage includes the
download, fabrication and re-mixing of existing models. For this, knowledge of
licensing and quality of the deposited files is important. To better assess the
suitability of such a repository, a meta-review is beneficial as it guides the reader
towards different aspects of this platform that are already researched. This paper
suggest that the licence of choice for almost half of the acquired models from the
thingiverse repository is a Creative Commons - Attribution - Share Alike licence.
It is shown that about 80 % of all models downloaded have a view (82.1 %) and
download (81.9 %) count that is lower than the average. The removal rate of
objects is less than 1 % over a period of seven months. For the literature review
on the platform, 25 contributions were identified that cover predominantly this
online platform/community thingiverse.
Keywords: Online Model Repository; Design Community; Licencing; Review;rnFile Analysis; Online Service; 3D Printing.
Design and development of customized split insole using additive manufacturing technique
by Sivakumar Ganesan, Rajesh Ranganathan
Abstract: Medical researchers are seeking innovative manufacturing methods to produce health care products alike; prosthetics, implants, diabetic foot care product, etc., faster and more accurately. This research focuses on exploring the current technical challenges and provides a unique solution through additive manufacturing method in the development of customized split insole. Custom foot insole is developed by considering the essential anatomical study on bio-mechanics, anthropometric data of the human foot, gait analysis and plantar pressure. A new product custom body fitted product was developed considering the various mechanical and human parameters and the results are discussed with the possible improvements that the developed insoles have provided. The developed insole increases contact area and redistributes average peak plantar pressure, reduces at Zones 2 and 3 by 27.78 % and 76.92% respectively. This research work provides the methodology to manufacture a customized split insole using an additive manufacturing technique.
Keywords: Anthropometry; foot biomechanics; plantar pressure and 3D Printing /additive manufacturing.
Special Issue on: Additive Manufacturing in Architecture
The Current State of Autography
by Kostas Grigoriadis
Abstract: As the practice of using notations to translate from two to three-dimensions is gradually being replaced by the direct, autographic relaying of building information digitally, the separation between designing and building is diminishing. Key to lessening further this division are heterogeneous materials, the imminent use of which can instigate the gradual superseding of building components and effectively tectonic construction. Pre-empting their anticipated widespread application, a main point syntax is presented of the expected changes that will occur in architecture as a result. Following this, a novel design method of using particle system elements to simulate the fusion of materials is deployed in the redesign of a building facade element through a multi-material. The ensuing focus is the fabrication of the element, which is performed by converting material data from the CFD program into a 3D-printable format. The current technical limitations of architectural autography are discussed through this workflow.
Keywords: autography; allography; architecture; digital design; multi-materials; functionally graded materials; particle system elements; cfd; rapid manufacturing; 3d printing; design theory.
In and Out of Control: Latent Opportunities within an Additive Manufacturing Process
by James Kerestes, Alayna Davidson
Abstract: Technology can become an active participant in the design process when users refrain from dictating how a tool should operate and perform. When digital and physical mediums are given participatory roles or authorship in the production of objects, the accepted conventions and typologies of design can be challenged and pushed beyond what is conceived to be possible and plausible. The research described in this article will explore the latent capabilities found within the equipment and materials utilized throughout the additive manufacturing process, and will examine their potential to incite form generation, material behaviour and fabrication. The focus will be on production methodologies that utilize material extrusion for the fabrication of physical objects. A series of production trials will explore and expand the origin of tectonic aesthetics relative to construction means and methods.
Keywords: Tool autopsy; computation; behavioral logic; idiosyncrasies; emergence; post-digital; robotics; additive manufacturing; material; machine latency.
Mesh Optimization for Spatial Wireframe Robotic 3D Printing
by Lei Yu, Dan Luo
Abstract: Most of the polygon meshing system and related algorithm are developed for geometrical optimization with rarely any practical consideration such as material performance and fabrication process. This paper intends to propose a different approach for mesh optimization that took practical elements such as material quality, fabrication sequence, and technical restriction into the consideration, developing a novel meshing algorithm. Through our novel nonlinear optimization process, a data intensive smart polygon mesh network system is generated that are optimized for a highly efficient construction process in coordination with a robotic FDM 3D printing system. The mesh network developed from such process and algorithm is structurally rational, cost efficient with far less construction time
Keywords: Mesh Optimization; FDM; Robotic Fabrication; 3D Printing Framework; Spatial Extrusion; Digital Computation; Digital Fabrication; Rapid Prototyping.
Design Workflow for Additive Manufacturing: A Comparative Study
by Vishu Bhooshan, Henry David Louth, Shajay Bhooshan, Patrik Schumacher
Abstract: Contemporary design for additive manufacture (AM) encounters a
multitude of variables including multiple disciplines, technological disparities,
and rigid and linear workflows. This paper presents a novel design workflow
to facilitate collaboration, and development of design geometry that is enriched
with manufacturing related information. The paper highlights adaptability of
the proposed workflow to additive manufacturing via case studies. lastly, it
also outlines the benefits of implementing fabrication-aware geometry, early
prototyping and validation methods as well as as extending the collaboration
period between collaborators in a multi-author design project.
Keywords: design workflow; project delivery; collaborative design; interactive
design; pipeline; design for manufacturing; fabrication-aware design; feedback,
parametric design; data-flow; growth; space-filling curves; packing; simulation,
topology optimization; differential geometry; developable surface; digital
reconstruction; constraint solving.
Seeking congruency in digital optimization and constructability in fabric formed ice shells utilizing bending active frames
by Lancelot Coar, Michael S. Cox, Sigrid Adriaenssens
Abstract: Fabric formed structures are widely used to produce structural forms through the use of a temporary rigid framing to support a flexible membrane as formwork. Recent research has sought to introduce flexible support systems for fabric formwork so that they may participate with the parametric behaviour of fabric, while providing useful constraints for design. In the project presented here, a bending active frame is used to create a fabric formed ice shell using this approach. A focus is placed on the use of ice as a temporary structural material that allows for iterative accumulation of mass during construction, as well as an analogous material for speculating about the use of other more permanent liquid-to-solid materials (like concrete). This project presents novel construction methods seeking to establish a meaningful link between digital optimization design techniques and the often incongruent realities that must be confronted to build such a structure.
Keywords: fabric formwork; ice structures; bending active; principal stress lines; digital optimization; construction techniques; shell structures.
by Panagiotis Michalatos, Andrew Payne
Abstract: With the advent of various additive manufacturing techniques, the creation of materials that are characterized by finely engineered porosity patterns becomes feasible. In this paper, we focus on the design workflows that could open these increasingly smaller scales to design exploration.
A flexible and interactive method to design porosity patterns should give designers the ability to control the porosity gradient (i.e. the ratio of solid to void at different locations in space), pore radii, cell topology, directionality (i.e. material or void continuity along certain spatial directions), and shape including variations in thickness, curvature and texture. In this paper, we present a method for combining volumetric texture coordinates with halftoning typographic techniques to enable an arbitrary flow of a micro-pattern defined by the potential fields of the texture coordinates. We call this method modulated pattern binarization.
Using this approach, we can leverage and even extend existing techniques developed for 2D surface reparameterization, image analysis and typography. In addition, the modulated pattern binarization process, unlike lattice-based methods, separates the pattern from the map; giving designers the ability to control the directionality of the pattern separately from its density and topology. This method is also computationally efficient, making it easy for designers to define patterns and pattern maps at interactive frame rates.
Furthermore, we examine a set of methods which can be used to analyze the geometric properties of both the pattern cell and its mapping. We conclude by discussing some of the possible techniques available for materializing porous structures using additive manufacturing (AM).
Keywords: cellular solid; porous materials; volumetric modeling; voxel representation; additive manufacturing; computer aided modeling (CAD).
Fabrication-aware structural optimisation of lattice additive-manufactured with robot-arm
by Kam-Ming Mark Tam, Daniel J.M. Marshall, Mitchell Gu, Justin A. Lavallee, Caitlin T. Mueller
Abstract: Architectural structures that achieve high strength and stiffness performance with intelligent, but intricate geometry may now be materialisable through the use of novel additive manufacturing (AM) techniques that inform and enable structurally driven form generation. However, conventional layer-based AM produces parts with inconsistent material properties, which reduce the structural strength of the printed object and limit the end-use application of AM. Expanding on emerging robotics-enabled AM techniques addressing this limitation, this paper contributes a new method for the design and fabrication of structurally optimised lattices. These lattices are morphed in 3D to maximize their structural stiffness-to-weight ratio while respecting fabrication constraints imposed by the robotic printing process. The digitally generated geometries are algorithmically converted into tool paths for PLA plastic extrusion with a custom-built end effector mounted on an industrial robot arm. Thermal imaging is used to calibrate the printing process, and a novel joint detail is developed to increase the reliability and load-transfer capabilities of the print. The efficacy of the printed structures are validated through a series of comparative structural load tests. Together, the computational design, fabrication, and load testing methodologies presented here show promise for architecture-scale AM that combines structurally driven geometry with complexity-agnostic materialization in new and exciting ways.
Keywords: Cellular material; lattice; additive manufacturing; fused deposition modelling; robotics; octet lattice truss; conformal lattice; 3-D truss; 3-D printed joints; bonding strength; structural load testing.
POLYBRICK 3.0 : Live Signatures Through DNA Hydrogels and Digital Ceramics
by David Rosenwasser, Shogo Hamada, Dan Luo, Jenny Sabin
Abstract: This article reflects upon new questions of material compatibility through integrating advanced processes of additive manufacturing in ceramics with cutting-edge research in DNA hydrogel development. The work engages advances in material science, three-dimensional (3D) printing, micro-scale mold making, DNA hydrogels, and material practices derived from crafts, and computational design disciplines. Polybrick 3.0 : Live Signatures Through DNA Hydrogels and Digital Ceramics outlines the use of micro scale three dimensional printing technologies for the digital fabrication and production of nonstandard and inscribed ceramic block components. 3D printed ceramic blocks are differentiated via the first architectural component glazed with DNA hydrogel and impregnated with a living signature. Three-dimensional modeling softwares enable precise 3D print resolution, which allows for an iterative feedback loop to be generated based on material constraints as well as performance assessments. Using modified digital fabrication machines, advanced ceramic clay bodies, and high resolution mold-making processes, our research utilizes 3D printing technology available on the consumer market to develop micro-scale forms with customizable wells to produce recognizable signatures imbedded with multiple layers of decodable intelligence prescribed through DNA coding. Operating at a scale that earlier 3D printing technology could not maneuver within, we developed a system of 3D printing molds to cast clay bodies. Eventually, this clay body was 3D printed to the same effect. We have designed a system that allows for 3D printed parts to exist at a micro-scale in the form of an architectural component and glaze mold, therefore allowing for the opportunistic deposition of DNA intelligence.
Keywords: digital ceramics; DNA hydrogels; live matter; PolyBrick; digital fabrication; SLA 3D printing; active matter; programmable matter; architectural science; matter design computation; generative architecture; bio-active materials.