Implicit Slicing for Functionally Tailored Additive Manufacturing

2016 ◽  
Author(s):  
John C. Steuben ◽  
Athanasios P. Iliopoulos ◽  
John G. Michopoulos
Keyword(s):  
Additive Manufacturing ◽  
Functional Performance ◽  
Three Dimensional ◽  
Computationally Efficient ◽  
Geometric Transformations ◽  
Crucial Component ◽  
Implicit Approach ◽  
G Code ◽  
Manufacturing Software ◽  
Future Work

One crucial component of the additive manufacturing software toolchain is a class of geometric algorithms known as “slicers.” The purpose of the slicer is to compute a parametric toolpath defined at the mesoscale and associated g-code commands, which direct an additive manufacturing system to produce a physical realization of a three-dimensional input model. Existing slicing algorithms operate by application of geometric transformations upon the input geometry in order to produce the toolpath. In this paper we introduce an implicit slicing algorithm that computes mesoscale toolpaths from the level sets of heuristics-based or physics-based fields defined over the input geometry. This enables computationally efficient slicing of arbitrarily complex geometries in a straight forward fashion. The calculation of component “infill” is explored, as a process control parameter, due to its strong influence on the produced component’s functional performance. Several examples of the application of the proposed implicit slicer are presented. It is demonstrated — via proper experimentation — that the implicit slicer can produce a mesoscale structure leading to objects of superior functional performance such as greatly increased stiffness and ultimate strength without an increase of mass. We conclude with remarks regarding the strengths of the implicit approach relative to existing explicit approaches, and discuss future work required in order to extend the methodology.

Design for additive manufacturing: a comprehensive review of the tendencies and limitations of methodologies

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Luis Lisandro Lopez Taborda ◽  
Heriberto Maury ◽  
Jovanny Pacheco
Keyword(s):  
Additive Manufacturing ◽  
Design Methodology ◽  
Functional Performance ◽  
Cost Evaluation ◽  
Product Management ◽  
Design For Additive Manufacturing ◽  
Content Type ◽  
Starting Point ◽  
The Subject ◽  
Future Work

Purpose There are many investigations in design methodologies, but there are also divergences and convergences as there are so many points of view. This study aims to evaluate to corroborate and deepen other researchers’ findings, dissipate divergences and provide directing to future work on the subject from a methodological and convergent perspective. Design/methodology/approach This study analyzes the previous reviews (about 15 reviews) and based on the consensus and the classifications provided by these authors, a significant sample of research is analyzed in the design for additive manufacturing (DFAM) theme (approximately 80 articles until June of 2017 and approximately 280–300 articles until February of 2019) through descriptive statistics, to corroborate and deepen the findings of other researchers. Findings Throughout this work, this paper found statistics indicating that the main areas studied are: multiple objective optimizations, execution of the design, general DFAM and DFAM for functional performance. Among the main conclusions: there is a lack of innovation in the products developed with the methodologies, there is a lack of exhaustivity in the methodologies, there are few efforts to include environmental aspects in the methodologies, many of the methods include economic and cost evaluation, but are not very explicit and broad (sustainability evaluation), it is necessary to consider a greater variety of functions, among other conclusions Originality/value The novelty in this study is the methodology. It is very objective, comprehensive and quantitative. The starting point is not the case studies nor the qualitative criteria, but the figures and quantities of methodologies. The main contribution of this review article is to guide future work on the subject from a methodological and convergent perspective and this article provides a broad database with articles containing information on many issues to make decisions: design methodology; optimization; processes, selection of parts and materials; cost and product management; mechanical, electrical and thermal properties; health and environmental impact, etc.

Functional Performance Tailoring of Additively Manufactured Components via Topology Optimization

2017 ◽  
Author(s):  
John C. Steuben ◽  
John G. Michopoulos ◽  
Athanasios P. Iliopoulos ◽  
Andrew J. Birnbaum
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
High Performance ◽  
Functional Performance ◽  
Underwater Vehicle ◽  
Length Scale ◽  
Hand Tool ◽  
Component Shape ◽  
Future Work ◽  
Am Processes

The freedom of design that is afforded by Additive Manufacturing (AM) processes opens exciting possibilities for the production of lightweight, high performance components and structures. Consequently, in recent years the development of software tools to enable engineering design methods that exploit the unique features of AM has become a subject of increased research interest. In this paper we explore the use of Topology Optimization (TO) algorithms to tailor component shape in order to achieve the intended functionality of additively manufactured components at the macro length scale. We present two case studies: the first concerns the hierarchical nesting of functions in a hand tool, while the second covers the development of a metamaterial component substructure for an Uninhabited Underwater Vehicle (UUV) hull. We offer conclusions regarding the usefulness of TO techniques for the design of AM components, and a summary of future work, which we feel is necessary to improve such methodologies.

Virtual Environments for Assessing and Rehabilitating Cognitive/Functional Performance A Review of Projects at the USC Integrated Media Systems Center

2001 ◽  
Vol 10 (4) ◽  
pp. 359-374 ◽  
Author(s):  
Albert A. Rizzo ◽  
J. Galen Buckwalter ◽  
Jocelyn S. McGee ◽  
Todd Bowerly ◽  
Cheryl van der Zaag ◽  
...  
Keyword(s):  
Virtual Environments ◽  
Functional Performance ◽  
Empirical Studies ◽  
Three Dimensional ◽  
Head Mounted Display ◽  
Wide Range ◽  
Visuospatial Skills ◽  
Media Systems ◽  
Integrated Media ◽  
Future Work

Virtual reality (VR) technology offers new options for the creation of sophisticated tools that could be applied in the areas of assessment and rehabilitation of cognitive and functional processes. VR systems allow for the precise presentation and control of dynamic, multisensory, three-dimensional (3-D) stimulus environments, as well as the recording of all behavioral responses that occur within them. Assessment and rehabilitation scenarios that would be difficult if not impossible to deliver using conventional neuropsychological methods are now being developed that take advantage of these VR assets. If empirical studies demonstrate effectiveness, virtual environments (VEs) could be of considerable value for better understanding, measuring, and treating persons with impairments due to traumatic brain injury, neurological disorders, and learning disabilities. This article describes the progress of a VR research program at the USC Integrated Media Systems Center and Information Sciences Institute that has developed and investigated the use of a series of VEs designed to target (i) molecular visuospatial skills using a 3-D, projection-based ImmersaDesk system, and (ii) attention (and soon memory and executive functioning) processes within ecologically valid functional scenarios utilizing a head-mounted display (HMD). Results from completed research, rationales and methodology of works in progress, and our plan for future work is presented. Our primary vision has been to develop VR systems that target cognitive processes and functional skills that are of relevance to a wide range of patient populations with central nervous system (CNS) dysfunction, as well as for the assessment of unimpaired performance. We have also sought to select cognitive/functional targets that intuitively appear well matched to the specific assets available with currently available VR technology.

scholarly journals 3D Puzzle in Cube Pattern for Anisotropic/Isotropic Mechanical Control of Structure Fabricated by Metal Additive Manufacturing

Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 959
Author(s):  
Naoko Ikeo ◽  
Hidetsugu Fukuda ◽  
Aira Matsugaki ◽  
Toru Inoue ◽  
Ai Serizawa ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Mechanical Performance ◽  
Functional Performance ◽  
Three Dimensional ◽  
Material Design ◽  
Metal Additive Manufacturing ◽  
Anisotropic Mechanical Properties ◽  
Innovative Material ◽  
Living Tissues ◽  
Metal Additive

Metal additive manufacturing is a powerful tool for providing the desired functional performance through a three-dimensional (3D) structural design. Among the material functions, anisotropic mechanical properties are indispensable for enabling the capabilities of structural materials for living tissues. For biomedical materials to replace bone function, it is necessary to provide an anisotropic mechanical property that mimics that of bones. For desired control of the mechanical performance of the materials, we propose a novel 3D puzzle structure with cube-shaped parts comprising 27 (3 × 3 × 3) unit compartments. We designed and fabricated a Co–Cr–Mo composite structure through spatial control of the positional arrangement of powder/solid parts using the laser powder bed fusion (L-PBF) method. The mechanical function of the fabricated structure can be predicted using the rule of mixtures based on the arrangement pattern of each part. The solid parts in the cubic structure were obtained by melting and solidifying the metal powder with a laser, while the powder parts were obtained through the remaining nonmelted powders inside the structure. This is the first report to achieve an innovative material design that can provide an anisotropic Young’s modulus by arranging the powder and solid parts using additive manufacturing technology.

scholarly journals MRI–Compatible Fluid-Powered Medical Devices

2013 ◽  
Vol 135 (06) ◽  
pp. S13-S16 ◽  
Author(s):  
Jun Ueda ◽  
David B. Comber ◽  
Jonathon Slightam ◽  
Melih Turkseven ◽  
Vito Gervasi ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Medical Devices ◽  
Imaging Techniques ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Recent Developments ◽  
Mri Environment ◽  
Magnetic Resonance Imaging Mri ◽  
End Use ◽  
Future Work

This article introduces recent developments and challenges related to magnetic resonance imaging (MRI)-compatible medical devices. Recent advances in fluid-powered medical devices are described, including a needle steering robot for neurosurgery and a haptic device for hemiplegia rehabilitation. Recent three-dimensional printing technologies for fabricating integrated fluid-powered robots are also reported. The use of additive manufacturing conjoined with modern digital imaging techniques allow for the customization of components, a trait that is generally needed in medical implants and devices. Furthermore, the materials that are available in additive processes allow for direct end-use production of customized components and devices. In addition, the polymer-based materials have an inherently low permeability, allowing for use in an MRI environment while not causing imaging interference. Presently, selective laser sintering (SLS), stereolithography, and extrusion processes illustrate and suggest that they offer the greatest promise in MRI compatible end-use components. Future work is aimed at using Additive Manufacturing (AM) to develop inherently safe, compact, MRI compatible medical devices.

scholarly journals Direct texturing for additive manufacturing: software support and build tests

2019 ◽  
Vol 26 (5) ◽  
pp. 881-894
Author(s):  
Antonio Armillotta
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Software Tool ◽  
Computational Procedure ◽  
Software Support ◽  
Content Type ◽  
Long Time ◽  
Manufacturing Software ◽  
Plastic Parts

Purpose This paper aims to investigate the feasibility of adding macro-textures to triangle meshes for additive manufacturing (AM) focusing on possible time and quality issues in both software processing and part fabrication. Design/methodology/approach A demonstrative software tool was developed to apply user-selected textures to existing meshes. The computational procedure is a three-dimensional extension of the solid texturing method used in computer graphics. The tool was tested for speed and quality of results, considering also the pre- and post-processing operations required. Some textured meshes were printed by different processes to test build speed and quality. Findings The tool can handle models with realistic complexity in acceptable computation times. Parts are built without difficulties or extra-costs achieving a good aesthetic yield of the texture. Research limitations/implications The tool cannot reproduce sample patterns but requires the development of a generation algorithm for different type of textures. Mesh processing operations may take a long time when very fine textures are added to large parts. Practical implications Direct texturing can help obtain parts with aesthetic or functional textures without the need for surface post-treatments, which can be especially difficult and expensive for plastic parts. Originality/value The proposed method improves the uniformity and consistency of textures compared to existing approaches, and can support future systematic studies on the detail resolution of AM processes.

Modeling and Fabrication of Heterogeneous Three-Dimensional Objects Based on Additive Manufacturing

2013 ◽  
Author(s):  
Pu Huang ◽  
Dongping Deng ◽  
Yong Chen
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Heterogeneous Materials ◽  
Test Cases ◽  
Heterogeneous Model ◽  
Three Dimensional Objects ◽  
Physical Experiments ◽  
Heterogeneous Objects ◽  
Heterogeneous Object Modeling ◽  
Future Work

Heterogeneous object modeling and fabrication has been studied in the past few decades. Recently the idea of digital materials has been demonstrated by using Additive Manufacturing (AM) processes. Our previous study illustrated that the mask-image-projection based Stereolithography (MIP-SL) process is promising in fabricating such heterogeneous objects. In the paper, we present an integrated framework for modeling and fabricating heterogenous objects based on the MIP-SL process. Our approach can achieve desired grading transmission between different materials in the object by considering the fabrication constraints of the MIP-SL process. The MIP-SL process planning of a heterogeneous model and the hardware setup for its fabrication are also presented. Test cases including physical experiments are performed to demonstrate the possibility of using heterogeneous materials to achieve desired physical properties. Future work on the design and fabrication of objects with heterogeneous materials is also discussed.

On Multiphysics Discrete Element Modeling of Powder-Based Additive Manufacturing Processes

2016 ◽  
Author(s):  
John C. Steuben ◽  
Athanasios P. Iliopoulos ◽  
John G. Michopoulos
Keyword(s):  
Additive Manufacturing ◽  
Discrete Element ◽  
Test Problems ◽  
Manufacturing Processes ◽  
Discrete Element Modeling ◽  
Metal Powders ◽  
Computationally Efficient ◽  
Residual Strains ◽  
Future Work ◽  
Am Processes

Physically accurate modeling of powder-based additive manufacturing (AM) processes can play an enabling role for both the certification and qualification as well as the functional tailoring of materials produced by these processes. In an effort to address these needs in a computationally efficient and physically realistic manner, this paper presents the initial efforts towards the development of a methodology for simulating polydisperse particle-based AM processes by the use of the Multiphysics Discrete Element Method (MDEM). We discuss the formulation of a DEM framework for addressing the unique multiphysics behavior of AM materials and processes. In particular, we focus on coupled thermo-mechanical effects that result in residual strains and deformation. The MDEM approach is demonstrated on several test problems involving laser sintering of metal powders. The paper concludes with a discussion on how this approach may be generalized to broader classes of AM systems, and details are given regarding future work that must be accomplished in order to further develop the present methodology.

Custom Presurgical Planning for Midfacial Reconstruction

2020 ◽  
Vol 36 (06) ◽  
pp. 696-702
Author(s):  
Nolan B. Seim ◽  
Enver Ozer ◽  
Sasha Valentin ◽  
Amit Agrawal ◽  
Mead VanPutten ◽  
...  
Keyword(s):  
Multidisciplinary Approach ◽  
Functional Performance ◽  
Three Dimensional ◽  
Free Tissue Transfer ◽  
Long Term Effects ◽  
Presurgical Planning ◽  
Dental Rehabilitation ◽  
Midface Reconstruction ◽  
Reconstructive Algorithm

AbstractResection and reconstruction of midface involve complex ablative and reconstructive tools in head and oncology and maxillofacial prosthodontics. This region is extraordinarily important for long-term aesthetic and functional performance. From a reconstructive standpoint, this region has always been known to present challenges to a reconstructive surgeon due to the complex three-dimensional anatomy, the variable defects created, combination of the medical and dental functionalities, and the distance from reliable donor vessels for free tissue transfer. Another challenge one faces is the unique features of each individual resection defect as well as individual patient factors making each preoperative planning session and reconstruction unique. Understanding the long-term effects on speech, swallowing, and vision, one should routinely utilize a multidisciplinary approach to resection and reconstruction, including head and neck reconstructive surgeons, prosthodontists, speech language pathologists, oculoplastic surgeons, dentists, and/or craniofacial teams as indicated and with each practice pattern. With this in mind, we present our planning and reconstructive algorithm in midface reconstruction, including a dedicated focus on dental rehabilitation via custom presurgical planning.

scholarly journals Phase-field modeling of grain evolutions in additive manufacturing from nucleation, growth, to coarsening

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Min Yang ◽  
Lu Wang ◽  
Wentao Yan
Keyword(s):  
Additive Manufacturing ◽  
Phase Field ◽  
Field Model ◽  
Three Dimensional ◽  
Phase Field Model ◽  
Nucleation Theory ◽  
Experimental Result ◽  
Classical Nucleation Theory ◽  
Validation Experiment ◽  
Powder Particles

AbstractA three-dimensional phase-field model is developed to simulate grain evolutions during powder-bed-fusion (PBF) additive manufacturing, while the physically-informed temperature profile is implemented from a thermal-fluid flow model. The phase-field model incorporates a nucleation model based on classical nucleation theory, as well as the initial grain structures of powder particles and substrate. The grain evolutions during the three-layer three-track PBF process are comprehensively reproduced, including grain nucleation and growth in molten pools, epitaxial growth from powder particles, substrate and previous tracks, grain re-melting and re-growth in overlapping zones, and grain coarsening in heat-affected zones. A validation experiment has been carried out, showing that the simulation results are consistent with the experimental results in the molten pool and grain morphologies. Furthermore, the grain refinement by adding nanoparticles is preliminarily reproduced and compared against the experimental result in literature.

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