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5 pages, 214 KiB

Open AccessEditorial

Design for Additive Manufacturing: Methods and Tools

by Marco Mandolini, Patrick Pradel and Paolo Cicconi

Appl. Sci. 2022, 12(13), 6548; https://doi.org/10.3390/app12136548 - 28 Jun 2022

Cited by 5 | Viewed by 2564

Abstract

Additive Manufacturing (AM), one of the nine enabling technologies of Industry 4.0, is experiencing rapid growth [...] Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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Research

Jump to: Editorial, Review

18 pages, 7467 KiB

Open AccessArticle

Guidelines for Topology Optimization as Concept Design Tool and Their Application for the Mechanical Design of the Inner Frame to Support an Ancient Bronze Statue

by Abas Ahmad, Michele Bici and Francesca Campana

Appl. Sci. 2021, 11(17), 7834; https://doi.org/10.3390/app11177834 - 25 Aug 2021

Cited by 6 | Viewed by 2451

Abstract

For the past few decades, topology optimization (TO) has been used as a structural design optimization tool. With the passage of time, this kind of usage of TO has been extended to many application fields and branches, thanks to a better understanding of [...] Read more.

For the past few decades, topology optimization (TO) has been used as a structural design optimization tool. With the passage of time, this kind of usage of TO has been extended to many application fields and branches, thanks to a better understanding of how manufacturing constraints can achieve a practical design solution. In addition, the advent of additive manufacturing and its subsequent advancements have further increased the applications of TO, raising the chance of competitive manufacturing. Design for additive manufacturing has also promoted the adoption of TO as a concept design tool of structural components. Nevertheless, the most frequent applications are related to lightweight design with or without design for assembly. A general approach to integrate TO in concept designs is still missing. This paper aims to close this gap by proposing guidelines to translate design requirements into TO inputs and to include topology and structural concerns at the early stage of design activity. Guidelines have been applied for the concept design of an inner supporting frame of an ancient bronze statue, with several constraints related to different general design requirements, i.e., lightweight design, minimum displacement, and protection of the statue’s structural weak zones to preserve its structural integrity. Starting from the critical analysis of the list of requirements, a set of concepts is defined through the application of TO with different set-ups (loads, boundary conditions, design and non-design space) and ranked by the main requirements. Finally, a validation of the proposed approach is discussed comparing the achieved results with the ones carried out through a standard iterative concept design. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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15 pages, 3612 KiB

Open AccessArticle

Development Workflow for Manifolds and Fluid Components Based on Laser Powder Bed Fusion

by Nicolas Rolinck, Matthias Schmitt, Matthias Schneck, Georg Schlick and Johannes Schilp

Appl. Sci. 2021, 11(16), 7335; https://doi.org/10.3390/app11167335 - 9 Aug 2021

Cited by 7 | Viewed by 2395

Abstract

Through its unique characteristics, additive manufacturing yields great potential for designing fluid components with increased performance characteristics. These potentials in advanced design, functional structure, and manufacturing are not easily realized. Therefore, the present study proposes a holistic development methodology for fluid components with [...] Read more.

Through its unique characteristics, additive manufacturing yields great potential for designing fluid components with increased performance characteristics. These potentials in advanced design, functional structure, and manufacturing are not easily realized. Therefore, the present study proposes a holistic development methodology for fluid components with a specific focus on hydraulic manifolds. The methodology aims to lead the designer from the specification of the task, through a step-by-step embodied design, to a technical and economic evaluation of the optimized, first-time manufactured part. A case study applies the proposed methodology to a part of a rail-vehicle braking application. Through its application, a significant reduction in weight, size, as well as significant contributions to the company’s AM strategy can be assigned to the part. At the same time, increased direct manufacturing costs are identified. Based on the increased performance characteristics of the resulting design and the holistic foundation of the subsequent economic decisions, a satisfying efficiency can be allocated to the proposed methodology. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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15 pages, 513 KiB

Open AccessArticle

Enhancing Design for Additive Manufacturing Workflow: Optimization, Design and Simulation Tools

by Nicolas Alberto Sbrugnera Sotomayor, Fabrizia Caiazzo and Vittorio Alfieri

Appl. Sci. 2021, 11(14), 6628; https://doi.org/10.3390/app11146628 - 19 Jul 2021

Cited by 20 | Viewed by 5068

Abstract

In the last few decades, complex light-weight designs have been successfully produced via additive manufacturing (AM), launching a new era in the thinking–design process. In addition, current software platforms provide design tools combined with multi-scale simulations to exploit all the technology benefits. However, [...] Read more.

In the last few decades, complex light-weight designs have been successfully produced via additive manufacturing (AM), launching a new era in the thinking–design process. In addition, current software platforms provide design tools combined with multi-scale simulations to exploit all the technology benefits. However, the literature highlights that several stages must be considered in the design for additive manufacturing (DfAM) process, and therefore, performing holistic guided-design frameworks become crucial to efficiently manage the process. In this frame, this paper aims at providing the main optimization, design, and simulation tools to minimize the number of design evaluations generated through the different workflow assessments. Furthermore, DfAM phases are described focusing on the implementation of design optimization strategies as topology optimization, lattice infill optimization, and generative design in earlier phases to maximize AM capabilities. In conclusion, the current challenges for the implementation of the workflow are hence described. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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19 pages, 6177 KiB

Open AccessArticle

A Finite Element Method to Predict the Mechanical Behavior of a Pre-Structured Material Manufactured by Fused Filament Fabrication in 3D Printing

by Marouene Zouaoui, Julien Gardan, Pascal Lafon, Ali Makke, Carl Labergere and Naman Recho

Appl. Sci. 2021, 11(11), 5075; https://doi.org/10.3390/app11115075 - 30 May 2021

Cited by 17 | Viewed by 4701

Abstract

In this paper, a numerical method is proposed to simulate the mechanical behavior of a new polymeric pre-structured material manufactured by fused filament fabrication (FFF), where the filaments are oriented along the principal stress directions. The model implements optimized filament orientations, obtained from [...] Read more.

In this paper, a numerical method is proposed to simulate the mechanical behavior of a new polymeric pre-structured material manufactured by fused filament fabrication (FFF), where the filaments are oriented along the principal stress directions. The model implements optimized filament orientations, obtained from the G code by assigning materials references in mesh elements. The Gauss points are later configured with the physical behavior while considering a homogeneous solid structure. The objective of this study is to identify the elastoplastic behavior. Therefore, tensile tests were conducted with different filament orientations. The results show that using appropriate material constants is efficient in describing the built anisotropy and incorporating the air gap volume fraction. The suggested method is proved very efficient in implementing multiplex G code orientations. The elastic behavior of the pre-structured material is quasi-isotropic. However, the anisotropy was observed at the yield point and the ultimate stress. Using the Hill criterion coupled with an experimental tabular law of the plastic flow turns out to be suitable for predicting the response of various specimens. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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14 pages, 3804 KiB

Open AccessFeature PaperArticle

An Optimization Workflow in Design for Additive Manufacturing

by Stefano Rosso, Federico Uriati, Luca Grigolato, Roberto Meneghello, Gianmaria Concheri and Gianpaolo Savio

Appl. Sci. 2021, 11(6), 2572; https://doi.org/10.3390/app11062572 - 13 Mar 2021

Cited by 23 | Viewed by 4883

Abstract

Additive Manufacturing (AM) brought a revolution in parts design and production. It enables the possibility to obtain objects with complex geometries and to exploit structural optimization algorithms. Nevertheless, AM is far from being a mature technology and advances are still needed from different [...] Read more.

Additive Manufacturing (AM) brought a revolution in parts design and production. It enables the possibility to obtain objects with complex geometries and to exploit structural optimization algorithms. Nevertheless, AM is far from being a mature technology and advances are still needed from different perspectives. Among these, the literature highlights the need of improving the frameworks that describe the design process and taking full advantage of the possibilities offered by AM. This work aims to propose a workflow for AM guiding the designer during the embodiment design phase, from the engineering requirements to the production of the final part. The main aspects are the optimization of the dimensions and the topology of the parts, to take into consideration functional and manufacturing requirements, and to validate the geometric model by computer-aided engineering software. Moreover, a case study dealing with the redesign of a piston rod is presented, in which the proposed workflow is adopted. Results show the effectiveness of the workflow when applied to cases in which structural optimization could bring an advantage in the design of a part and the pros and cons of the choices made during the design phases were highlighted. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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12 pages, 2290 KiB

Open AccessFeature PaperArticle

Data-Efficient Neural Network for Track Profile Modelling in Cold Spray Additive Manufacturing

by Daiki Ikeuchi, Alejandro Vargas-Uscategui, Xiaofeng Wu and Peter C. King

Appl. Sci. 2021, 11(4), 1654; https://doi.org/10.3390/app11041654 - 12 Feb 2021

Cited by 23 | Viewed by 4831

Abstract

Cold spray is emerging as an additive manufacturing technique, particularly advantageous when high production rate and large build sizes are in demand. To further accelerate technology’s industrial maturity, the problem of geometric control must be improved, and a neural network model has emerged [...] Read more.

Cold spray is emerging as an additive manufacturing technique, particularly advantageous when high production rate and large build sizes are in demand. To further accelerate technology’s industrial maturity, the problem of geometric control must be improved, and a neural network model has emerged to predict additively manufactured geometry. However, limited data on the effect of deposition conditions on geometry growth is often problematic. Therefore, this study presents data-efficient neural network modelling of a single-track profile in cold spray additive manufacturing. Two modelling techniques harnessing prior knowledge or existing model were proposed, and both were found to be effective in achieving the data-efficient development of a neural network model. We also showed that the proposed data-efficient neural network model provided better predictive performance than the previously proposed Gaussian function model and purely data-driven neural network. The results indicate that a neural network model can outperform a widely used mathematical model with data-efficient modelling techniques and be better suited to improving geometric control in cold spray additive manufacturing. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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13 pages, 2082 KiB

Open AccessArticle

Design for Additive Manufacturing: Tool Review and a Case Study

by Daniel Moreno Nieto and Daniel Moreno Sánchez

Appl. Sci. 2021, 11(4), 1571; https://doi.org/10.3390/app11041571 - 9 Feb 2021

Cited by 35 | Viewed by 6569

Abstract

This paper aims to collect in a structured manner different computer-aided engineering (CAE) tools especially developed for additive manufacturing (AM) that maximize the capabilities of this technology regarding product development. The flexibility of the AM process allows the manufacture of highly complex shapes [...] Read more.

This paper aims to collect in a structured manner different computer-aided engineering (CAE) tools especially developed for additive manufacturing (AM) that maximize the capabilities of this technology regarding product development. The flexibility of the AM process allows the manufacture of highly complex shapes that are not possible to produce by any other existing technology. This fact enables the use of some existing design tools like topology optimization that has already existed for decades and is used in limited cases, together with other novel developments like lattice design tools. These two technologies or design approaches demand a highly flexible manufacturing system to be applied and could not be used before, due to the conventional industrial process limitations. In this paper, these technologies will be described and combined together with other generic or specific design tools, introducing the study case of an additive manufactured mechanical design of a bicycle stem. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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15 pages, 12101 KiB

Open AccessArticle

Leveraging the Advantages of Additive Manufacturing to Produce Advanced Hybrid Composite Structures for Marine Energy Systems

by Paul Murdy, Jack Dolson, David Miller, Scott Hughes and Ryan Beach

Appl. Sci. 2021, 11(3), 1336; https://doi.org/10.3390/app11031336 - 2 Feb 2021

Cited by 13 | Viewed by 3530

Abstract

Many marine energy systems designers and developers are beginning to implement composite materials into the load-bearing structures of their devices, but traditional mold-making costs for composite prototyping are disproportionately high and lead times can be long. Furthermore, established molding techniques for marine energy [...] Read more.

Many marine energy systems designers and developers are beginning to implement composite materials into the load-bearing structures of their devices, but traditional mold-making costs for composite prototyping are disproportionately high and lead times can be long. Furthermore, established molding techniques for marine energy structures generally require many manufacturing steps, such as secondary bonding and tooling. This research explores the possibilities of additively manufactured internal composite molds and how they can be used to reduce costs and lead times through novel design features and processes for marine energy composite structures. In this approach, not only can the composite mold be additively manufactured but it can also serve as part of the final load-bearing structure. We developed a conceptual design and implemented it to produce a reduced-scale additive/composite tidal turbine blade section to fully demonstrate the manufacturing possibilities. The manufacturing was successful and identified several critical features that could expedite the tidal turbine blade manufacturing process, such as single-piece construction, an integrated shear web, and embedded root fasteners. The hands-on manufacturing also helped identify key areas for continued research to allow for efficient, durable, and low-cost additive/composite-manufactured structures for future marine energy systems. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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21 pages, 1778 KiB

Open AccessArticle

A Systematic Approach for Evaluating the Adoption of Additive Manufacturing in the Product Design Process

by Roberto Raffaeli, Jacopo Lettori, Juliana Schmidt, Margherita Peruzzini and Marcello Pellicciari

Appl. Sci. 2021, 11(3), 1210; https://doi.org/10.3390/app11031210 - 28 Jan 2021

Cited by 17 | Viewed by 3575

Abstract

Additive Manufacturing (AM) technologies have expanded the possibility of producing unconventional geometries, also increasing the freedom of design. However, in the designer’s everyday work, the decision regarding the adoption of AM for the production of a component is not straightforward. In fact, it [...] Read more.

Additive Manufacturing (AM) technologies have expanded the possibility of producing unconventional geometries, also increasing the freedom of design. However, in the designer’s everyday work, the decision regarding the adoption of AM for the production of a component is not straightforward. In fact, it is necessary to process much information regarding multiple fields to exploit the maximum potential of additive production. For example, there is a need to evaluate the properties of the printable materials, their compatibility with the specific application, redesign shapes accordingly to AM limits, and conceive unique and complex products. Additionally, procurement and logistics evaluations, as well as overall costs possibly extending to the entire life cycle, are necessary to come to a decision for a new and radical solution. In this context, this paper investigates the complex set of information involved in this process. Indeed, it proposes a framework to support and guide a designer by means of a structured and algorithmic procedure to evaluate the opportunity for the adoption of AM and come to an optimal design. A case study related to an ultralight aircraft part is reported to demonstrate the proposed decision process. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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17 pages, 8778 KiB

Open AccessArticle

Smooth Design of 3D Self-Supporting Topologies Using Additive Manufacturing Filter and SEMDOT

by Yun-Fei Fu, Kazem Ghabraie, Bernard Rolfe, Yanan Wang and Louis N. S. Chiu

Appl. Sci. 2021, 11(1), 238; https://doi.org/10.3390/app11010238 - 29 Dec 2020

Cited by 13 | Viewed by 2562

Abstract

The smooth design of self-supporting topologies has attracted great attention in the design for additive manufacturing (DfAM) field as it cannot only enhance the manufacturability of optimized designs but can obtain light-weight designs that satisfy specific performance requirements. This paper integrates Langelaar’s AM [...] Read more.

The smooth design of self-supporting topologies has attracted great attention in the design for additive manufacturing (DfAM) field as it cannot only enhance the manufacturability of optimized designs but can obtain light-weight designs that satisfy specific performance requirements. This paper integrates Langelaar’s AM filter into the Smooth-Edged Material Distribution for Optimizing Topology (SEMDOT) algorithm—a new element-based topology optimization method capable of forming smooth boundaries—to obtain print-ready designs without introducing post-processing methods for smoothing boundaries before fabrication and adding extra support structures during fabrication. The effects of different build orientations and critical overhang angles on self-supporting topologies are demonstrated by solving several compliance minimization (stiffness maximization) problems. In addition, a typical compliant mechanism design problem—the force inverter design—is solved to further demonstrate the effectiveness of the combination between SEMDOT and Langelaar’s AM filter. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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14 pages, 27970 KiB

Open AccessArticle

Novel Resistive Sensor Design Utilizing the Geometric Freedom of Additive Manufacturing

by Hagen Watschke, Marijn Goutier, Julius Heubach, Thomas Vietor, Kay Leichsenring and Markus Böl

Appl. Sci. 2021, 11(1), 113; https://doi.org/10.3390/app11010113 - 24 Dec 2020

Cited by 18 | Viewed by 3499

Abstract

Direct additive manufacturing (AM) of sensors has in recent years become possible, but still remains a largely unexplored area. This work proposes a novel resistive sensor design that utilizes the geometric freedom offered by AM, especially by material extrusion, to enable a customizable [...] Read more.

Direct additive manufacturing (AM) of sensors has in recent years become possible, but still remains a largely unexplored area. This work proposes a novel resistive sensor design that utilizes the geometric freedom offered by AM, especially by material extrusion, to enable a customizable and amplified response to force and deformation. This is achieved by using a multi-material design made of an elastomer and an electrically conductive polymer that enables a physical shortening of the conductive path under compressive load through a specific definition of shape. A number of different variants of this novel sensor design are tested, measuring their mechanical and electrical behavior under compression. The results of these tests confirm a strong resistive response to mechanical loading. Furthermore, the results provide insight into the influencing factors of the design, i.e., the gap size between the conductive pathing and the stiffness of the sense element support structure are found to be primary influencing factors governing sensor behavior. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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19 pages, 9971 KiB

Open AccessFeature PaperArticle

Enhancing Structural Performance of Short Fiber Reinforced Objects through Customized Tool-Path

by Jaeyoon Kim and Bruce S. Kang

Appl. Sci. 2020, 10(22), 8168; https://doi.org/10.3390/app10228168 - 18 Nov 2020

Cited by 13 | Viewed by 3313

Abstract

Fused deposition modeling (FDM) is one of the most common additive manufacturing (AM) technologies for thermoplastic materials. With the development of carbon fiber-reinforced polymer (CFRP) filament for FDM, AM parts with improved strength and functionality can be realized. CFRP is anisotropic material and [...] Read more.

Fused deposition modeling (FDM) is one of the most common additive manufacturing (AM) technologies for thermoplastic materials. With the development of carbon fiber-reinforced polymer (CFRP) filament for FDM, AM parts with improved strength and functionality can be realized. CFRP is anisotropic material and its mechanical properties have been well studied, however, AM printing strategy for CFRP parts has not been developed. This paper proposes a systematic optimization of the FDM 3D printing process for CFRP. Starting with standard coupon specimen tests to obtain mechanical properties of CFRP, finite element analyses (FEA) were conducted to find principal directions of the AM part and utilized to determine fiber orientations. A specific tool-path algorithm has been developed to distribute fibers with the desired orientations. To predict/assess the mechanical behavior of the AM part, the 3D printing process was simulated to obtain the anisotropic mechanical behavior induced by the customized tool-path printing. Bolt hole plate and spur gear were selected as case studies. FE simulations and associated experiments were conducted to assess their performance. CFRP parts printed by the optimized tool-path shows about 8% higher stiffness than those printed at regular infill patterns. In summary, assisted by FEA, a customized 3D printing tool-path for CFRP has been developed with case studies to verify the proposed AM design optimization methodology for FDM. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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13 pages, 4689 KiB

Open AccessArticle

Integration of Topology Optimisation and Design Variants Selection for Additive Manufacturing-Based Systematic Product Redesign

by Enrico Dalpadulo, Francesco Gherardini, Fabio Pini and Francesco Leali

Appl. Sci. 2020, 10(21), 7841; https://doi.org/10.3390/app10217841 - 5 Nov 2020

Cited by 17 | Viewed by 3625

Abstract

The development of additive manufacturing allows the transformation of technological processes and the redesign of products. Among the most used methods to support additive manufacturing, the design can be optimised through the integration of topology optimisation techniques, allowing for creating complex shapes. However, [...] Read more.

The development of additive manufacturing allows the transformation of technological processes and the redesign of products. Among the most used methods to support additive manufacturing, the design can be optimised through the integration of topology optimisation techniques, allowing for creating complex shapes. However, there are critical issues (i.e., definition of product and process parameters, selection of redesign variants, optimised designs interpretation, file exchange and data management, etc.) in identifying the most appropriate process and set-ups, as well as in selecting the best variant on a functional and morphological level. Therefore, to fully exploit the technological potentials and overcome the drawbacks, this paper proposes a systematic redesign approach based on additive manufacturing technologies that integrate topology optimisation and a tool for selecting design variants based on the optimisation of both product and process features. The method leads to the objective selection of the best redesigned configuration in accordance with the key performance indicators (KPIs) (i.e., functional and production requirements). As a case study, the redesign of a medical assistive device is proposed, previously developed in fused filament fabrication and now optimised for being 3D printed with selective laser melting. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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18 pages, 6219 KiB

Open AccessArticle

Design and Fabrication of Complex-Shaped Ceramic Bone Implants via 3D Printing Based on Laser Stereolithography

by Alexander Safonov, Evgenii Maltsev, Svyatoslav Chugunov, Andrey Tikhonov, Stepan Konev, Stanislav Evlashin, Dmitry Popov, Alexander Pasko and Iskander Akhatov

Appl. Sci. 2020, 10(20), 7138; https://doi.org/10.3390/app10207138 - 14 Oct 2020

Cited by 21 | Viewed by 6577

Abstract

3D printing allows the fabrication of ceramic implants, making a personalized approach to patients’ treatment a reality. In this work, we have tested the applicability of the Function Representation (FRep) method for geometric simulation of implants with complex cellular microstructure. For this study, [...] Read more.

3D printing allows the fabrication of ceramic implants, making a personalized approach to patients’ treatment a reality. In this work, we have tested the applicability of the Function Representation (FRep) method for geometric simulation of implants with complex cellular microstructure. For this study, we have built several parametric 3D models of 4 mm diameter cylindrical bone implant specimens of four different types of cellular structure. The 9.5 mm long implants are designed to fill hole defects in the trabecular bone. Specimens of designed ceramic implants were fabricated at a Ceramaker 900 stereolithographic 3D printer, using a commercial 3D Mix alumina (Al₂O₃) ceramic paste. Then, a single-axis compression test was performed on fabricated specimens. According to the test results, the maximum load for tested specimens constituted from 93.0 to 817.5 N, depending on the size of the unit cell and the thickness of the ribs. This demonstrates the possibility of fabricating implants for a wide range of loads, making the choice of the right structure for each patient much easier. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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14 pages, 1490 KiB

Open AccessArticle

Additively Manufactured Parametric Universal Clip-System: An Open Source Approach for Aiding Personal Exposure Measurement in the Breathing Zone

by Kirsi Kukko, Jan Sher Akmal, Anneli Kangas, Mika Salmi, Roy Björkstrand, Anna-Kaisa Viitanen, Jouni Partanen and Joshua M. Pearce

Appl. Sci. 2020, 10(19), 6671; https://doi.org/10.3390/app10196671 - 24 Sep 2020

Cited by 9 | Viewed by 3292

Abstract

Design for additive manufacturing is adopted to help solve problems inherent to attaching active personal sampler systems to workers for monitoring their breathing zone. A novel and parametric 3D printable clip system was designed with an open source Computer-aided design (CAD) system and [...] Read more.

Design for additive manufacturing is adopted to help solve problems inherent to attaching active personal sampler systems to workers for monitoring their breathing zone. A novel and parametric 3D printable clip system was designed with an open source Computer-aided design (CAD) system and was additively manufactured. The concept was first tested with a simple clip design, and when it was found to be functional, the ability of the innovative and open source design to be extended to other applications was demonstrated by designing another tooling system. The clip system was tested for mechanical stress test to establish a minimum lifetime of 5000 openings, a cleaning test, and a supply chain test. The designs were also tested three times in field conditions. The design cost and functionalities of the clip system were compared to commercial systems. This study presents an innovative custom-designed clip system that can aid in attaching different tools for personal exposure measurement to a worker’s harness without hindering the operation of the worker. The customizable clip system opens new possibilities for occupational health professionals since the basic design can be altered to hold different kinds of samplers and tools. The solution is shared using an open source methodology. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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Review

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26 pages, 7588 KiB

Open AccessReview

Geometrical Degrees of Freedom for Cellular Structures Generation: A New Classification Paradigm

by Ken M. Nsiempba, Marc Wang and Mihaela Vlasea

Appl. Sci. 2021, 11(9), 3845; https://doi.org/10.3390/app11093845 - 23 Apr 2021

Cited by 12 | Viewed by 3602

Abstract

Cellular structures (CSs) have been used extensively in recent years, as they offer a unique range of design freedoms. They can be deployed to create parts that can be lightweight by introducing controlled porous features, while still retaining or improving their mechanical, thermal, [...] Read more.

Cellular structures (CSs) have been used extensively in recent years, as they offer a unique range of design freedoms. They can be deployed to create parts that can be lightweight by introducing controlled porous features, while still retaining or improving their mechanical, thermal, or even vibrational properties. Recent advancements in additive manufacturing (AM) technologies have helped to increase the feasibility and adoption of cellular structures. The layer-by-layer manufacturing approach offered by AM is ideal for fabricating CSs, with the cost of such parts being largely independent of complexity. There is a growing body of literature concerning CSs made via AM; this presents an opportunity to review the state-of-the-art in this domain and to showcase opportunities in design and manufacturing. This review will propose a novel way of classifying cellular structures by isolating their Geometrical Degrees of Freedom (GDoFs) and will explore the recent innovations in additively manufactured CSs. Based on the present work, the design inputs that are common in CSs generation will be highlighted. Furthermore, the work explores examples of how design inputs have been used to drive the design domain through various case studies. Finally, the review will highlight the manufacturability limitations of CSs in AM. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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64 pages, 5165 KiB

Open AccessReview

Topology Optimisation in Structural Steel Design for Additive Manufacturing

by Tiago P. Ribeiro, Luís F. A. Bernardo and Jorge M. A. Andrade

Appl. Sci. 2021, 11(5), 2112; https://doi.org/10.3390/app11052112 - 27 Feb 2021

Cited by 47 | Viewed by 13630

Abstract

Topology Optimisation is a broad concept deemed to encapsulate different processes for computationally determining structural materials optimal layouts. Among such techniques, Discrete Optimisation has a consistent record in Civil and Structural Engineering. In contrast, the Optimisation of Continua recently emerged as a critical [...] Read more.

Topology Optimisation is a broad concept deemed to encapsulate different processes for computationally determining structural materials optimal layouts. Among such techniques, Discrete Optimisation has a consistent record in Civil and Structural Engineering. In contrast, the Optimisation of Continua recently emerged as a critical asset for fostering the employment of Additive Manufacturing, as one can observe in several other industrial fields. With the purpose of filling the need for a systematic review both on the Topology Optimisation recent applications in structural steel design and on its emerging advances that can be brought from other industrial fields, this article critically analyses scientific publications from the year 2015 to 2020. Over six hundred documents, including Research, Review and Conference articles, added to Research Projects and Patents, attained from different sources were found significant after eligibility verifications and therefore, herein depicted. The discussion focused on Topology Optimisation recent approaches, methods, and fields of application and deepened the analysis of structural steel design and design for Additive Manufacturing. Significant findings can be found in summarising the state-of-the-art in profuse tables, identifying the recent developments and research trends, as well as discussing the path for disseminating Topology Optimisation in steel construction. Full article

(This article belongs to the Special Issue Design for Additive Manufacturing: Methods and Tools)

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