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Environmental and technical evaluation of additive manufacturing: Enabling process chain perspective by energy value stream mapping

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Procedia CIRP 2022年 105卷 440-445页

作者： Mathias Wiese Christopher Rogall Nadja Henningsen Christoph Herrmann Sebastian Thiede Polymer Additive Manufacturing Center AUDI AG Auto-Union-Straße 1 Ingolstadt 85045 Germany Chair of Sustainable Manufacturing and Life Cycle Engineering Institute of Machine Tools and Production Technology Technische Universität Braunschweig Langer Kamp 19b Braunschweig 38106 Germany Fraunhofer Institute for Surface Engineering and Thin Films (IST) Bienroder Weg 54 E Braunschweig 38108 Germany Manufacturing Systems Faculty of Engineering Technology Department of Design Production & Management University of Twente De Horst 2 Building 20 Enschede 7522 LW The Netherlands

Additive manufacturing (AM) currently evolves from a prototyping process to an alternative manufacturing process for end-use parts, advancing into fabrication of low to medium product volumes. Moreover, increasing awareness of environmental impacts of manufacturing lead to the necessity of holistic evaluation among traditional evaluation criteria in the technical and economic domains. However, existing evaluation approaches seldom consider a complete AM process chain and are lacking a production-oriented notation which enables comparability across technologies and support in identification of improvement potentials on technical and environmental level. To address this gap, this paper highlights the way from structured data acquisition to setup of an energy value stream map (EVSM) for AM process chains in end-use part production, augmenting methods of lean manufacturing by the energy dimension. Consequently, it contributes to a holistic and transparent process chain perspective to assess AM as a manufacturing alternative. The proposed methodology is applied to a case study covering two different process chains, a first based on powder bed fusion via Multi-jet Fusion (MJF) and a second utilizing vat-photopolymerization via Continuous Liquid Interphase Printing (CLIP). While the MJF process chain’s energetical hot spot is situated in the printing process itself, the hot spot for CLIP is found in thermal post-processing, exceeding the comparably efficient printing process by magnitudes and ultimately resulting in higher energy intensity per part compared to the MJF process chain. These results highlight the necessity of a holistic evaluation method for complete AM-based process chains and their influence on the product properties. Insights may help engineers, designers and decision makers in pre-selection of suitable manufacturing strategies with a more complete view on AM process chains.

关键词： Additive manufacturing rapid manufacturing process chains value stream mapping sustainable manufacturing decision support

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DECOMPOSITION OF INDUSTRIAL SYSTEMS FOR ENERGY EFFICIENCY OPTIMIZATION WITH OPTTOPO

arXiv

引用

arXiv 2022年

作者： Thiele, Gregor Johanni, Theresa Sommer, David Krüger, Jörg Department for Process Automation and Robotics Fraunhofer Institute for Production Systems and Design Technology IPK Germany Faculty of Electrical Engineering and Computer Science Technical University of Berlin Berlin Germany Weierstrass Institute for Applied Analysis and Stochastics Berlin Germany Institute for Machine Tools and Factory Management Technical University of Berlin Berlin Germany

The operation of industrial facilities is a broad field for optimization. Industrial plants are often a) composed of several components, b) linked using network technology, c) physically interconnected and d) complex regarding the effect of set-points and operating points in every entity. This leads to the possibility of overall optimization but also to a high complexity of the emerging optimization problems. The decomposition of complex systems allows the modeling of individual models which can be structured according to the physical topology. A method for energy performance indicators (EnPI) helps to formulate an optimization problem. The optimization algorithm OptTopo achieves efficient set-points by traversing a graph representation of the overall system. © 2022, CC BY.

关键词： Optimization

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A bibliometric review on applications of lignocellulosic fibers in polymeric and hybrid composites: Trends and perspectives

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Heliyon 2024年第19期10卷 e38264页

作者： Santos, Caroliny M. Santos, Thiago F. Rao, H Jeevan Silva, F. Higor V.A. Mavinkere Rangappa, Sanjay Boonyasopon, Pawinee Siengchin, Suchart Souza, D.F.S. Nascimento, J.H.O. Postgraduate Program in Chemical Engineering Technology Center Federal University of Rio Grande do Norte Av. Prof. Sen. Salgado Filho 3000 Natal 59072-970 Rio Grande do Norte Brazil Department of Mathematics School of Sciences and Humanities Nazarbayev University Astana 010000 Kazakhstan Natural Composites Research Group Lab Department of Materials and Production Engineering The Sirindhorn International Thai-German School of Engineering (TGGS) King Mongkut's University of Technology North Bangkok (KMUTNB) Bangkok Thailand Department of Design Management and Business Development Faculty of Architecture and Design King Mongkut's University of Technology North Bangkok (KMUTNB) Bangkok Thailand

Over the past 10 years, materials science and engineering have shown increasing interest in incorporating lignocellulosic fibers into polymer and hybrid composites (LCF-CPH). This bibliometric analysis, covering the period 2012 to 2022, examines the current state of research on the application of these fibers in composites, with the aim of identifying significant contributions, new trends, and possible future directions. The analysis included a comprehensive database search using specific criteria, which revealed a significant increase in research activity on a variety of lignocellulosic fibers, such as flax, jute, hemp and sisal. This growth is particularly evident in the packaging, automotive, aerospace and construction industries. Hybrid composites based on these fibers have gained prominence due to their enhanced properties, which include improvements in mechanical, thermal and environmental characteristics. The findings of this research have significant implications for governments, corporations, and academic institutions. Researchers gain a deeper understanding of emerging trends, industry gains valuable insights into the advantages of adopting lignocellulosic fibers, and policymakers gain essential information to support the development of sustainable composites. In the field of advanced composites and sustainable materials, this work lays a solid foundation for future research and industrial applications. © 2024

关键词： Applications Composites Natural fibers Polymers

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Reconstructing the system coefficients for coupled harmonic oscillators

arXiv

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arXiv 2024年

作者： Bartsch, Jan Barakat, Ahmed A. Buchwald, Simon Ciaramella, Gabriele Volkwein, Stefan Weig, Eva M. Department of Mathematics University of Konstanz Universitätsstrase 10 Konstanz78464 Germany /III Garching b. München85748 Germany Design and Production Engineering Faculty of Engineering Ain Shams University El-Sarayat St. 1 Abbaseya Cairo11517 Egypt MOX Lab Dipartimento di Matematica Politecnico di Milano Piazza Leonardo da Vinci 32 Milano20133 Italy Am Coulombwall 3a Garching b. München85748 Germany Schellingstr. 4 München80799 Germany

Physical models often contain unknown functions and relations. In order to gain more insights into the nature of physical processes, these unknown functions have to be identified or reconstructed. Mathematically, we can formulate this research question within the framework of inverse problems. In this work, we consider optimization techniques to solve the inverse problem using Tikhonov regularization and data from laboratory experiments. We propose an iterative strategy that eliminates the need for laboratory experiments. Our method is applied to identify the coupling and damping coefficients in a system of oscillators, ensuring an efficient and experiment-free approach. We present our results and compare them with those obtained from an alternative, purely experimental approach. By employing our proposed strategy, we demonstrate a significant reduction in the number of laboratory experiments *** Codes 34A30, 34A55, 34C15, 93B30 © 2024, CC BY-SA.

关键词： Iterative methods

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Digital ergonomics and digital work planning in university education: experiences from Germany and Austria

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Zeitschrift fur Arbeitswissenschaft 2022年第4期76卷 510-524页

作者： Sebastian Schlund Christiane Kamusella Verena Knott Thomas Löffler Lutz Engel Clara Fischer Patrick Rupprecht Klaus Bengler Angelika Bullinger-Hoffmann André Kaiser Alexander Kögel Research Unit of Human-Machine Interaction Technische Universität Wien Theresianumgasse 27 1040 Wien Austria. Faculty of Mechanical Science and Engineering Institute of Material Handling and Industrial Engineering Chair of Labor Engineering Technische Universität Dresden 01062 Dresden Germany. TUM School of Engineering and Design Chair of Ergonomics Technical University of Munich Boltzmannstr. 15 85748 Garching b. München Germany. Chair of Ergonomics and Innovation Management Technische Universität Chemnitz 09107 Chemnitz Germany. Institute for Production and Industrial Service Management Jade University Friedrich-Paffrath-Str. 101 26389 Wilhelmshaven Germany.

The publication presents an overview of the use of digital human models (DHM) in academic education at five exemplary universities in Germany and Austria. In addition to the presentation of different human models, the integration of them into the respective lectures is discussed. The teaching concepts of the individual courses of the universities, exercise examples and scenarios are presented. Experience shows that the active and independent use of digital ergonomics tools gives students pleasure and motivates them to deal intensively with complex tasks in terms of time and content. Feedback is consistently positive over all the involved lectures and universities. As a consequence of the recent Covid-19 pandemic, universities significantly increased online and blended learning. Based on the experience with the use of digital human models, the paper derives recommendations for future developments. To sustain global value chains, companies are increasingly planning trans-regionally adapted products and production processes. Tools for digital ergonomics contribute to increasing competitiveness by using prospective working methods. Companies increasingly need experts with the corresponding know-how. Firmly anchoring the topic of digital ergonomics in relevant subjects of university teaching is therefore a prerequisite for this transfer of trained graduates.

关键词： Digital ergonomics Digital factory Digital human modeling Ergonomic product and production planning Human factors university teaching

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The finite cell method for the prediction of machining distortion caused by initial residual stresses in milling

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Procedia CIRP 2021年 102卷 144-149页

作者： M. Landwehr S. Schmid V. Holla P. Ganser T. Bergs M. Ruess K.-U. Schröder Fraunhofer Institute for Production Technology IPT Steinbachstrasse 17 52074 Aachen Germany Institute of Structural Mechanics and Lightweight Design (SLA) of RWTH Aachen University Wüllnerstrasse 7 52062 Aachen Germany Laboratory for Machine Tools and Production Engineering (WZL) of RWTH Aachen University Campus-Boulevard 30 52074 Aachen Germany Faculty of Mechanical and Process Engineering Düsseldorf University of Applied Sciences Münsterstrasse 156 40476 Düsseldorf Germany

Machining distortion caused by residual stresses is one of the major challenges in the production of thin-walled monolithic parts, which are widely used in the aerospace industry. This distortion often results in large deviations in form and position outside the tolerance requirements of the part. Time-consuming and cost-intensive running-in processes or manual reworking are therefore necessary to meet the tolerances of the parts. Current research mainly uses the finite element method (FEM) to predict machining distortion caused by residual stresses. However, the disadvantage of the FEM is the high manual effort required to generate a computational mesh of the in-process workpiece (IPW). Moreover, the FEM demands a very fine mesh, which has to be frequently updated by remeshing, to be in good agreement with the IPW. This leads to high computation times overall. In this paper, a novel machining distortion prediction method based on the Finite Cell Method (FCM) is presented. A major advantage of FCM compared to the established FEM in the context of milling simulation is the decoupling of the computational mesh and the IPW geometry, which allows for analysis updates of the modified IPW due to material removal, without the need for expensive re-meshing. Thus, the time complexity of the simulation can be reduced significantly. The milling process of a thin-walled part made of Ti-6Al-4V was considered to demonstrate the overall simulation approach.

关键词： Finite cell method Finite element method Machining distortion prediction Residual stress Milling Ti-6Al-4V

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Preliminary Results for Detection Evaluation in Failure Modes Study: 600 kW Wind Turbine Case Study

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Journal of engineering Science and Technology Review 2020年第6期13卷 92-98页

作者： Papatsounis, A.G. N Botsaris, P. Pistofidis, P.P. Democritus University of Thrace School of Engineering Dep. of Production Engineering and Management Lab. of mechanical Design Faculty of Materials Processes and Mechanics Greece

In recent years, the need for renewable and sustainable energy is greater than ever before. Wind turbines in a variety of sizes, appear in every available area and participate in our effort to reverse the energy crisis. However, these complex electromechanical systems are defined by low availability and substantial downtime periods. The Levelised Cost of Energy (LCOE) and the Internal Rate of Return (IRR) only recently started to be encouraging for investors. One of the key factors to be taken into consideration is that the reliability of these systems is often compromised due to their ever-growing nominal power and harsh operating conditions, fault appearances increase exponentially from 1 MW wind turbine to 10 MW or more. To assess the reliability of a case-study wind turbine of 600 kW, a Failure Modes and Effects Analysis (FMEA) was used to identify the potential causes of downtimes. In this paper, a novel way to approach detection evaluation in the FMEA study is proposed. The results indicate a reliable way to identify the most critical components of a complex system. © 2020 School of Science, IHU. All rights reserved.

关键词： Wind turbines

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Application of RISA grinding method to multiple optical glasses

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Procedia CIRP 2022年 108卷 454-458页

作者： Hinata Takamaru Tappei Kawasato Kentaro Watanabe Masahiko Fukuta Katsutoshi Tanaka Yusuke Chiba Hidebumi Kato Mikinori Nagano Yasuhiro Kakinuma Department of System Design Engineering Faculty of Science and Technology Keio University 3-14-1 Hiyoshi Kohoku-ku Yokohama 223-8522 Japan Nano Processing System Division Shibaura Machine Co. Ltd. 2068-3 Ohoka Numazu 410-0022 Japan Production Headquarters Nikon Corp. 1-10-1 Asamizo-dai Minami-ku Sagamihara 252-0328 Japan

A more efficient and precise grinding method for optical glasses is demanded to improve lens quality and productivity. The Reaction Induced Slurry Assisted (RISA) grinding method enhances the ability of ductile regime grinding by utilizing the chemical mechanical action of cerium oxide slurry. In this study, the grinding performance of RISA grinding to multiple optical glasses is experimentally evaluated. The result shows that RISA grinding efficiently produces a fine quality surface of crown glass with high Si-O bond content.

关键词： Ultra-precision grinding Chemical mechanical grinding Optical glasses

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Upscaling strategies for polymer additive manufacturing: an assessment from economic and environmental perspective for SLS, MJF and DLP

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Procedia CIRP 2021年 104卷 653-658页

作者： Sebastian Thiede Mathias Wiese Christoph Herrmann Manufacturing Systems Faculty of Engineering Technology Department of Design Production & Management University of Twente De Horst 2 Building 20 Enschede 7522 LW The Netherlands Polymer Additive Manufacturing Center AUDI AG Auto-Union-Straße 1 Ingolstadt 85045 Germany Chair of Sustainable Manufacturing and Life Cycle Engineering Institute of Machine Tools and Production Technology Technische Universität Braunschweig Langer Kamp 19b Braunschweig 38106 Germany

Without a question, additive manufacturing (AM) technologies are of strong and even further increasing importance nowadays. While incorporating strong potentials in context of customer-individual geometries, there are challenges when it comes to upscaling of production volumes due to long process times. The upscaling characteristics also differ among the available AM technologies. Against this background, this paper introduces and analyses different upscaling strategies from AM process perspective (for MJF, SLS and DLP) in context of economic and environmental performance criteria.

关键词： Type your keywords here separated by semicolons

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Evaluation of different flow stress laws coupled with a physical based ductile failure criterion for the modelling of the chip formation process of Ti-6Al-4V under broaching conditions

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Procedia CIRP 2019年 82卷 65-70页

作者： G. Ortiz-de-Zarate A. Sela F. Ducobu M. Saez-de-Buruaga D. Soler T.H.C. Childs P.J. Arrazola Mondragon Uniberstitatea Faculty of Engineering Loramendi 4 Arrasate-Mondragón 20500 Spain University of Mons (UMONS) Faculty of Engineering (FPMs) Machine Design and Production Engineering Lab 7000 Mons Belgium School of Mechanical Engineering University of Leeds Leeds LS29JT UK

During the machining of Ti-6Al-4V the changing deformation mechanisms produce a complex microstructure of segmented chips, which directly influenced tool-wear and process stability. Numerical simulation could give an insight into the physical phenomena involved in chip segmentation, but its accuracy is directly related to the reliability of the input parameters. In this work, therefore, three different flow stress law were evaluated coupled with a physical based ductile failure criterion, which depends on stress triaxiality and temperature. To this end, the flow stress laws were implemented in the finite element software AdvantEdge by programming user-defined subroutines. The resulting FEM models were compared with orthogonal cutting experimental tests (tubular/linear), analyzing different fundamental outputs (machining forces, temperatures in the workpiece and chip morphology). All the FEM models showed good agreement with the experimental results.

关键词： FEM machining Ti-6Al-4V orhtogonal cutting broaching

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