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Methodology for the early analysis and evaluation of the resource efficiency of process chains for manufacturing hybrid structures

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Procedia Manufacturing 2019年 33卷 430-437页

作者： C. Symmank J. Boll A. Rautenstrauch A. Graf L. Markov R. Decker A. Schmidt U. Götze B. Awiszus V. Kräusel D. Landgrebe L. Kroll Professorship of Management Accounting and Control Chemnitz University of Technology Thüringer Weg 7 09126 Chemnitz Germany Professorship Virtual Production Engineering Chemnitz University of Technology Reichenhainer Straße 70 09126 Chemnitz Germany Professorship for Forming and Joining Chemnitz University of Technology Reichenhainer Straße 70 09126 Chemnitz Germany Department of Lightweight Structures and Polymer Technology Chemnitz University of Technology Reichenhainer Straße 31/33 09126 Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany

To ensure a successful development of resource-efficient and sustainable technologies, products, and production processes, it is essential to support R&D activities in early design stages. Thus, amongst others an appropriate assessment should be accomplished, which captures the high complexity and interdependencies of process chains, considers the technological feasibility, the energetic and economic benefit as well as the robustness as facets of resource efficiency, and hence, serves as a basis for deriving impulses for R&D activities. A promising evaluation methodology for such assessments is the Multidimensional Evaluation Method for Process Chains of HybrId Structures (MEMPHIS). In this paper, MEMPHIS is outlined and illustrated for an innovative process chain for producing hybrid laminates with sensor functionality. As a result, the paper will contribute to the further development of the methodology, show its applicability, and provide insights into the innovative technology.

关键词： cost effectiveness energy efficiency hybrid assembled composites robustness sustainable manufacturing processes

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Evaluation of thermo-energetic behavior for demand-oriented operating of machine tool cooling systems

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Procedia Manufacturing 2018年 21卷 213-220页

作者： Joachim Regel Du Xu Michael Bräunig Volker Wittstock Matthias Putz Institute for Machine Tools and Production Processes Technische Universität Chemnitz Reichenhainer Str. 70 09126 Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Str. 88 09126 Chemnitz Germany

In state of the art machine tools, structural thermal displacement is commonly reduced by cooling and tempering measures. The application of these measures frequently counteracts the original goal of energy efficiency. To design demand-oriented cooling systems, this paper presents a method to evaluate cooling measures and control parameters by means of a variance-based sensitivity analysis regarding the thermo-energetic efficiency. The evaluation is carried out by using the example of a machine bed made of high performance concrete. The integrated fluid-air cooling system with fan speed control and the bed structure are modelled by lumped elements. In addition to the PID-control of the cooling fluid temperature, the evaluation considers a two-position control of separately controllable cooling circuits and the influence of ambient temperature. The criteria to evaluate are temperature differences within the machine structure, the dissipated heat and their proportions to deployed electrical energy.

关键词： machine tool sensitivity analysis thermal measures cooling system energy efficiency simulation experiment thermal modeling

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A critical review of FEM models to simulate the nano-impact test on PVD coatings 5

A critical review of FEM models to simulate the nano-impact ...

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5th International Conference of Engineering Against Failure, ICEAF-V 2018

作者： Skordaris, Georgios Bouzakis, Konstantinos Charalampous, Paschalis Laboratory for Machine Tools and Manufacturing Engineering Mechanical Engineering Department Aristotle University of Thessaloniki Greece Fraunhofer Project Centre Coatings in Manufacturing LMTME Fraunhofer Institute for Production Technology Aachen Germany

Nano-impact test is a reliable method for assessing the brittleness of PVD coatings with mono- or multi-layer structures. For the analytical description of this test, a 3D-FEM Finite Element Method (FEM) model and an axis-symmetrical one were developed using the ANSYS LS-DYNA software. The axis-symmetrical FEM simulation of the nano-impact test can lead to a significantly reduced computational time compared to a 3D-FEM model and increased result's accuracy due to the denser finite element discretization network. In order to create an axissymmetrical model, it was necessary to replace the cube corner indenter by an equivalent conical one with axis-symmetrical geometry. Results obtained by the developed FEM models simulating the nano-impact test on PVD coatings with various structures were compared with experimental ones. Taking into account the sufficient convergence between them as well as the reduced calculation time only in the case of an axis-symmetrical model, the latter introduced numerical procedure can be effectively employed to monitor the effect of various coating structures on their brittleness. © The Authors, published by EDP Sciences, 2018.

关键词： Finite element method

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A load-adaptive and predictive control of energy-efficient building automation in production environment

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Procedia CIRP 2019年 79卷 245-250页

作者： Beiyan Zhou Jayaaditya Chikkala Robert Schmitt Fraunhofer Institute for Production Technology IPT Steinbachstr. 17 Aachen 52074 Germany Laboratory for Machine Tools and Production Engineering (WZL) of RWTH Aachen University Production Engineering Cluster Campus-Boulevard 30 Aachen 52074 Germany

The energy efficiency of production processes has been widely researched. However, researchers neglect the periphery energy, which deals with heating, ventilation, air conditioning, blinds and lighting for production environment. In this paper, a load-adaptive and predictive building automation control connected with production control systems and weather forecasts aims to reduce periphery energy consumption. A Nonlinear Model Predictive Control (NMPC) is developed in MATLAB to look for an optimization of control inputs while utilizing thermal or illumination effects from production activities and atmosphere. Compared with conventional controllers, NMPC reaches a more desirable comfort level and a significant reduction of energy consumption.

关键词： Energy efficieny Periphery energy Building automation Production control systems Nonlinear model predictive control

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Requirements for Volume Flexibility and Changeability in the Production of Electrified Powertrains

Requirements for Volume Flexibility and Changeability in the...

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International Electric Drives Production Conference (EDPC)

作者： Jens Niemann Christoph Eckermann Andreas Schlegel Thomas Büttner Johannes Stoldt Matthias Putz Planning and Production of Electrified Powertrains BMWAG Munich Germany Machine Tools Production Systems and Machining Fraunhofer-Institute for Machine Tools and Forming Technology IWU Chemnitz Germany

ISBN: (纸本)9781728101491;9781728101484

Electro mobility represents a key concept in response to current trends in the mobility sector. Yet, strong uncertainties regarding future demand of electric vehicles pose major challenges for capacity planning and procurement. Current forecasts predict a total market share of electric vehicles between 3 % and 24 % in 2025. This paper presents a study that aims to shed light on the challenges of capacity planning. We provide insights on the requirements of volume flexibility and changeability in the production and purchasing of electrified powertrains. The study relies on expert interviews in the field of production and procurement. We interviewed 13 managers from three leading, premium German carmakers. The interviews were conducted using a semi-structured guide that addresses six hypotheses concerning market development, long-term capacity planning, identification and definition of courses of action, interdependencies between the production and the supplier, specifics of the production system for electrified powertrains, and access to resources. The study's results show that demand volatility of electrified vehicles is expected to persist for the next 5 years. Consequently, existing demand uncertainties lead to a high number of different planning scenarios. This challenges capacity planners to provide enough capacity by relying on flexibility or changeability measures. Differences in supplier structures further require automotive OEM to change their mindset and to implement new processes. Despite those substantial changes, however, the task of purchasing remains vital to prevent quality losses or significant cost increases. Lastly, we show the importance of integrating supplier and purchasing department capacity planning process. Our main results indicate the need for developing a decision support system. It supports supply chain capacity planning of electric drive trains in order to enable fast and efficient reactions to volatile volumes.

关键词： Capacity planning Supply chains Interviews Electric vehicles Mechanical power transmission Uncertainty

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Effect of atmospheric pressure plasma treatment of glass fibers on the composite strength of endless fiber-reinforced injection molded components 4th

Effect of atmospheric pressure plasma treatment of glass fib...

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4th International Conference on Composite Materials and Materials Engineering, ICCMME 2019

作者： Gebken, Tobias Sachs, Rüdiger Kühn, Markus Ihde, Jörg Dröder, Klaus Wilken, Ralph Technische Universität Braunschweig Institute of Machine Tools and Production Technology Langer Kamp 19b Braunschweig38106 Germany Wiener Str. 12 Bremen28359 Germany Fraunhofer Project Centre Wolfsburg c/o Open Hybrid LabFactory e.V. Hermann-Münch-Str. 2 Wolfsburg38440 Germany

ISBN: (纸本)9783035714913

Injection molding is an efficient manufacturing process for short-fiber reinforced plastic components and is used for the production of semi-structural or geometrically complex components. To improve stiffness and strength, continuous fibers can be locally integrated inside the part during manufacturing. A local integration of fibers is not feasible for high output manufacturing processes but can be achieved by direct impregnation of endless fibers in the injection molding process. It is a challenging option to integrate endless fibers in injection molded parts in means of fiber position and infiltration. Thereby, the knowledge of the flow process of the injected melt must be precisely understood in means of orientation of the fibers to achieve a correct position. In previous works the process parameters for the impregnation of fibers and the composite behavior of untreated fibers were investigated. As a result, the surface pretreatment of the fibers can have an important effect on the composite and the direct impregnation of fibers. An important focus of this work is the pretreatment of glass fibers by plasma. The influence of the plasma parameters resulting on the adhesion properties between fiber and matrix and thus the bond strength of the composite are evaluated and measures for further adhesive property improvement are shown. © 2019 Trans Tech Publications, Switzerland.

关键词： Injection molding

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The Effect of Torsional Vibrations on Metal Cutting Dynamics

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Procedia CIRP 2018年 77卷 461-464页

作者： Andreas Otto Martin Kolouch Günter Radons Institute of Physics Chemnitz University of Technology 09107 Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany

The effect of torsional vibrations on the dynamics of metal cutting processes is studied. An extended dynamic process model is presented, where the spindle angle and the time delay are dynamic variables resulting in delay differential equations with state-dependent delay. Stability lobes are calculated based on the new extended process model and compared with results from the classical chatter theory with constant spindle speed and delay. For an ideal symmetric tool, stable cutting is characterized by a periodic spindle speed but still a constant delay. In this case, the main difference between the new extended and the classical model is a different periodic solution to periodic torsional tool displacements, which results only in slight modifications of the stability lobes. However, the new theory shows that it is important to consider tool asymmetries (e.g. runout), because this would result in periodically varying delays during stable cutting and larger stability changes due to torsional vibrations.

关键词： Metal Cutting Sawing Chatter Vibrations Stability State-dependent delay

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Manufacturing and replication of sub-10 μm micro-bowls for biomedical sensor systems 18

Manufacturing and replication of sub-10 μm micro-bowls for ...

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18th International Conference of the European Society for Precision Engineering and Nanotechnology, EUSPEN 2018

作者： Uhlmann, E. Hein, C. Polte, M. Polte, J. Dähne, L. Fraunhofer Institute for Production Systems and Design Technology IPK Germany Institute for Machine Tools and Factory Management IWF Technische Universität Berlin Germany Surflay Nanotec GmbH Germany

ISBN: (纸本)9780995775121

The technical implementation of a novel biosensor for the highly parallelized screening of biochemical binding reactions depends on the manufacturing of an array of micro-bowls with a diameter dB ≤ 10 μm with an aspect ratio ar ≥ 1. Since the operating principle of the biosensor is based on the stimulation of stationary optical waves in micro-spheres, micro-bowls for the immobilisation of these spheres in a microfluidic environment are necessary. Due to this operating principle, the micro-bowls need to separate the spheres from the fluid flow and ensure the careful adherence of single spheres, coincidently. Moreover, the pathway for the optical accessibility of the micro spheres should be unrestricted. This work presents a process chain for the manufacturing of microfluidic chips with an array of n ≥ 1,000 micro-spheres by ultra-precision milling of mold inserts, the replication by precision injection molding as well as experimental trial results. With regard to manufacturing of the mold inserts, the uniform and burr free ultraprecision milling of large aspect ratio micro posts was investigated within a parametric study. Furthermore, the replication of the micro-bowls was examined by taking the consistent replication of the entire bowl array, the adverse formation of fillets, and the replication of surfaces with optical functions into special account. By the analysis of the microfluidic and optical properties of the replicated structures, the correlation between mold manufacturing, replication, and operating conditions can be performed. © 2018 CURRAN-CONFERENCE. All rights reserved.

关键词： Biosensor Injection molding Micro-bowl Ultraprecision milling

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Sensorless fault detection in linear axes with dynamic load profiles

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Procedia Manufacturing 2018年 19卷 66-73页

作者： M. Putz C. Trimborn C. Naumann J. Fischer M. Naumann L. Gebel Fraunhofer-Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany Volkswagen AG Berliner Ring 2 38440 Wolfsburg Germany

Press lines are commonplace in the automotive industry. They typically use transfer systems to transport parts from one manufacturing stage to the next. Since these transfers are forced to endure great loads, both the gears and the shaft break fairly frequently and need to be replaced. Since every minute of downtime these maintenance tasks require costs manufacturers a lot of money, a condition monitoring system able to detect or predict damaged parts in linear drives would allow them to schedule maintenance so that downtime can be minimized and costs reduced. This paper presents a new method of fault detection for dynamic load profiles which is non-intrusive and requires no additional sensors. After a brief overview of the state of the art in fault detection and condition monitoring, the new method will be explained and demonstrated using measurement data from a press transfer.

关键词： Condition monitoring Servo system Motor current signature analysis

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Arc-based powder production of AlSi7Mg0.6

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Procedia Manufacturing 2019年 40卷 27-31页

作者： S. Dietrich M.F. Zaeh “Fraunhofer Research Institution for Casting Composite and Processing Technology IGCV Beim Glaspalast 5 D-86153 Augsburg” “Technical University of Munich Institute for Machine Tools and Industrial Management Boltzmannstr. 15 D-85748 Garching Germany”

This paper introduces arc-based powder production for additive manufacturing. Based on established processes, a new approach for powder production was developed, implemented and tested with an AlSi7Mg0.6 alloy. The arc-based powder was analyzed for particle size distribution, shape, flowability, oxygen content and material properties. All measurement results were compared to commercially purchased powder.

关键词： additive manufacturing powder powder on demand atomization thermal spraying wire arc spraying arc-based atomization laser powder bed fusion

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