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8th IFIP WG 5.5 International Precision Assembly Seminar, IPAS 2018

作者： Schmidt, Marek Wittsock, Volker Professorship for Machine Tools and Forming Technology Chemnitz University of Technology Reichenhainer Str. 70 Chemnitz09126 Germany

ISBN: (纸本)9783030059309

In order to realize resource-efficient products and manufacturing processes, lightweight construction solutions have become enormously significant in many areas. Generally, material savings are always done at the expense of rigidity. However, additional weight can be saved through functional integration. One possibility is given by the functional material piezoceramic. This material can be used as sensor or actuator. A new approach for the structural integration of piezoceramic in sheet metals is with the technique joining by forming. Therefore, PZT fibers are assembled in a local microstructure of a sheet metal, which is followed by the joining operation. The article is a contribution to transfer this approach into a high-volume production process, which is necessary for the industrial area to take root. Manufacturing processes for PZT fiber arrays with minimal manufacturing tolerances are presented. The process of stacking PZT plates with distance elements and subsequent dicing into slices is shown as a suitable variant. Furthermore, an automated assembly system is tested with regard to the measuring technology. A machine vision and a chromatic confocal sensor are compared in the assembly system. The results show that the machine vision system is better suited for pose measurement of the PZT fiber arrays and the chromatic confocal sensor achieves better results for the microstructured sheet metals. © 2019, IFIP International Federation for Information Processing.

关键词： Metals

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Monitoring the evolution of dimensional accuracy and product properties in property-controlled forming processes

arXiv

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arXiv 2023年

作者： Stebner, Sophie Charlotte Martschin, Juri Arian, Bahman Dietrich, Stefan Feistle, Martin Hütter, Sebastian Lafarge, Rémi Laue, Robert Li, Xinyang Schulte, Christopher Spies, Daniel Thein, Ferdinand Wendler, Frank Wrobel, Malte Vasquez, Julian Rozo Dölz, Michael Münstermann, Sebastian Integrity of Materials and Structures RWTH Aachen University Aachen Germany Institute of Forming Technology and Lightweight Components Technische Universität Dortmund Dortmund Germany Paderborn University Paderborn Germany Institute for Applied Materials - Material Science KIT Karlsruhe Karlsruhe Germany Garching Germany Institute of Materials and Joining Technology Otto-von-Guericke Universität Magdeburg Germany Forming and Machining Processes Technische Universität Dresden Dresden Germany Institute for Machine Tools and Productions Processes Professorship Virtual Production Engineering Chemnitz University of Technology Chemnitz Germany RWTH Aachen University Aachen Germany Institute of Automatic Control RWTH Aachen University Aachen Germany Institute for Production Engineering and Forming Machines Technische Universität Darmstadt Darmstadt Germany Institut für Geometrie und Praktische Mathematik RWTH Aachen University Aachen Germany Professorship Measurement and Sensor Technology Chemnitz University of Technology Chemnitz Germany Karlsruhe Germany Dortmund Germany

As recent trends in manufacturing engineering disciplines show a clear development in the sustainable as well as economically efficient design of forming processes, monitoring techniques have been gaining in relevance. In terms of monitoring of product properties, most processes are currently open-loop controlled, entailing that the microstructure evolution, which determines the final product properties, is not considered. However, a closed-loop control that can adjust and manipulate the process actuators according to the required product properties of the component will lead to a considerable increase in efficiency of the processes regarding resources and will decrease postproduction of the component. For most forming processes, one set of component dimensions will result in a certain set of product properties. However, to successfully establish closed-loop property controls for the processes, a systematic understanding of the reciprocity of the dimensions after forming and final product properties must be established. This work investigates the evolution of dimensional accuracy as well as product properties for a series of forming processes that utilize different degrees of freedom for process control. Copyright © 2023, The Authors. All rights reserved.

关键词： Microstructure

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Inductive Sintering Module for Improved Multi-Die Attach in the Field of Power Packaging

Inductive Sintering Module for Improved Multi-Die Attach in ...

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IEEE CPMT Symposium Japan

作者： Christian Hofmann Patrick Rochala Martin Kroll Sushant Panhale Mario Baum Harald Kuhn Kiyoshi Oi Masaki Sanada Kei Murayama Department System Packaging Fraunhofer Institute for Electronic Nano Systems ENAS Chemnitz Germany Professorship for Forming and Joining Institute for Machine Tools and Production Processes (IWP) Chemnitz University of Technology Chemnitz Germany Department Systems Engineering Fraunhofer Institute for Electronic Nano Systems ENAS Chemnitz Germany Fraunhofer Institute for Electronic Nano Systems ENAS Chemnitz Germany Process Development Dept. SHINKO ELECTRIC INDUSTRIES CO. LTD. Nagano Japan

This work presents a heating technology for multi-die attach based on inductive silver sintering. Thus, the heat for the sintering reaction is confined locally to the bond region, avoiding heating of the entire power ...

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Monitoring concept for structural integration of PZT-fiber arrays in metal sheets:a numerical and experimental study

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International Journal of Smart and Nano Materials 2018年第1期9卷 56-67,I0003页

作者： Welf-Guntram Drossel Andreas Schubert Matthias Putz Hans-Joachim Koriath Volker Wittstock Sebastian Hensel Alexander Pierer Benedikt Müller Marek Schmidt Fraunhofer Institute for Machine Tools and Forming Technology ChemnitzGermany Professorship for Adaptronics and Lightweight Design Chemnitz University of TechnologyChemnitzGermany Professorship Micromanufacturing Technology Chemnitz University of TechnologyChemnitzGermany Professorship for Machine Tools and Forming Technology Chemnitz University of TechnologyChemnitzGermany

The technique joining by forming allows the structural integration of piezoceramic fibers into locally microstructured metal sheets without any elastic interlayers.A high-volume production of the joining partners causes in statistical deviations from the nominal dimensions.A numerical simulation on geometric process sensitivity shows that the deviations have a high significant influence on the resulting fiber stresses after the joining by forming operation and demonstrate the necessity of a monitoring *** this basis,the electromechanical behavior of piezoceramic array transducers is investigated experimentally before,during and after the joining *** piezoceramic array transducer consists of an arrangement of five electrical interconnected piezoceramic *** findings show that the impedance spectrum depends on the fiber stresses and can be used for in-process monitoring during the joining *** on the impedance values the preload state of the interconnected piezoceramic fibers can be specifically controlled and a fiber overload.

关键词： Impedance spectroscopy joining by forming process monitoring function integration sensitivity

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Development and Validation of Bone Models using Structural Dynamic Measurement Methods

Development and Validation of Bone Models using Structural D...

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作者： Neupetsch, Constanze Hensel, Eric Werner, Michael Meißner, Sven Troge, Jan Drossel, Welf-Guntram Rotsch, Christian Chemnitz University of Technology Professorship for Adaptronics and Lightweight Design in Production Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU Chemnitz/Dresden Germany

Vibration measurement and signal analysis methods are common to evaluate the functionality and characteristics of technical components in different industrial and scientific areas. Modal analysis for example is a standard method to characterize the dynamic behavior of a structure and enables the development of validated bone models. The state of the art of analyzing bone structures does not include the modal damping, although it has a significant influence on the dynamic characteristics. Within the presented investigations, the modal analyses have been performed contactless with respect to excitation and response acquisition, which implies that there are no influences of shakers or sensor couplings. Therefore, an automatic impulse hammer and a 3D Scanning Laser Doppler Vibrometer were used for excitation and response detection. Various supports of the test specimens, surface pretreatments, excitation points and excitation impulses were examined to optimize the measurement setup and process. Experimental modal analysis data were analyzed by curve fitting methods to determine the modal parameters. To evaluate different structures and effects of damping, 3D printed artificial bones and animal in vitro bones were used to perform the measurements. To produce the cortical layer of the artificial bone models, volume models were generated based on medical image data and printed by polyamide-based selective laser sintering. The cancellous bone was represented by different foam fillings for the artificial bones. Thereby, the variation of the porosity was achieved by using different mixing ratios of polyurethane foam and hardener. Furthermore, the modal damping parameters were determined from the measurement of animal bones. The measurement time was optimized during the practical implementation of the parameter determination to minimize the influence of drying and decomposition processes on the measurement results. © 2019 by Walter de Gruyter Berlin/Boston.

关键词： Structural dynamics

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Working Gap Analysis in Electrochemical Precision Machining of External Geometries with Ring Cathodes

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Procedia CIRP 2020年 95卷 662-667页

作者： Ingo Schaarschmidt Matthias Hackert-Oschätzchen Gunnar Meichsner Philipp Steinert Mike Zinecker Andreas Schubert Professorship Micromanufacturing Technology Chemnitz University of Technology 09107 Chemnitz Germany Chair of Manufacturing Technology with Focus Machining Otto von Guericke University Magdeburg 39106 Magdeburg Germany Fraunhofer Institute for Machine Tools and Forming Technology 09126 Chemnitz Germany

Pulsed electrochemical machining (PECM) with oscillating cathode is a non-conventional manufacturing technology to machine complex precision geometries independent from the mechanical properties of the workpiece material. PECM with oscillating cathode is an advanced development of conventional ECM by applying a pulsed electric current in conjunction with an oscillating movement of the cathode. Result is electrochemical precision machining with a more stable process combined with better accuracy and quality. This work focuses on the analysis of the resulting side working gap in electrochemical precision machining of external geometries by applying PECM. Therefore, the height of a ring cathode was varied to adjust the cathode inner surface. The resulting side working gap was studied through multiscale multiphysics simulation applying COMSOL Multiphysics as well as experiments applying a PEMCenter 8000. As main result, the increase of the resulting side working gap as consequence of an increasing cathode inner surface will be analysed in detail.

关键词： Pulsed electrochemical machining (PECM) Side working gap Multiscale multiphysics modelling

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Haptic feedback is more important than VR experience for the user experience assessment of in-car human machine interfaces 31st

Haptic feedback is more important than VR experience for the...

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31st CIRP Design Conference 2021, CIRP Design 2021

作者： Schölkopf, Lasse Lorenz, Mario Stamer, Mareike Albrecht, Lina Klimant, Philipp Hammer, Niels Tümler, Johannes Volkswagen AG Berliner Ring 2 Wolfsburg38436 Germany Professorship for Production Systems and Processes Chemnitz University of Technology Reichenhainer Straße 70 Chemnitz09126 Germany Department of Orthopedics Trauma and Plastic Surgery University Hospital Leipzig Liebigstraße 20 Leipzig04103 Germany Department of Macroscopic and Clinical Anatomy Medical University of Graz Harrachgasse 21 Graz8010 Austria Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 Dresden01187 Germany Professur Ingenieurinformatik Anhalt University of Applied Sciences Bernburger Str. 55 Köthen06366 Germany

The user experience (UX) of a product is important for a customer's decision, especially in the automotive sector. In recent years, a frontloading of UX assessments from physical prototypes to virtual prototypes has occurred. Nevertheless, there are clear indications that established UX assessments methods cannot simply be transferred 1-to-1 from real to virtual evaluation setups as results get biased. For the UX assessment of an in-car human machine interface (HMI) the haptic properties of the knobs and buttons are just as important as their visual features. Therefore, it is mandatory to also simulate the haptic behavior of the in-car HMI in virtual reality (VR) assessment scenarios. However, accurately simulating this haptic behavior adds considerable costs and effort, diminishing the beneficial effects of VR UX assessments. Due to confidentiality reasons the volunteering participants of VR UX studies in the automotive sectors are typically employees with a varying degrees of VR experience. It is unknown if this gap in VR experience biases the results of UX assessments in VR. This paper presents a UX assessment study of an in-car HMI in VR in comparison to reality. From a practitioners viewpoint two research question are investigated: (1) How much is the UX assessment impaired by missing haptic simulation? (2) Does VR experience influence UX assessment ratings in VR? The results show that missing haptic feedback severely diminishes UX ratings, leaving no doubt that meaningful UX assessments in VR can only be performed when haptic is included. This means that more effort has to be put into earlier VR assessments severely reducing its benefits compared to UX assessments with physical prototypes. However, the VR experience of the participants only has a slight effect on the UX assessment results. © 2021 Elsevier B.V.. All rights reserved.

关键词： Virtual reality

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Influence on the microstructure of powder metallurgical metal foam by means of mechanical alloying 22nd

Influence on the microstructure of powder metallurgical meta...

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22nd Symposium on Composites, 2019

作者： Siebeck, Steve Trautmann, Maik Hohlfeld, Jörg Hipke, Thomas Wagner, Guntram Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 Chemnitz09126 Germany Chemnitz University of Technology Professorship of Composites and Material Compounds Erfenschlager Straße 73 Chemnitz09125 Germany

ISBN: (纸本)9783035714531

Due to the process, metal foams produced by powder metallurgy have an inhomogeneous pore structure. The pore size variations from a few tenths of a millimeter up to the centimeter range is so typical. This leads to inconstant properties and makes the predictability of metal foam based components difficult. The present work deals with the approach to precondition the feedstock powder for the production of metal foams by mechanical alloying. Thereby, the homogeneous distribution of the blowing agent TiH2 is already present in the so-called composite powder. In addition, there is the possibility to add reinforcement particles with regard to a further improvement of the mechanical properties. Overall, this leads to a rather wide range of possible influencing factors and parameters to be varied. Accordingly, the present work is only a preview of a broad experimental program, taking into account the design of experiments and is currently being processed. In this first study, an alloy AA6060 has been used as the matrix material. The evaluated method provides a finer pore structure associated with a modified foaming behavior. © 2019 Trans Tech Publications Ltd, Switzerland.

关键词： Pore structure

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Implementation of the machine Tool-Specific Current and Voltage Control Characteristics in Multiphysics Simulation of Electrochemical Precision Machining

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Procedia CIRP 2019年 82卷 237-242页

作者： Ingo Schaarschmidt Matthias Hackert-Oschätzchen Gunnar Meichsner Mike Zinecker Andreas Schubert Professorship Micromanufacturing Technology Chemnitz University of Technology 09107 Chemnitz Germany Fraunhofer Institute for Machine Tools and Forming Technology IWU 09126 Chemnitz Germany

In this study a multiphysics simulation model of the pulsed electrochemical machining (PECM) with oscillating cathode is shown. The focus of this study is on the implementation of machine tool-specific control characteristics in combination with physical phenomena and material removal. As a result, the implementation of the machine tool control characteristics leads to an increase of simulation accuracy of the multiphysics model. The simulation results are compared with results of previous simulations and experimental investigations.

关键词： Electrochemical machining (ECM) Material removal High strength steel

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Energetic evaluation of press hardening processes

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Procedia Manufacturing 2019年 33卷 367-374页

作者： Enrique Meza-García Anja Rautenstrauch Michael Bräunig Verena Kräusel Dirk Landgrebe Technische Universitaet Chemnitz Faculty of Mechanical Engineering Institute for Machine Tools and Production Processes Professorship for forming and joining. Reichenhainer Str.70 D-09126 Chemnitz Germany Technische Universitaet Chemnitz Faculty of Mechanical Engineering Institute for Machine Tools and Production Processes Professorship for Machine Tools and Forming Technology. Reichenhainer Str.70 D-09126 Chemnitz Germany

The awareness and commitment to carefully use energy and other resources is increasing, in view of climate change and the shortage of resources. Sustainable practice starts with sustainable production. The press hardening of sheet and tube metal components offers a range of optimization approaches. It becomes clear that a holistic view of the life cycle of components and products is essential. On the one hand, press hardening manufacturing process is significantly more energy demanding than conventional deep drawing process. On the other hand, they are also associated with significant energy and life cycle savings in the utilization phase of the manufactured product. The main focus of this work was on the visualization of energy consumption as well as the development of innovative energy-efficient process chains for press hardening. Based on a technological analysis, the investigated process chains were energetically evaluated and approaches to improve the energy balance were deduced.

关键词： energy-efficiency press hardening energy evaluation

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