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Temporal analysis of event-discrete alarm data for improved manufacturing

Procedia CIRP 2020年 93卷 742-746页

作者： Heiner Reinhardt Jan-Peter Bergmann Anke Stoll Matthias Putz Fraunhofer Institute for Machine Tools and Forming Technology IWU Reichenhainer Straße 88 09126 Chemnitz Germany

Efficient response to machine failures is crucial for improving machine availability. In practice, the number of alarms occurring during the operation of manufacturing systems could overwhelm even experienced machine operators. Manufacturing execution systems (MES) therefore often allow for alarm data acquisition as well as its filtering and aggregation to reduce the occurring information overload. However, manual configuration of these systems may be cumbersome and time-consuming. Hence, we propose an event-discrete method for temporal alarm data analysis to support the configuration process.

关键词： Man-machine system Maintenance Pattern recognition Knowledge management Algorithm Analysis Automation Condition monitoring Manufacturing system Complexity

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Laser structuring with DLIP technology of tungsten carbide with different binder content

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Procedia CIRP 2022年 111卷 601-604页

作者： Uwe Teicher Robert Baumann Yasmine Bouraoui Anas Ben Achour Andrés Fabián Lasagni Steffen Ihlenfeldt Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 01187 Dresden Germany Institute for Manufacturing Technology Technische Universität Dresden George-Baehr-Str. 3c 01069 Dresden Germany Fraunhofer Institute for Material and Beam Technology IWS Winterbergstraße 28 01277 Dresden Germany Institute of Mechatronic Engineering Technische Universität Dresden Helmholtzstraße 7a 01069 Dresden Germany

In machining, tool wear is one of the main influence factors for the resulting quality of the product. Several wear mechanisms have to be addressed to prevent unwanted deterioration of the tool integrity. For aluminium alloys, adhesion of the workpiece material on the cutting tool is one of the most challenging wear mechanisms. Engineering surface microtopographies has been proved as a convenient strategy to tackle this issue. Particularly, the direct laser interference patterning (DLIP) technique enables the integration of periodic structures on the micrometer or sub-micrometer scale. In this study the structuring of tungsten carbide with different cobalt content is presented. The interference of two laser beams leads to periodic line-like structures with a spatial period of 5.5 µm. A maximum structure depth of 2.2 µm is reached by controlling the processing parameters. Moreover, the wettability of the structured samples was analyzed by contact angle measurements with selected cooling lubricants, revealing a hydrophilic behavior with a decreased contact angle of 10°. This work gives an insight into the possibilities of structuring tungsten carbide materials with a picosecond laser source in combination with an innovative beam shaping setup from the point of view of an analysis to explore the formation of structured surfaces and their wetting behavior with cooling lubricants.

关键词： Laser structuring cutting tool DLIP Surface modification tungsten carbide

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A novel approach for increasing the traceability of 3D printed medical products

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Current Directions in Biomedical Engineering 2020年第3期6卷

作者： Matvieieva, Nataliia Neupetsch, Constanze Oettel, Markus Makdani, Varun Drossel, Welf- Guntram Fraunhofer Institute for Machine Tools and Forming Technology Iwu Nöthnitzer Straße 44 Dresden Germany

According to the European Medical Device Directive (MDR (EU) 2017/745), medical products of all risk classes are obliged to be labelled with Unique Device Identification Codes (UDI). In order to meet the requirements of the MDR, a novel method of identification for additively manufactured metallic products was developed at the fraunhofer institute for machine tools and forming technology (IWU). The method provides a product traceability within its production process and during the whole product lifespan, and also functions as a counterfeit protection. This paper shows the integration of a unique identification during an additive manufacturing process for a titanium part. The readout of the integrated identification was executed using ultrasonic and eddy current methods, as well as micro computed tomography. Obtained results are discussed in the paper. © 2020 by Walter de Gruyter Berlin/Boston 2020.

关键词： Laser beams

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High performance machining of continuous metal fibers with cascaded multi-stage profile tools

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Procedia CIRP 2021年 101卷 334-337页

作者： Uwe Teicher Tristan Lange Steffen Ihlenfeldt Fraunhofer Institute for Machine Tools and Forming Technology IWU Dresden 01187 Germany Technische Universität Dresden Institute of Manufacturing Technology Dresden 01062 Germany Technische Universität Dresden Institute of Mechatronic Engineering Dresden 01062 Germany

Metallic fibers are essential for applications in the chemical industry, the automotive industry for brake pads and, more recently, for the air conditioning modules. The most productive process to date for producing continuous fiber lines with fiber cross-sections between 50 and 150 µm is the application of cascaded multi-stage profile tools for cutting from semi-finished wire products. One challenge is the development of a technology for highly ductile materials made of aluminium, which are used as fiber materials in the area of refrigeration adsorbers. Preliminary studies have shown that high cutting speeds are necessary for machining. For this reason, a highly manually operated machine system was advanced to meet the requirements of high cutting speeds and to integrated a process monitoring system. For the first time, experimental investigations were able to show the interrelationships between set technology values and the effective machining forces for this process. Further investigations were done using the example of aluminium alloys 5019 for an analysis of a control system for wire breakage detection on the basis of force sensors.

关键词： machining aluminium metal fiber optimization

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Development and Validation of Bone Models using Structural Dynamic Measurement Methods

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Current Directions in Biomedical Engineering 2019年第1期5卷 343-345页

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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High performance machining of continuous metal fibers with cascaded multi-stage profile tools 9

High performance machining of continuous metal fibers with c...

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9th CIRP Conference on High Performance Cutting, HPC 2020

作者： Teicher, Uwe Lange, Tristan Ihlenfeldt, Steffen Fraunhofer Institute for Machine Tools and Forming Technology IWU Dresden01187 Germany Technische Universität Dresden Institute of Manufacturing Technology Dresden01062 Germany Technische Universität Dresden Institute of Mechatronic Engineering Dresden01062 Germany

ISBN: (纸本)9781713835431

Metallic fibers are essential for applications in the chemical industry, the automotive industry for brake pads and, more recently, for the air conditioning modules. The most productive process to date for producing continuous fiber lines with fiber cross-sections between 50 and 150 µm is the application of cascaded multi-stage profile tools for cutting from semi-finished wire products. One challenge is the development of a technology for highly ductile materials made of aluminium, which are used as fiber materials in the area of refrigeration adsorbers. Preliminary studies have shown that high cutting speeds are necessary for machining. For this reason, a highly manually operated machine system was advanced to meet the requirements of high cutting speeds and to integrate a process monitoring system. For the first time, experimental investigations were able to show the interrelationships between set technology values and the effective machining forces for this process. Further investigations were done using the example of aluminium alloys 5019 for an analysis of a control system for wire breakage detection on the basis of force sensors. © 2020 The Authors. Published by Elsevier B.V.

关键词： Automotive industry

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Modular instrument for the minimally invasive surgery with SMA actuation and control

Modular instrument for the minimally invasive surgery with S...

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International Conference on Shape Memory and Superelastic Technologies 2019, SMST 2019

作者： Braun, Dennis Weik, David Eisner, Sophia Werner, Michael Fraunhofer Institute for Machine Tools and Forming Technology IWU Department of Medical Engineering Dresden Germany

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Monitoring the Evolution of Dimensional Accuracy and Product Properties in Property-Controlled forming Processes

SSRN

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SSRN 2023年

作者： Stebner, Sophie Charlotte Martschin, Juri Arian, Bahman Dietrich, Stefan Feistle, Martin Hütter, Sebastian Lafarge, Rémi Laue, Robert Li, Xinyiang 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 Dortmund University Dortmund Germany Forming and Machining Technology Paderborn University Paderborn Germany Institute for Applied Materials - Material Science Karlsruhe Institute of Technology Karlsruhe Germany Fraunhofer Institute for Casting Composite and Processing Technology Garching Germany Institute of Materials and Joining Technology Otto-von-Guericke University Magdeburg Germany Forming and Machining Processes Technische Universität Dresden Dresden Germany Institute for Machine Tools and Productions Processes Virtual Production Engineering Chemnitz University of Technology Chemnitz Germany Institute of Metal Forming RWTH Aachen University Aachen Germany Institute of Automatic Control RWTH Aachen University Aachen Germany Institute for Production Engineering and Forming Machines Technical University of Darmstadt Darmstadt Germany Institut für Geometrie und Praktische Mathematik RWTH Aachen University Aachen Germany Measurement and Sensor Technology Chemnitz University of Technology Chemnitz Germany Digital Process Engineering Group Institute for Mechanical Process Engineering and Mechanics Karlsruhe Institute of Technology Karlsruhe Germany Materials Test Engineering Dortmund University 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. © 2023, The Authors. All rights reserved.

关键词： Process control

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Does the wall sound different? Variable acoustics in rehearsal rooms using small resonator structures in an acoustic panel 50

Does the wall sound different? Variable acoustics in rehears...

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50th International Congress and Exposition of Noise Control Engineering, INTER-NOISE 2021

作者： Knöfel, Björn van Brummelen, Paula Behrens, Tobias Schirmer, Hartmut Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 Dresden01187 Germany Weißensee Kunsthochschule Berlin Bühringstraße 20 Berlin13086 Germany ADA-Acoustics and Media Consultants GmbH Arkonastr. 45-49 Berlin13189 Germany SCHIRMER GmbH Beratende Ingenieure Radeburger Straße 124 Dresden01109 Germany

ISBN: (纸本)9781732598652

As the name already states, multipurpose rooms are often used from various people for different intentions like meetings or musical practicing. One example are musical rehearsal rooms, where the acoustic specifications have to meet the requirements of musicians playing different instrument groups. To meet the desire for variable acoustics in a rehearsal room, musicians often like to adjust the room to there personal preferences, what is mostly done by adjusting the frequency dependent room decay curve (T60). Hence, a variable acoustic panel has been developed which consists of several small adjustable resonator structures. In a closed state, the structure acts like a resonator. Although Helmholtz resonators are mostly used at low frequencies, the acoustic panel can address acoustic resonance absorption in the mid-frequency range between 500 Hz and 1.500 Hz. The paper highlights especially the dimensioning of the resonators and its measurements in an impedance tube, a reverberation cabin and a reverberation room. Finally, the prototype of the acoustic panel has been analysed in different rehearsal rooms where musicians examine the panel and T60 differences between the open and closed state of the panel were measured. © INTER-NOISE 2021 .All right reserved.

关键词： Reverberation

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Combined laser hardening and laser surface texturing forming tool 1.2379

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Procedia CIRP 2020年 94卷 914-918页

作者： Endalkachew Mekonnen Aragaw Eric Gärtner Andreas Schubert Institute for Machine Tools and Production Processes Chemnitz University of Technology Reichenhainer Str. 70 09107 Germany Fraunhofer Inistitute for Machine tools and Forming Technology IWU Reichenhainer Str. 88 09126 Germany

This paper deals with the tribological performance of forming tool steel 1.2379. Laser hardening and Laser surface texturing are proposed as processes to improve this tribological performance. Hardening influences the surface hardness and wear resistance. While considering the parameter and the specific material, the correlation between heating power and material property is first modelled using FEM of the heat transfer. Based on the modelling result, the realization is performed by nanosecond laser and analyzed by SEM and by comparing the micro –hardness comparison with a reference value. Then textures are integrated into the hardened surface by picosecond laser ablation while focusing on its suitability for smooth dimples and on the examination by pin-on-disk tests for the effect of incorporating textures on the friction performance. Lower friction coefficients between tool and workpiece improve tool durability and product quality as well.

关键词： Laser Hardening (LH) Laser Surface Texturing (LST) Tribology forming tool 1.2379

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