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Gathering of Process Data through Numerical Simulation for the Application of machine Learning Prognosis Algorithms

Procedia Manufacturing 2020年 47卷 608-614页

作者： Mathias Jäckel Tobias Falk Julius Georgi Welf-Guntram Drossel Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 Dresden 01187 Germany

In recent years, FEA simulation of forming processes has increasingly developed as a good alternative to complex experimental work in the determination of process parameters and product properties. However, detailed material data (e.g. flow curves) are necessary for the execution of FEA simulations, which are often not available to manufacturers and users in the early stages of the product development. In this paper, a method is shown by which application it is possible, that only on the basis the general mechanical properties (e.g. tensile strength, sheet thickness) and the use of data-based prognosis models of supervised machine learning to predict directly a result regarding suitable process parameters as well as expected forming result properties. Thereby an extensive technological database was generated for the joining by forming process self-pierce riveting (SPR) by means of numerical simulation. Subsequently, different learning algorithms are trained using these numerical data and their prediction quality is compared.

关键词： machine Learning forming Simulation Self-pierce riveting

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Development of a New Self-flaring Rivet Geometry Using Finite Element Method and Design of Experiments

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Procedia Manufacturing 2020年 47卷 383-388页

作者： Christian Kraus Tobias Falk Reinhard Mauermann Welf-Guntram Drossel Fraunhofer Institute for Machine Tools and Forming Technology IWU Nöthnitzer Straße 44 Dresden 01187 Germany

The paper presents a new joining process for mixed joints of metallic and non-metallic materials. The process bases on a self-flaring rivet, which lances the joining partners and, due to its geometry, produces an interlock. In contrast to conventional self-piercing processes such as self-pierce riveting with semi-tubular rivets (SPR), the new process does not require a special shaped die as counter tool. The development of the rivet geometry is carried out with the aid of FEM analyses in SFTC Deform-3D. Design of experiments (DoE) is used to find a suitable rivet geometry that is stable enough to lance high-strength steel. However, the rivet element must be flaring to produce an interlock. The challenges and solution approaches associated with the modelling of material damage and separation in the three-dimensional calculation models of the riveting process are presented. The consideration of macromechanical and geometrical criteria for element deletion is important in order to obtain robust models with useful results. The validation of the model is done by comparing the simulation results with experimental data.

关键词： Mechanical Joining Finite Element Method Design of Experiments

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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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Impact of Cyber-physically enhanced manufacturing on the product requirement documentation in high-tech applications

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Procedia CIRP 2021年 102卷 210-215页

作者： Albrecht Hänel André Seidel Carl Willy Mehling Alexander Dementyev Karol Kozak Rudi Seidel Uwe Teicher Arvid Hellmich Welf-Guntram Drossel Steffen Ihlenfeldt Fraunhofer Institute for Machine Tools and Forming Technology IWU Dresden 01187 Germany Technische Universität Dresden Center for Evidence-based Healthcare Dresden 01307 Germany Technische Universität Chemnitz Institute for Machine Tools and Production Processes Chemnitz 09126 Germany Technische Universität Dresden Institute of Mechatronic Engineering Dresden 01062 Germany

Conventional machining of high-tech parts and components is often associated with complex processes, long lead times and small to medium batch sizes. Obviously, there is great interest to shorten process development periods and increase process reliability. The transformation of conventional machines into cyber-physical production systems (CPPS) promises significant improvements here. In fact, CPPS allows real-time data acquisition and processing, enabling to target integrated process improvement and quality assurance. In the present work, a methodical procedure for structured data aggregation is introduced for a Cyber-physical enhanced machining process while being explained from a high-tech application point of view. This includes data generation, extraction, transfer and storage, data-consolidation, linkage, visualization and interpretation. Finally, the paper illustrates these aspects in terms of the effects on the “digital product requirements” in order to achieve the presented “analytics-ready” data model using the example of a high-tech application.

关键词： Digital Manufacturing System Modelling Process control Cyber-physical production

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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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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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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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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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