07 Fakultät Konstruktions-, Produktions- und Fahrzeugtechnik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/8

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Publication Type: search.filters.UBSTyp.KonferenzbeitragStart date: 2000End date: 2019

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Now showing 1 - 10 of 39
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    Systematisches Toleranz Design unter Berücksichtigung von Funktions- und Kostenaspekten nach der robusten Zuverlässigkeitsmethode SMAR²T
    (2015) Kemmler, Stefan; Fuchs, Alexander; Leopold, Tobias; Bertsche, Bernd
    Tendenzen für heutige Herausforderungen zur effizienten Produktentwicklung verlagern sich in Richtung von simulativ gestützten virtuellen Herangehensweisen. Hierfür werden in der industriellen Entwicklung komplexer Produkte zunehmend Methoden angewandt, die unter Einsparung von notwendigen Ressourcen umfassende realitätsnahe Ergebnisse liefern. Diese Ergebnisse werden zielgerichtet an die jeweilige Anforderung unter Berücksichtigung deren Robustheit, technische Realisierbarkeit sowie Kosten bezüglich variierender Toleranzeinstellungen, optimiert. Zur Veranschaulichung der methodischen Vorgehensweise zum Gestalten robuster und zuverlässiger Produkte unter Berücksichtigung von Funktions- und Kostenaspekten wird die Vorgehensweise zur Bestimmung eines Kostenmodells im Toleranz Design nach SMAR²T (Systematic Method for Axiomatic Robust Reliability-Testing Method) anhand eines einfachen technischen Systems (Überlastkupplung) diskutiert.
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    Rasselgeräuschprüfstand zur Untersuchung von Fahrzeuggetrieben
    (2011) Fietkau, Peter; Baumann, Axel; Bertsche, Bernd
    In diesem Aufsatz wird der Klapper- und Rasselgeräuschprüfstand am Institut für Maschinenelemente der Universität Stuttgart vorgestellt. Der Prüfstand wurde speziell entwickelt, um die bei Fahrzeuggetrieben auftretenden Losteilgeräusche (Klapper- und Rasselgeräusche) untersuchen zu können. Neben der Beschreibung des allgemeinen Prüfstandsaufbaus wird genauer auf das Regelungskonzept sowie die verwendete Messtechnik eingegangen. Diese zeichnet sich unter anderem durch eine hochgenaue Erfassung der Drehschwingungen aus. Dadurch ist es möglich, Relativbewegungen im Betrieb von im Eingriff stehenden Zahnrädern hochauflösend aufzuzeichnen. Abschließend werden einige exemplarische Messungen dargestellt.
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    Inverse fuzzy arithmetic for the quality assessment of substructured models
    (2015) Iroz, Igor; Carvajal, Sergio; Hanss, Michael; Eberhard, Peter
    The dynamical analysis of complex structures often suffers from large computational efforts, so that the application of substructuring methods has gained increasing importance in the last years. Substructuring enables dividing large finite element models and reducing the resulting multiple bodies, yielding a reduction of, in this case, complex eigenvalue calculation time. This method is used to predict the appearance of friction-induced vibrations such as squeal in brake systems. Since the method is very sensitive to changes in parameter values, uncertainties influencing the results are included and identified. As uncertain parameters, standard coupling elements are considered and modeled by so-called fuzzy numbers, which are particularly well suited to represent epis- temic uncertainties of modeled physical phenomena. The influence of these uncertainties is transferred to undamped and damped eigenfrequencies of a substructured model by means of direct fuzzy analyses. An inverse fuzzy arithmetical approach is applied to identify the uncertain parameters that optimally cover the undamped reference eigenfrequencies of a non-substructured, full model. If a validity criteria is defined, a positive decision in favor of the most adequate model can be performed.
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    On the validation of human body models with a driver-in-the-loop simulator
    (2018) Kempter, Fabian; Fehr, Jörg; Stutzig, Norman; Siebert, Tobias
    For the development of modern integrated safety systems, standard simulation models of anthropometric test devices, often called crash test dummies, are inappropriate for Pre-Crash investigations due to missing activation possibilities, tuned characteristics for one specific accident scenario and high passive stiffness properties. To validate safety concepts getting active prior to the crash new tools like suitable virtual models of human occupants are required. Human Body Models (HBM) provide a higher biofidelity and can be equipped with active muscle elements enabling different muscle activation strategies. To improve the muscle activation strategy and the stiffness properties of active HBMs, validation processes on the basis of low-acceleration experiments are inevitable. In contrast to Post Mortem Human Surrogates only low-severity tests can be performed with real human subjects. This paper presents the workflow of a validation process based on an academic scale Driver-in-the-Loop (DiL) simulator in combination with a synchronized measurement chain consisting of an Optitrack stereo vision and an electromyography detection system.
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    Robust Design Methodology for the development of commercial vehicle braking systems
    (2015) Kemmler, Stefan; Leopold, Tobias; Fricke, Jens; Bertsche, Bernd
    Today’s product requirements demand an ever increasing functionality for the same space and usually the same number of components. Thereby, the quality, reliability and robustness of these products should be preserved or even be increased. This target conflict cannot be solved without compromises. The research community between the Institute of Machine Components (IMA), University of Stuttgart, and the Knorr-Bremse Systeme für Nutzfahrzeuge GmbH is seeking for new solutions for these challenges. The new approaches for designing robust and reliable products are being implemented directly in a current development project of an innovative Air Disc Brake (ADB). With “Systematic Method for Axiomatic Robustness-Testing” (SMART), reliability methods and the basic concept of Robust Design methodology are related to the Taguchi Method. SMART is based on three phases: System, Parameter and Tolerance Design; accordingly, the sample phases of VDA (Association of German Automotives) are used as milestones. In the System Design, SMART focuses on the decreasing complexity according to the functional dependences of the DPs, thus precluding early random failures. In the Parameter Design phase, SMART gives the developer an approach for modeling an adaptive simulation model (SIM-SMART). This model also enables the simulation of random and possible fatigue failures in addition to the nominally robust DPs. In the early stage of product development, reliability predictions are possible. In the iterative Tolerance Design phase, the final tolerance limits for robust and reliable products are defined with consideration of compromises in terms of costs, quality and technical feasibility. With the application of SMART, a design concept of a new generation of an ADB with less complexity is created. The extensive functions for flexible function studies are modeled with the objective of SIM-SMART. Accordingly to this model, parameter studies for determination of the nominal adjustment levels can be performed and their random and fatigue failures modeled. In conclusion, more accurate reliability test strategies are recommended using the definition of tolerance limits. The cost aspect and technical feasibility are also taken into account. So far, SMART has not been added to the iterative Tolerance Design phase. With this paper, the method is not only extended to this phase, but also sufficiently validated. In addition, SMART can predict and analyze random failures. With its three coherent and iterative phases, it is an as yet unpublished and unimplemented approach for designing even more robust and reliable products. Robust Design Methodology and reliability methods are fundamental building blocks for products with high quality requirements. SMART presents an approach to support the designing of robust, reliable, highly functional and innovative ADB.
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    Challenges in the organisational implementation of technology management in companies
    (2014) Olivan, Patrick; Schmitz, Michael; Warschat, Joachim
    Technology management (TM) in bigger companies requires a far more formalised organisational implementation as in smaller companies, because the relevant tasks are realised by employees of different departments and therefore have to be linked organisationally in an effective and efficient way. However a suitable organisational implementation in theory and practice represents a big challenge as various parameter and perspectives need to be considered to select appropriate linking within companies. Therefore this article takes the organisational point of view on TM to illustrate that different essential organisational fields need to be integrated, like the aspects of knowledge, strategy, individuals, processes and culture. Most publications are illustrating only a section of the overall variety of available instruments to realise organisational links. More holistic approaches, on the other hand, are rather described on a quite abstract level that a lack of a practical solution can be determined. For this reason this article overviews common existing approaches of organisational implementation of TM like temporary forms of organisation, processes and roles and arranges them into clusters in order to formalise a summary of methodical deficits. In conclusion, an appropriate method for an organisational implementation for TM in companies which consists of a set of integrated and adjusted approaches is yet missing.
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