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Zur Herstellung von CFK-Bauteilen sind Laminierformen erforderlich. In der Kleinstserienfertigung und im Prototypenbau müssen demzufolge die Werkzeugkosten auf geringe Stückzahlen umgelegt werden, was eine erhebliche Verteuerung der Stückkosten bedeutet. Darüber hinaus sind ebenfalls die Durchlaufzeiten in der Fertigung entsprechend lang, bis die CFK-Teile abgeformt werden können.
Um Fertigungskosten einzusparen und um vorrangig diesen Fertigungs-prozess zu beschleunigen, wurden Laminierformen aus Kunststoff mit einem Rapid Prototyping Prozess nach dem Fused Depo-sition Modeling Verfahren aufgebaut. Des Weiteren wurde untersucht, wie sich bei den Kunststoffformteilen die Oberfläche veredeln lässt, damit die herstellbedingten Schichtstufen egalisiert werden können.
Abschließend wurde dieser Rapid Shaping Prozess an zwei ausgewählten CFK-Bauteilen verifiziert.
Mit einem 3D-CAD System wurde dem Konstrukteur ein Werkzeug an die Hand gegeben, mit dem er schneller und zuverlässiger seine Konstruktionen am Rechner ausführen kann, als dies über Jahrhunderte hinweg mit dem Reißbrett möglich war. Aufbauend darauf können aus den räumlichen CAD-Daten über eine Rapid Prototyping Anlage schnell Bauteile für Anschauungs- oder Funktions-muster hergestellt werden. Umgekehrt hierzu ist es möglich, reale Objekte mit einem 3D-Scanner zu erfassen, um diese dann in die virtuelle Rechnerwelt zurück-zuführen. Schließlich können die CAD Konstruktionen an einer virtuellen Wand als Modelle realistischer als am Monitor betrachtet werden. Anhand ausgesuchter Fallbeispiele soll gezeigt werden, wie mit diesen 3D-Werkzeugen die Produktentwicklungs-prozesskette beschleunigt, die Produktkosten gesenkt und die Qualität gesteigert werden können.
Based on the full state-controller theory, a new ob-server-controller for MAGLEV vehicles considering the guideway elasticity was proposed in early publi-cations in Germany and now realized in practice in China. It is expected to eliminate the phenomenon of the vehicle-guideway coupling vibration caused by the hypothesis of a rigid guideway, which usually happens in the current high-speed MAGLEV line, and reduce the over dependence of system stability on the guideway properties. A test rig for the elastic guideway levitation system was founded and the effectiveness of the new observer-controller was verified.
Die Anregung der im Nachfolgenden dargestellten Untersuchung verdanken die Verfasser Herrn Prof. Dr.-Ing. Dieter Tremmel.
Das vorliegende Werk kann als Fortsetzung der Arbeiten [1] und [2] angesehen werden. Es handelt sich um die geometrische Synthese von Verzahnungen mit windschiefen Achsen, die aus einem schräg- und einem geradverzahnten Zahnrad be-stehen. In der umfangreichen Literatur, die der Geometrie der Verzahnungen gewidmet ist (vgl. z.B. [3]-[14]), ist für diesen Fall kein einziges konkretes Beispiel zu finden.
This paper discusses the possibilities of IPtechnologies for information protection. An analysis of modern information protection Soft-Cores which support symmetric block ciphers is given. Development perspectives of the Soft-Cores are described. The DES Algorithm and the variations of the architecture of the DES Soft-Core models are considered, their analysis provided and they are compared with some existing DES Soft-Cores on the world market. Two architectures - iterative and pipelined - are identified. Twenty six variations of the DES Soft-Core are proposed and a comparative analysis of their architecture is given. The proposed DES Soft-Cores support all of the discussed functional possibilities. Thus a high performance is achieved, the equipment volume for their realization is lowered and they can be used effectively in a wide spectrum of the application fields.
This paper compares the Federal Reserve System and the Eurosystem in four aspects. These are the institutional level, the monetary policy instruments, the operational framework and the monetary policy strategy applied. It highlights the similarities, the differences as well as the efficiency of the different settings.
This paper is dealing with teaching and leadership. As a contribution to the current discussion of the position and the role of professors at universities in Europe, a phenomenological-humanistic approach will be outlined (as part one). This approach has been applied to the feedback data by 3302 students from Germany and other countries evaluating their lectures of one professor from 1969 to 2000. The survey data were collected by the technique named "Semantic Differential" developed by Osgood and elaborated by Hofstätter. Interestingly, a remarkable pattern constituted by students´ attributions to their learning processes with the author has emerged from the late sixties to the actual millennium. Part two of this paper reflects statements of colleagues and students from all parts of Germany and abroad, too. In addition, a frame-work of socalled pedagogical leads as an underlying principle will be outlined. And the parts three and four offer typical examples of this approach to teaching. Part three presents a record of an old but still actual excursion in synectics titled "How our students of 1974 saw our world of 2000" elaborated by students of engineering and economics enrolled 1974. Finally, the part four comes with an actual example of our examinations for students of engineering enrolled in the compulsory / optional subject "Personality and creativity training".
Knowledge of the features and qualities of a machine element are essential foundations for its successful operation. High grade materials, more accurate calculation methods and modern manufacturing processes lead to continuous design and performance improvements and hence increased power within minimised spatial requirements. INA cylindrical roller bearings, series SL 1923.., ZSL 1923.. and LSL 1923.. follow this trend and due to their high performance characteristics and low physical volume they have obtained a firm place as high performance machine elements. Essential characteristics of radial cylindrical roller bearings are their behaviour regarding kinematics, noise, vibration, dynamic frictional torque, cage speed, speed of a rolling element, slip etc. The paper gives details of the kinematic behaviour concerning the relationship between the roller set speed or the cage speed and the speed of a rolling element in connection with the occurrence of smearing. This kind of damage occurs during the running in stage of a machine and is becoming very important because of the enormous costs which are caused by down time and lost production.
Online Measurement of mechanical parameters by using CAM (Computer Aided Measurement) is a new advanced technique in the field of measurement. Taking special measurement software DASYLab as an example, this paper describes the basic principles and unique advantages of this technique. The application of CAM is explained through an example of measurements of temperature, flow rate and pressure.
The dynamic behaviour of a railway bogie has been investigated by using a mathematical model, a space state equation, for simulation with a computer. The comparison of a damped with a undamped bogie demonstrated that the driving stability at high speeds can be uprated after the installation of dampers acting in driving direction and allaround the vertical rotation axis of the bogie. The maximum speed of the damped bogie has amounted t0 76 m/s.