@misc{SammMeurer2003, author = {Samm, Doris and Meurer, Marcel}, title = {Die elektrische Leitung und Supraleitung}, year = {2003}, abstract = {Die Lerneinheit stellt in anschaulicher Weise die verschiedenen Modelle der elektrischen Leitung dar und f{\"u}hrt {\"u}ber diese zur Erkl{\"a}rung der Supraleitung. Effekte und Anwendungen der Supraleitung werden in Animationen und Bildern vorgef{\"u}hrt. Ein umfangreiches Glossar erl{\"a}utert wichtige Begriffe.}, subject = {Elektrische Leitung}, language = {de} } @book{Merten2005, author = {Merten, Sabine}, title = {Verbesserung der Ausbildung in der Mikrosystemtechnik - virtuelle Labore bereiten auf die Herstellung realer Drucksensoren vor (2 Fassungen: konvertiert und original}, publisher = {Fachhochschule Aachen}, year = {2005}, abstract = {Die Ausbildung in Hochtechnologien wie beispielsweise der Mikrosystemtechnik ist oft durch einen hohen Grad an Komplexit{\"a}t charakterisiert. Damit verbunden sind hohe Kosten f{\"u}r die Errichtung und den Betrieb der speziellen Laborr{\"a}ume und ihre h{\"a}ufig geringe Verf{\"u}gbarkeit f{\"u}r die Studierenden. Zuk{\"u}nftige Ingenieure sammeln w{\"a}hrend ihrer Ausbildung aus diesen Gr{\"u}nden nur in beschr{\"a}nktem Umfang praktische Erfahrungen. Die Industrie hingegen fordert Personal mit hoher fachlicher Kompetenz, also fundiertem theoretischen Wissen und umfangreichen praktischen Kenntnissen. Dieser Diskrepanz - qualifizierte Ingenieure auf der einen Seite und eine eher theoretisch ausgerichtete Ausbildung auf der anderen Seite - wird mit einem neuen Blended-Learning-Konzept f{\"u}r MST-Technologiepraktika begegnet. Lernende werden {\"u}ber ein virtuelles Labor, das einen echten Reinraum mit realen Anlagen simuliert, intensiv auf reale Laborpraktika vorbereitet. Dabei geht es im virtuellen Labor gleichermaßen um die Vermittlung von Theorie und Praxis. Nur trainierte Teilnehmer mit einer intensiven Vorbereitung sind in der Lage, relativ eigenst{\"a}ndig ein echtes MST-Bauteil innerhalb des anschließenden einw{\"o}chigen Laborkurses zu fertigen. Die Wirksamkeit des Konzeptes und die Steigerung des Lernerfolges durch die kombinierten virtuellen und realen Laborkurse wurden im Rahmen der Dissertation begleitend untersucht. Die Ergebnisse flossen direkt in die Weiterentwicklung der Technologiepraktika ein. Die Konzepte und Erkenntnisse sind zudem sehr interessant f{\"u}r die Entwicklung von Blended-Learning-Angeboten in {\"a}hnlichen oder anderen Fachgebieten sowie f{\"u}r weitere Bildungseinrichtungen. (Die Dissertation liegt hier in 2 Fassungen vor: Die Originalfassung ist nur bei guter Rechnerausstattung und guter Netzanbindung nutzbar, die konvertierte Fassung ist unver{\"a}ndert, allerdings sind Qualit{\"a}tseinbußen beim Ausdruck einiger Grafiken m{\"o}glich)}, subject = {Mikrosystemtechnik}, language = {de} } @article{BaroudWuBohneretal.2003, author = {Baroud, G. and Wu, J.Z. and Bohner, M and Sponagel, Stefan and Steffen, T.}, title = {How to determine the permeability for cement infiltration into osteoporotic cancellous bone}, series = {Medical Engineering \& Physics. 25 (2003), H. 4}, journal = {Medical Engineering \& Physics. 25 (2003), H. 4}, issn = {1350-4533}, pages = {283 -- 288}, year = {2003}, abstract = {Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63\% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice.}, subject = {Osteoporose}, language = {en} } @article{KuehnHaugnerStaatetal.2004, author = {K{\"u}hn, Raoul-Roman and Haugner, Werner and Staat, Manfred and Sponagel, Stefan}, title = {A Two Phase Mixture Model based on Bone Observation}, year = {2004}, abstract = {An optimization method is developed to describe the mechanical behaviour of the human cancellous bone. The method is based on a mixture theory. A careful observation of the behaviour of the bone material leads to the hypothesis that the bone density is controlled by the principal stress trajectories (Wolff's law). The basic idea of the developed method is the coupling of a scalar value via an eigenvalue problem to the principal stress trajectories. On the one hand this theory will permit a prediction of the reaction of the biological bone structure after the implantation of a prosthesis, on the other hand it may be useful in engineering optimization problems. An analytical example shows its efficiency.}, subject = {Knochen}, language = {en} } @article{VuStaat2004, author = {Vu, Duc-Khoi and Staat, Manfred}, title = {An algorithm for shakedown analysis of structure with temperature dependent yield stress}, year = {2004}, abstract = {This work is an attempt to answer the question: How to use convex programming in shakedown analysis of structures made of materials with temperature-dependent properties. Based on recently established shakedown theorems and formulations, a dual relationship between upper and lower bounds of the shakedown limit load is found, an algorithmfor shakedown analysis is proposed. While the original problem is neither convex nor concave, the algorithm presented here has the advantage of employing convex programming tools.}, subject = {Einspielen }, language = {en} } @article{Staat2000, author = {Staat, Manfred}, title = {Direct FEM Limit and Shakedown Analysis with Uncertain Data}, year = {2000}, abstract = {The structural reliability with respect to plastic collapse or to inadaptation is formulated on the basis of the lower bound limit and shakedown theorems. A direct definition of the limit state function is achieved which permits the use of the highly effective first order reliability methods (FORM) is achieved. The theorems are implemented into a general purpose FEM program in a way capable of large-scale analysis. The limit state function and its gradient are obtained from a mathematical optimization problem. This direct approach reduces considerably the necessary knowledge of uncertain technological input data, the computing time, and the numerical error, leading to highly effective and precise reliability analyses.}, subject = {Finite-Elemente-Methode}, language = {en} } @misc{Bellenberg2002, author = {Bellenberg, Markus}, title = {Optimierung einer Roboter-Schweißzelle als Basis eines E-Learning Systems}, year = {2002}, abstract = {Ziel war die technische {\"U}berarbeitung und Optimierung des vorliegenden Prototypen, um eine Basis f{\"u}r ein E-Learning System (Internet unterst{\"u}tztes Lernen) zu schaffen. Zu diesem Zweck wurde das Programm der Robotersteuerung neu erstellt, notwendige mechanische {\"A}nderungen an Roboterequipment und Materialf{\"o}rderung vorgenommen sowie eine neue Internet-Anbindung geschaffen. Wesentliche Ergebnisse der Arbeit sind: • Erzeugen roboterbasierter kreisinterpolierter Bahnschweißn{\"a}hte • Kommunikation des Lernsystems via Internet • Lernorientierte Steuerungssoftware}, subject = {Roboter}, language = {de} } @misc{Balzar2005, author = {Balzar, Christoph Rupert}, title = {Land in land}, year = {2005}, abstract = {[...] Darin suche ich „Zwischenr{\"a}ume" in der digitalen Verschmelzung von Fotos unterschiedlicher Orte und durchleuchte diese neu geschaffenen Landschaften auf ihren Sinn f{\"u}r mich. Anhand der so ge-wonnenen Erkenntnisse belebe ich diese Pl{\"a}tze sp{\"a}ter mit Menschen, Tieren und Fundst{\"u}cken, die mir das Schicksal auf meinen „Walkabouts" durch den australischen Kontinent zugespielt hat und denen ich zu den neu entstandenen Orten passende Bedeutungen beimesse. [...] Neben meinen fl{\"a}chigen, fotografischen und installativen Werken stelle ich auch ein umfassendes Rahmen- und Begleitprogramm zur Ausstellung her, beispielsweise eine CI und eine Homepage.}, subject = {Digitale Photographie}, language = {de} } @article{KaemperPicardBrilletal.2003, author = {K{\"a}mper, Klaus-Peter and Picard, Antoni and Brill, Manfred and Cassel, Detlev and Jentsch, Andreas and Merten, Sabine and Rollwa, Markus}, title = {The Virtual Clean Room - a new tool in teaching MST process technologies}, year = {2003}, abstract = {The Virtual Clean Room - a new tool in teaching MST process technologies University education in high-technology fields like MST is not complete without intensive laboratory sessions. Students cannot fully grasp the complexity and the special problems related to the manufacturing of microsystems without a thorough hands-on experience in a MST clean room.}, subject = {Virtuelle Maschine}, language = {en} } @article{PicardBrillCasseletal.2002, author = {Picard, Antoni and Brill, Manfred and Cassel, Detlev and Jentsch, Andreas and Rollwa, Markus and K{\"a}mper, Klaus-Peter and Merten, Sabine}, title = {Neue Medien f{\"u}r die praktische MST-Ausbildung}, organization = {FH-Kaiserslautern}, year = {2002}, abstract = {Im Studiengang Mikrosystemtechnik des Fachhochschulstandortes Zweibr{\"u}cken werden zwei neue moderne Anlagen f{\"u}r die Herstellung von mikrotechnischen Komponenten in Betrieb genommen: Ein Oxidationsofen f{\"u}r Herstellung d{\"u}nner Oxidschichten auf Silizium-Einkristallen und eine Belichtungsapparatur f{\"u}r die Fotolithografie - das Besondere an diesen Anlagen: Sie existieren nur virtuell, d.h. als Animationen in einer Computerwelt.}, subject = {Mikrosystemtechnik}, language = {de} } @inproceedings{MertenKaemperBrilletal.2003, author = {Merten, Sabine and K{\"a}mper, Klaus-Peter and Brill, Manfred and Picard, Antoni and Cassel, Detlev and Jentsch, Andreas and Rollwa, Markus}, title = {Vom virtuellen Wafer zum realen Drucksensor}, year = {2003}, abstract = {Das Technologiepraktikum „Virtuelle Sensor-Fertigung" ist ein Beispiel f{\"u}r die medientechnische Aufbereitung von Lern- und Lehrmaterial unter didaktischen Gesichtspunkten. Studierende lernen einen Fertigungsprozess mit Hilfe von virtuellen Maschinen kennen, bevor sie die reale Prozesskette im Laborpraktikum im Reinraum durchf{\"u}hren.}, subject = {Virtuelle Maschine}, language = {de} } @inproceedings{MertenKaemperBrilletal.2003, author = {Merten, Sabine and K{\"a}mper, Klaus-Peter and Brill, Manfred and Picard, Antoni and Cassel, Detlev and Jentsch, Andreas and Rollwa, Markus}, title = {Virtuelle Sensor-Fertigung: Hightech mit LabVIEW}, year = {2003}, abstract = {Eine neue Generation von Praktika an Hochschulen w{\"a}chst heran. Moderne Wege beim Verstehen und Erlernen naturwissenschaftlicher Zusammenh{\"a}nge sowie industrieller Fertigungsprozesse sind gefordert. Das Technologiepraktikum „Virtuelle Sensor- Fertigung", entwickelt im Verbundprojekt INGMEDIA an den Fachhochschulen Aachen und Zweibr{\"u}cken, tr{\"a}gt als neuartiges Lern- und Lehrmodul dieser Forderung Rechnung. Die Studierenden lernen einen vollst{\"a}ndigen Fertigungsprozess mit Hilfe von virtuellen, in LabVIEW programmierten Maschinen kennen, bevor sie die reale Prozesskette im Reinraum durchf{\"u}hren.}, subject = {LabVIEW}, language = {de} } @inproceedings{Fabo2004, author = {Fabo, Sabine}, title = {Audio-visual hybrids : between immersion and detachment}, year = {2004}, abstract = {Close interrelations between sound and image are not a mere phenomenon of today's multimedia technology. The idea of the synthesis of different media lies at the core of the concept of the Gesamtkunstwerk in the second half of the 19th century and it can also be traced back to the synaesthesia debate at the beginning of the 20th century [...].}, subject = {Elektronische Kunst}, language = {en} } @article{Fabo2003, author = {Fabo, Sabine}, title = {Das Museum lebt? Der Diskurs der Vernetzung im virtuellen Kunstraum}, series = {Zeitenblicke}, volume = {2(2003)}, journal = {Zeitenblicke}, number = {1}, year = {2003}, abstract = {Kunstwerke sowie ihre Pr{\"a}sentation und Vermittlung werden zunehmend von digitalen Technologien unterst{\"u}tzt. Virtuelle Ausstellungen, Internet-Projekte und komplexe Datenarchive stellen das Kunstwerk in einen medialen Kontext, der weit {\"u}ber das Moment einer technischen Reproduzierbarkeit hinausgeht. Das allgegenw{\"a}rtige Konzept der Vernetzung dynamisiert Kunst, ihre Rezipienten und Ausstellungsorte. Die Beziehungen zwischen diesen Feldern werden mit Hilfe physiologischer Metaphern definiert und visualisiert. Fr{\"u}here Speicher und Archive geraten in einen prozessualen Sog, in dem alles fluktuiert, sich kurzweilig verkn{\"u}pft, aufl{\"o}st und in permanente Dialoge mit seiner Umgebung tritt - das virtuelle Museum ger{\"a}t in aktuellen Standortbestimmungen in die definitorische N{\"a}he des K{\"u}nstlichen Lebens.}, subject = {Elektronische Kunst}, language = {de} } @article{Staat2001, author = {Staat, Manfred}, title = {LISA - a European project for FEM-based limit and shakedown analysis}, year = {2001}, abstract = {The load-carrying capacity or the safety against plastic limit states are the central questions in the design of structures and passive components in the apparatus engineering. A precise answer is most simply given by limit and shakedown analysis. These methods can be based on static and kinematic theorems for lower and upper bound analysis. Both may be formulated as optimization problems for finite element discretizations of structures. The problems of large-scale analysis and the extension towards realistic material modelling will be solved in a European research project. Limit and shakedown analyses are briefly demonstrated with illustrative examples.}, subject = {Einspielen }, language = {en} } @inproceedings{Staat2003, author = {Staat, Manfred}, title = {Design by Analysis of Pressure Components by non-linear Optimization}, year = {2003}, abstract = {This paper presents the direct route to Design by Analysis (DBA) of the new European pressure vessel standard in the language of limit and shakedown analysis (LISA). This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for some examples from the DBA-Manual. One observation from the examples is, that the optimisation approach gives reliable and close lower bound solutions leading to simple and optimised design decision.}, language = {en} } @article{Staat2000, author = {Staat, Manfred}, title = {Basis Reduction for the Shakedown Problem for Bounded Kinematic Hardening Material}, year = {2000}, abstract = {Limit and shakedown analysis are effective methods for assessing the load carrying capacity of a given structure. The elasto-plastic behavior of the structure subjected to loads varying in a given load domain is characterized by the shakedown load factor, defined as the maximum factor which satisfies the sufficient conditions stated in the corresponding static shakedown theorem. The finite element dicretization of the problem may lead to very large convex optimization. For the effective solution a basis reduction method has been developed that makes use of the special problem structure for perfectly plastic material. The paper proposes a modified basis reduction method for direct application to the two-surface plasticity model of bounded kinematic hardening material. The considered numerical examples show an enlargement of the load carrying capacity due to bounded hardening.}, subject = {Finite-Elemente-Methode}, language = {en} } @article{Staat2003, author = {Staat, Manfred}, title = {Shakedown and ratchetting under tension-torsion loadings: analysis and experiments}, year = {2003}, abstract = {Structural design analyses are conducted with the aim of verifying the exclusion of ratchetting. To this end it is important to make a clear distinction between the shakedown range and the ratchetting range. The performed experiment comprised a hollow tension specimen which was subjected to alternating axial forces, superimposed with constant moments. First, a series of uniaxial tests has been carried out in order to calibrate a bounded kinematic hardening rule. The load parameters have been selected on the basis of previous shakedown analyses with the PERMAS code using a kinematic hardening material model. It is shown that this shakedown analysis gives reasonable agreement between the experimental and the numerical results. A linear and a nonlinear kinematic hardening model of two-surface plasticity are compared in material shakedown analysis.}, subject = {Einspielen }, language = {en} } @article{Staat2005, author = {Staat, Manfred}, title = {Direct finite element route for design-by-analysis of pressure components}, year = {2005}, abstract = {In the new European standard for unfired pressure vessels, EN 13445-3, there are two approaches for carrying out a Design-by-Analysis that cover both the stress categorization method (Annex C) and the direct route method (Annex B) for a check against global plastic deformation and against progressive plastic deformation. This paper presents the direct route in the language of limit and shakedown analysis. This approach leads to an optimization problem. Its solution with Finite Element Analysis is demonstrated for mechanical and thermal actions. One observation from the examples is that the so-called 3f (3Sm) criterion fails to be a reliable check against progressive plastic deformation. Precise conditions are given, which greatly restrict the applicability of the 3f criterion.}, subject = {Einspielen }, language = {en} } @article{Staat2005, author = {Staat, Manfred}, title = {Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels}, year = {2005}, abstract = {Limit loads can be calculated with the finite element method (FEM) for any component, defect geometry, and loading. FEM suggests that published long crack limit formulae for axial defects under-estimate the burst pressure for internal surface defects in thick pipes while limit loads are not conservative for deep cracks and for pressure loaded crack-faces. Very deep cracks have a residual strength, which is modelled by a global collapse load. These observations are combined to derive new analytical local and global collapse loads. The global collapse loads are close to FEM limit analyses for all crack dimensions.}, subject = {Finite-Elemente-Methode}, language = {en} }