TY - JOUR A1 - Sponagel, Stefan A1 - Becker, E. T1 - Reibungsfreie, ebene Diffusorströmung mit beliebigem Einlaufprofil. E. Becker, S. Sponagel JF - Zeitschrift für angewandte Mathematik und Mechanik: ZAMM. 64 (1984) Y1 - 1984 SN - 0044-2267 N1 - weitere ISSN: 0946-8463 SP - T174 EP - T177 ER - TY - PAT A1 - Sponagel, Stefan A1 - Graf, Günter A1 - Groß, Heinz T1 - Method for manufacturing a sealing ring : United States Patent 4,861,536 ; date of patent: Aug. 12, 1989 / assignee: Firma Carl Freudenberg. Inventors: Gunter Graf ; Heinz Gross ; Stefan Sponagel Y1 - 1989 N1 - Barcode: US004861536A ; Volltext über Datenbank: http://www.google.com/patents PB - [United States Patent and Trademark Office] CY - [Alexandria, VA] ER - TY - PAT A1 - Sponagel, Stefan A1 - Graf, Günter A1 - Groß, Heinz T1 - Method for the manufacture of a sealing ring with a sealing lip having hydrodynamically acting return elements : United States Patent 4,850,097 ; date of patent: Jul. 25, 1989 / assignee: Firma Carl Freudenberg. Inventors: Gunter Graf ; Heinz Gross ; Stefan Sponagel Y1 - 1989 N1 - Barcode: US004850097A ; Volltext über Datenbank: http://www.google.com/patents PB - [United States Patent and Trademark Office] CY - [Alexandria, VA] ER - TY - PAT A1 - Sponagel, Stefan A1 - Graf, Günter A1 - Groß, Heinz T1 - Verfahren zur Herstellung eines Dichtringes : Patentschrift DE3621242C1 ; Veröffentlichungstag der Patenterteilung : 25.06.1987 / Anmelder: Fa. Carl Freudenberg. Erfinder: Günter Graf ; Heinz Groß ; Stefan Sponagel Y1 - 1987 N1 - Volltext über Datenbank: http://register.dpma.de/DPMAregister/pat/einsteiger PB - Deutsches Patent- und Markenamt CY - München ER - TY - JOUR A1 - Sponagel, Stefan A1 - Groling, G. T1 - Eine Bemerkung zum Beweis des π Theorems. G. Groling, S. Sponagel JF - Zeitschrift für angewandte Mathematik und Mechanik: ZAMM. 63 (1983) Y1 - 1983 SN - 0044-2267 N1 - weitere ISSN: 0946-8463 SP - T258 EP - T259 ER - TY - JOUR A1 - Sponagel, Stefan A1 - Kilthau, G. A1 - Spies, K. H. T1 - Sealing mechanism of lip seals JF - Eleventh 11th International Conference on Fluid Sealing : proceedings of the 11th Internat. Conference on Fluid Sealing, held at Cannes, France 8 - 10 April, 1987 / organised and sponsored by BHRA, the Fluid Engineering Centre. Ed. B. S. Nau Y1 - 1987 SN - 3-540-51383-3 N1 - International Conference on Fluid Sealing <11, 1987, Cannes> SP - 748 EP - 772 PB - Elsevier CY - London ER - TY - JOUR A1 - Sponagel, Stefan A1 - Lutz, T. T1 - Aggregatelager JF - Kautschuk Gummi Kunststoffe. 43 (1990), H. 5 Y1 - 1990 SN - 0022-9520 SP - 397 EP - 406 ER - TY - JOUR A1 - Sponagel, Stefan A1 - Lutz, Th. T1 - Ein Beitrag zur Bestimmung der Haertewerte von Elastomeren JF - Kautschuk Gummi Kunststoffe. 43 (1990), H. 10 Y1 - 1990 SN - 0022-9520 SP - 861 EP - 865 ER - TY - PAT A1 - Sponagel, Stefan A1 - Masberg, Mariane A1 - Hartmann, Jochen T1 - Kraftfahrzeugkühlwasserpumpe : Offenlegungsschrift DE19803739A1 ; Veröffentlichungstag im Patentblatt: 12.08.1999 Y1 - 1999 PB - Deutsches Patent- und Markenamt CY - München ER - TY - JOUR A1 - Sponagel, Stefan A1 - Müller, H. T1 - Exakte instationäre Lösungen der Navier-Stokes-Gleichung. H. Müller, S. Sponagel JF - Zeitschrift für angewandte Mathematik und Mechanik: ZAMM. 63 (1983) Y1 - 1983 SN - 0044-2267 N1 - weitere ISSN: 0946-8463 SP - T273 EP - T275 ER - TY - JOUR A1 - Sponagel, Stefan A1 - Spaltofski, R. T1 - Hochmolekulare Zusätze verbessern die Leichtlaufeigenschaft und die Tragfähigkeit von Schmierfilmen / Sponagel, S. ; Spaltofski, R. JF - Mineralöltechnik. 32 (1987), H. 3 Y1 - 1987 SN - 0341-1893 SP - 28 S. ER - TY - JOUR A1 - Sponagel, Stefan A1 - Spaltofski, R. A1 - Steinhilper, W. T1 - Hochmolekulare Additive für die Gleitlagerschmierung. Spaltofski, R.; Sponagel, S.; Steinhilper, W. JF - Tribologie und Schmierungstechnik. 35 (1988), H. 5 Y1 - 1988 SN - 0036-6218 SP - 236 EP - 241 ER - TY - JOUR A1 - Sponagel, Stefan A1 - Unger, J. T1 - Organisation und Strukturierung technischer Messungen JF - Werkstattstechnik. 88 (1998), H. 5 Y1 - 1998 SN - 1436-5006 SP - 223 EP - 226 ER - TY - JOUR A1 - Sponagel, Stefan A1 - Unger, J. A1 - Spies, K. H. T1 - Härtebegriff im Zusammenhang mit Vernetzung, Bruchdehnung und Dauerfestigkeit eines Elastomers JF - Kautschuk Gummi Kunststoffe. 56 (2003), H. 11 Y1 - 2003 SN - 0948-3276 SP - 608 EP - 613 ER - TY - PAT A1 - Sponagel, Stefan A1 - Wachowitz, Waldemar T1 - Shaft seal : United States Patent 5,143,385 ; date of patent: Sep. 1, 1992 / assignee: Firma Carl Freudenberg Y1 - 1992 N1 - Barcode: US005143385A ; Volltext über Datenbank: http://www.google.com/patents PB - [United States Patent and Trademark Office] CY - [Alexandria, VA] ER - TY - PAT A1 - Sponagel, Stefan A1 - Wachowitz, Waldemar T1 - Wellendichtung : Offenlegungsschrift DE3830706A1 ; Veröffentlichungstag im Patentblatt: 22.03.1990 / Anmelder: Fa. Carl Freudenberg Y1 - 1990 PB - Deutsches Patent- und Markenamt CY - München ER - TY - BOOK A1 - Sponagel, Stefan A1 - Wachowitz, Waldemar T1 - Wellendichtung : Europäische Patentschrift DE3621242C1 ; Veröffentlichungstag der Patentschrift : 06.06.1993 / Anmelder: Fa. Carl Freudenberg Y1 - 1993 N1 - Volltext über Datenbank: http://publikationen.dpma.de/ PB - Europäisches Patentamt CY - [München u.a.] ER - TY - CHAP A1 - Spurmann, Jörn A1 - Ohndorf, Andreas A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Löb, Horst A1 - Schartner, Karl-Heinz T1 - Interplanetary trajectory optimization for a sep mission to Saturn T2 - 60th International Astronautical Congress 2009 N2 - The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general. KW - Spacecraft KW - Reusable Rocket Engines KW - Hybrid Propellants Y1 - 2009 SN - 9781615679089 N1 - 60th International Astronautical Congress 2009 (IAC 2009) Held 12-16 October 2009, Daejeon, Republic of Korea. SP - 5234 EP - 5248 ER - TY - JOUR A1 - Späte, Frank A1 - Faber, Christian A1 - Schwarzer, Klemens A1 - Hartz, Thomas T1 - Comparison of solar hot water systems in solar settlements - decentralized or centralized systems? JF - Proceedings / organised by: ISES Europe ... [Ed.: Deutsche Gesellschaft für Sonnenenergie e.V. - DGS, Munich ; PSE GmbH - Forschung Entwicklung Marketing, Freiburg]. - Vol. 1 Y1 - 2004 SN - 3-9809656-1-9 N1 - EuroSun <5, 2004, Freiburg, Breisgau> ; Internationales Sonnenforum <14, 2004, Freiburg, Breisgau> ; Deutsche Gesellschaft für Sonnenenergie SP - 1-666-1-671 PB - PSE CY - Freiburg [Breisgau] ER - TY - CHAP A1 - Späte, Frank A1 - Hafner, B. A1 - Schwarzer, Klemens T1 - A system for solar process heat for decentralized applications in developing countries T2 - ISES 1999 Solar World Congress, Jerusalem, Israel, July 4-9, 1999 : conference proceedings / ed. Gershon Grossman. Vol. 3 Y1 - 2000 SN - 0-080-043895-4 SP - 236 EP - 291 PB - Elsevier CY - Oxford ER - TY - CHAP A1 - Späte, Frank A1 - Hubrich, Jörg A1 - Keip, Wolfgang A1 - Meliß, Michael T1 - Der Solar-Campus Jülich - Stand der Arbeiten T2 - Deutschlands Weg in eine solare Zukunft : Tagungsband; 26. - 30. Juni 1998 Fachhochschule Köln / 11. Internationales Sonnenforum Y1 - 1998 SP - 666 EP - 672 PB - Solar Promotion CY - München ER - TY - CHAP A1 - Späte, Frank A1 - Wollscheid, Georg A1 - Meliß, Michael T1 - Erdreichwärmetauscher im Solar-Campus Jülich T2 - Deutschlands Weg in eine solare Zukunft : Tagungsband; 26. - 30. Juni 1998 Fachhochschule Köln / 11. Internationales Sonnenforum Y1 - 1998 SP - 591 EP - 598 PB - Solar Promotion CY - München ER - TY - JOUR A1 - Srivastava, A. A1 - Chahar, V. A1 - Sharma, V. A1 - Sun, Y. A1 - Bol, R. A1 - Knolle, F. A1 - Schnug, E. A1 - Hoyler, Friedrich A1 - Naskar, N. A1 - Lahiri, S. A1 - Patnaik, R. T1 - Study of uranium toxicity using low-background gamma-ray spectrometry JF - Journal of Radioanalytical and Nuclear Chemistry Y1 - 2017 U6 - https://doi.org/10.1007/s10967-017-5466-9 SN - 1588-2780 IS - Online first SP - 1 EP - 7 PB - Springer CY - Berlin ER - TY - JOUR A1 - Srivastava, A. A1 - Lahiri, S. A1 - Maiti, M. A1 - Knolle, F. A1 - Hoyler, Friedrich A1 - Scherer, Ulrich W. A1 - Schnug, E. W. T1 - Study of naturally occurring radioactive material (NORM) in top soil of Punjab State from the North Western part of India JF - Journal of Radioanalytical and Nuclear Chemistry Y1 - 2014 U6 - https://doi.org/0.1007/s10967-014-3450-1 SN - 1588-2780 (E-Journal); 0022-4081 (Print); 0134-0719 (Print); 0236-5731 (Print); 1417-2097 (Print) VL - 2014 IS - 302 SP - 1049 EP - 1052 PB - Springer Nature CY - Basel ER - TY - JOUR A1 - Srivastava, A. A1 - Singh, V. A1 - Aggarwal, P. A1 - Schneeweiss, F. A1 - Scherer, Ulrich W. A1 - Friedrich, W. T1 - Optical studies of insulating polymers for radiation dose monitoring JF - Indian Journal of Pure & Applied Physics Y1 - 2010 SN - 0019-5596 N1 - Special Issue: SI VL - 48 IS - 11 SP - 782 EP - 786 ER - TY - CHAP A1 - Srivastava, Alok A1 - Knolle, F. A1 - Schnug, E. A1 - Scherer, Ulrich W. T1 - Study of Trace Elements in Water Bodies of the Harz Mts. Region, Germany using Total Reflection X Ray Fluorescence (TXRF) T2 - DAE-BRNS 12th National Symposium on Nuclear and Radiochemistry NUCAR 2015, Feb. 9-13, Mumbai, India, Mumbai, India; 02/2015 Y1 - 2015 SP - 355 EP - 356 ER - TY - CHAP A1 - Srivastava, Alok A1 - Knolle, Friedhart A1 - Hoyler, Friedrich A1 - Scherer, Ulrich W. A1 - Schnug, Ewald T1 - Uranium Toxicity in the State of Punjab in North-Western India T2 - Management of Natural Resources in a Changing Environment N2 - Lately there has been an increasing concern about uranium toxicity in some districts of Punjab State located in the North Western part of India after the publication of a report (Blaurock-Busch et al. 2010) which showed that the concentration of uranium in hair and urine of children suffering from physical deformities, neurological and mental disorder from Malwa region (Fig. 1) of Punjab State was manifold higher than the reference ranges. A train which connects the affected region with the nearby city of Bikaner which has a Cancer Hospital has been nicknamed as Cancer Express due to the frenzy generated on account of uranium related toxicity. Y1 - 2015 SN - 978-3-319-12559-6 U6 - https://doi.org/10.1007/978-3-319-12559-6_21 SP - 271 EP - 275 PB - Springer CY - Cham ER - TY - CHAP A1 - Srivastava, Alok A1 - Singh, Virendra A1 - Dhand, Chetna A1 - Kaur, Manindar A1 - Singh, Tejvir A1 - Witte, Katrin A1 - Scherer, Ulrich W. T1 - Study of swift heavy ion modified conduction polymer composites for application as gas sensor N2 - A polyaniline-based conducting composite was prepared by oxidative polymerisation of aniline in a polyvinylchloride (PVC) matrix. The coherent free standing thin films of the composite were prepared by a solution casting method. The polyvinyl chloride-polyaniline composites exposed to 120 MeV ions of silicon with total ion fluence ranging from 1011 to 1013 ions/cm2, were observed to be more sensitive towards ammonia gas than the unirradiated composite. The response time of the irradiated composites was observed to be comparably shorter. We report for the first time the application of swift heavy ion modified insulating polymer conducting polymer (IPCP) composites for sensing of ammonia gas. KW - Biosensor KW - Conducing polymer KW - ammonia gas sensors KW - swift heavy ions KW - polymer composites Y1 - 2006 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:hbz:a96-opus-1345 ER - TY - JOUR A1 - Srnanek, R. A1 - Geurts, J. A1 - Lentze, M. A1 - Irmer, G. A1 - Donoval, D. A1 - Brdecka, P. A1 - Kordos, P. A1 - Förster, Arnold A1 - Sciana, B. A1 - Radziewicz, D. A1 - Tlaczala, M. T1 - Study of d-doped GaAs layers by micro-Raman spectroscopy on bevelled samples JF - Applied surface science . 230 (2004), H. 1 -4 Y1 - 2004 SN - 0169-4332 N1 - ISSN der E-Ausg.: 0169-4332 SP - 379 EP - 385 ER - TY - JOUR A1 - Staat, Manfred T1 - Failure probabilities of the primary circuit pressure boundary of an HTR-Module for process heat generation under accident conditions for different failure modes JF - Nuclear Engineering and Design. 144 (1993), H. 1 Y1 - 1993 SN - 0029-5493 SP - 53 EP - 67 ER - TY - JOUR A1 - Staat, Manfred T1 - Plastic collapse analysis of longitudinally flawed pipes and vessels JF - Nuclear Engineering and Design. 234 (2004), H. 1-3 Y1 - 2004 SN - 0029-5493 SP - 25 EP - 43 ER - TY - JOUR A1 - Staat, Manfred T1 - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels JF - International Journal of Pressure Vessels and Piping. 82 (2005), H. 3 Y1 - 2005 SN - 0308-0161 SP - 217 EP - 225 ER - TY - JOUR A1 - Staat, Manfred T1 - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels N2 - 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. KW - Finite-Elemente-Methode KW - Grenzwertberechnung KW - Axialbelastung KW - FEM KW - Grenzwertberechnung KW - Axialbelastung KW - Traglastanalyse KW - Limit analysis KW - Global and local collapse KW - Axially cracked pipe KW - Pressure loaded crack-face Y1 - 2005 ER - TY - JOUR A1 - Staat, Manfred T1 - Plastic collapse analysis of longitudinally flawed pipes and vessels N2 - Improved collapse loads of thick-walled, crack containing pipes and vessels are suggested. Very deep cracks have a residual strength which is better modelled by a global limit load. In all burst tests, the ductility of pressure vessel steels was sufficiently high whereby the burst pressure could be predicted by limit analysis with no need to apply fracture mechanics. The relative prognosis error increases however, for long and deep defects due to uncertainties of geometry and strength data. KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohr KW - Rohrbruch KW - Druckbehälter KW - Stahl KW - Druckbelastung KW - Druckbeanspruchung KW - Rohrbruch KW - Fehlerstellen KW - pipes KW - vessels KW - load limit KW - burst tests KW - burst pressure KW - flaw Y1 - 2004 ER - TY - CHAP A1 - Staat, Manfred T1 - Design by Analysis of Pressure Components by non-linear Optimization N2 - 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. KW - Analytischer Zulaessigkeitsnachweis KW - FEM KW - Einspiel-Analyse KW - design-by-analysis KW - finite element analysis KW - limit and shakedown analysis Y1 - 2003 ER - TY - JOUR A1 - Staat, Manfred T1 - Shakedown and ratchetting under tension-torsion loadings: analysis and experiments N2 - 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. KW - Einspielen KW - Einspielen KW - Ratchetting KW - Zug-Druck Belastung KW - shakedown KW - ratchetting KW - tension–torsion loading Y1 - 2003 ER - TY - JOUR A1 - Staat, Manfred T1 - Direct finite element route for design-by-analysis of pressure components N2 - 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. KW - Einspielen KW - Plastizität KW - Deformation KW - Analytischer Zulaessigkeitsnachweis KW - Einspiel-Analyse KW - fortschreitende plastische Deformation KW - alternierend Verformbarkeit KW - Einspiel-Kriterium KW - Design-by-analysis KW - Shakedown analysis KW - Progressive plastic deformation KW - Alternating plasticity KW - Shakedown criterion Y1 - 2005 ER - TY - THES A1 - Staat, Manfred T1 - Nichtlineare Wellen in elastischen Scheiben Y1 - 1987 N1 - Aachen, Techn. Hochsch., Diss., 1987 CY - Aachen ER - TY - JOUR A1 - Staat, Manfred T1 - Reliability of the Primary Circuit Pressure Boundary of an HTR-Module under Accident Conditions JF - Safety and reliability assessment : an integral approach ; ESREL'93 ; proceedings of the European Safety and Reliability Conference, Munich, Germany, May 10th - 12th 1993 / Kafka, P. [ed] Y1 - 1993 SN - 0-444-81561-9 SP - 331 EP - 342 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Staat, Manfred T1 - Some Achievements of the European Project LISA for FEM Based Limit and Shakedown Analysis JF - Computational mechanics : developments and applications, 2002 : presented at the 2002 ASME Pressure Vessels and Piping Conference, Vancouver, British Columbia, Canada, August 5 - 9. / Badie, N. [ed] Y1 - 2002 SN - 0791846520 N1 - Serie PVP ; vol. 441. SP - 177 EP - 185 PB - American Society of Mechanical Engineers CY - New York ER - TY - GEN A1 - Staat, Manfred T1 - Technische Mechanik. Vorlesungsmitschrift. Korrigierter Nachdr. der 3. Aufl. N2 - Überarbeitete, korrigierte und ergänzte Version einer Vorlesungsmitschrift von Sebastian Krämer. 172 S. Inhaltsverzeichnis 0 Einführung in die Mechanik 1 Statik starrer Körper 2 Elastostatik (Festigkeitslehre) 3 Kinematik 4 Kinetik Literatur KW - Technische Mechanik Y1 - 2006 ER - TY - GEN A1 - Staat, Manfred T1 - Engineering Mechanics. Lecture Notes. 2nd edition, translation of the 3rd corrected and extended German edition of "Technische Mechanik" N2 - English translation of the corrected lectures notes of Sebastian Krämer. Contents 0 Introduction to Mechanics 1 Statics of Rigid Bodies 2 Elastostatics (Strength of Materials) 3 Kinematics 4 Kinetics Literature KW - Technische Mechanik KW - Mechanics KW - Statics KW - Elastostatics KW - Kinematics KW - Kinetics Y1 - 2006 ER - TY - CHAP A1 - Staat, Manfred T1 - Problems and chances for probabilistic fracture mechanics in the analysis of steel pressure boundary reliability. - Überarb. Ausg. N2 - In: Technical feasibility and reliability of passive safety systems for nuclear power plants. Proceedings of an Advisory Group Meeting held in Jülich, 21-24 November 1994. - Vienna , 1996. - Seite: 43 - 55 IAEA-TECDOC-920 Abstract: It is shown that the difficulty for probabilistic fracture mechanics (PFM) is the general problem of the high reliability of a small population. There is no way around the problem as yet. Therefore what PFM can contribute to the reliability of steel pressure boundaries is demon­strated with the example of a typical reactor pressure vessel and critically discussed. Although no method is distinguishable that could give exact failure probabilities, PFM has several addi­tional chances. Upper limits for failure probability may be obtained together with trends for design and operating conditions. Further, PFM can identify the most sensitive parameters, improved control of which would increase reliability. Thus PFM should play a vital role in the analysis of steel pressure boundaries despite all shortcomings. KW - Bruchmechanik KW - probabilistic fracture mechanics KW - PFM Y1 - 2006 ER - TY - JOUR A1 - Staat, Manfred T1 - Cyclic plastic deformation tests to verify FEM-based shakedown analyses N2 - Fatigue analyses are conducted with the aim of verifying that thermal ratcheting is limited. To this end it is important to make a clear distintion between the shakedown range and the ratcheting range (continuing deformation). As part of an EU-supported research project, experiments were carried out using a 4-bar model. The experiment comprised a water-cooled internal tube, and three insulated heatable outer test bars. The system was subjected to alternating axial forces, superimposed with alternating temperatures at the outer bars. The test parameters were partly selected on the basis of previous shakedown analyses. During the test, temperatures and strains were measured as a function of time. The loads and the resulting stresses were confirmed on an ongoing basis during performance of the test, and after it. Different material models were applied for this incremental elasto-plastic analysis using the ANSYS program. The results of the simulation are used to verify the FEM-based shakedown analysis. KW - Materialermüdung KW - Einspielen KW - Materialermüdung KW - shakedown analyses KW - thermal ratcheting KW - fatigue analyses Y1 - 2001 ER - TY - JOUR A1 - Staat, Manfred T1 - Direct FEM Limit and Shakedown Analysis with Uncertain Data N2 - 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. KW - Finite-Elemente-Methode KW - Einspielen KW - FEM KW - Einspielanalyse KW - shakedown KW - limit load KW - reliability analysis KW - FEM KW - direct method Y1 - 2000 ER - TY - JOUR A1 - Staat, Manfred T1 - Basis Reduction for the Shakedown Problem for Bounded Kinematic Hardening Material N2 - 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. KW - Finite-Elemente-Methode KW - Einspielen KW - Basis Reduktion KW - konvexe Optimierung KW - FEM KW - Druckgeräte KW - Basis reduction KW - Convex optimization KW - FEM KW - Shakedown analysis Y1 - 2000 ER - TY - CHAP A1 - Staat, Manfred T1 - Limit and shakedown analysis under uncertainty T2 - Proceedings International Conference on Advances in Computational Mechanics (ACOME) Y1 - 2012 N1 - International Conference on Advances in Computational Mechanics (ACOME), August 14-16, 2012, Ho Chi Minh City, Vietnam SP - 837 EP - 861 ER - TY - JOUR A1 - Staat, Manfred T1 - LISA - a European project for FEM-based limit and shakedown analysis N2 - 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. KW - Einspielen KW - Traglast KW - Finite-Elemente-Methode KW - Traglastanalyse KW - Einspielanalyse KW - FEM KW - limit analysis KW - shakedown analysis Y1 - 2001 ER - TY - JOUR A1 - Staat, Manfred T1 - Anisotrope Wellenausbreitung in isotropen hyperelastischen Scheiben JF - Zeitschrift für angewandte Mathematik und Mechanik : ZAMM. 67 (1987), H. 4 Y1 - 1987 SN - 0946-8463 SP - T241 EP - T243 ER - TY - JOUR A1 - Staat, Manfred T1 - Limit and shakedown analysis under uncertainty JF - International journal of computational methods : IJCM Y1 - 2013 SN - 0219-8762 SP - Publ. online PB - World Scientific Publishing CY - Singapore ER -