@inproceedings{KuehhornGolze, author = {K{\"u}hhorn, Arnold and Golze, Mark}, title = {An Improved Sandwich Theory for a Better Prediction of the Wrinkling Phenomenon}, series = {Proceedings of the Fifth World Congress on Computational Mechanics, Vienna, Austria, July 7 - 12, 2002, held at Vienna University of Technology}, booktitle = {Proceedings of the Fifth World Congress on Computational Mechanics, Vienna, Austria, July 7 - 12, 2002, held at Vienna University of Technology}, address = {Vienna}, isbn = {3-9501554-0-6}, abstract = {An advanced design of sandwichstructures does not only require the knowledge of the global stress- and deformation behavior, but also the knowledge of the local effects, such as load singularities and the loss of stability caused by the short wave wrinkling of one (bending) or both (pressure) sandwich skins.Based on the nonlinear theory for sandwich shells with seven kinematic degrees of freedom, introduced from K{\"u}hhorn and Schoop an improved theory for plane sandwich shells with eight degrees of freedom will be presented, enabling a much better representation of the sandwich core behavior.Due to consideration of quadratic core thickness and linear core shear strain as well as longitudinal core deformation an improved prediction of the wrinkling behavior is succeeded even for thick cores and thin skins.The kinematic quantities as well as the nonlinear-differential equations and the simplified equations of first order theory resulting from them are given.Finally applying the well known classical problems of stability loaded by pressure and bending, the efficiency of this 8 DOF-theory ist demonstrated. A comparison with a detailed finite element (plain strain) calculation shows the high quality of these results.The presented sandwich theory characterized by eight degrees of freedom enables the calculation of nearly all essential sandwich phenomena even for thick cores.}, language = {en} } @article{KuehhornBeirow, author = {K{\"u}hhorn, Arnold and Beirow, Bernd}, title = {Schwingungsreduzierung an der Antriebseinheit eines Ultraleichtflugzeuges}, series = {Forum der Forschung}, volume = {6}, journal = {Forum der Forschung}, edition = {14}, issn = {0947-6989}, pages = {105 -- 108}, abstract = {Auf Grund der im Rahmen eines Testfluges subjektiv durch den Piloten festgestellten hohen Schwingungsamplituden wird das dynamische Verhalten eines Ultraleichtflugzeugmotors inklusive der Motoraufh{\"a}ngung untersucht. Hierin wir der numerische Teil der Untersuchun-gen durch eine finite Elemente Simulation abgedeckt, in deren Rahmen die wesentlichen Ei-genschwingformen der Antriebseinheit samt Motortr{\"a}ger identifiziert wurden. Erg{\"a}nzend mit den Ergebnissen einer experimentellen Modalanalyse und Betriebsschwingungsmessungen konnten wesentliche Informationen gewonnen werden, aus denen als Maßnahme zur Schwin-gungsreduzierung die Erh{\"o}hung der Schwungradmasse abgeleitet wurde.}, language = {de} } @inproceedings{ChmielewskiGorskiBeirowetal., author = {Chmielewski, Tadeusz and Gorski, Piotr and Beirow, Bernd and Kretzschmar, Joachim}, title = {Comparison of Theoretical and Experimental Free Vibrations of High Industrial Chimney Interacting with Soil}, series = {Teoria konstrukcji, konstrukcje metalowe, konstrukcje betonowe, XLVIII Konferencja Naukowa Komitetu Inżynierii Lądowej i Wodnej PAN i Komitetu Nauki PZITB Krynica 2002, Opole-Krynica 15-20 września 2002 r.}, booktitle = {Teoria konstrukcji, konstrukcje metalowe, konstrukcje betonowe, XLVIII Konferencja Naukowa Komitetu Inżynierii Lądowej i Wodnej PAN i Komitetu Nauki PZITB Krynica 2002, Opole-Krynica 15-20 września 2002 r.}, publisher = {Dolnośląskie Wydaw. Edukacyjne}, address = {Wrocław}, isbn = {83-7125-091-6}, pages = {27 -- 34}, abstract = {Theoretical frequencies and mode shapes of the high multi-flue industrial chimney, which is located in the power station of Opole, interacting with soil have been evaluated through the application of the finite element method. The aim of the present paper is to study the free vibrations of this chimney applying dynamic testing in full scale to confirm a calculation model and to obtain important information on the effect of soil interacting with the chimney.}, language = {en} } @inproceedings{KuehhornGolze, author = {K{\"u}hhorn, Arnold and Golze, Mark}, title = {Thickness flexible theory with generalized core warping for plane sandwich-structures}, abstract = {An advanced design of sandwichstructures does not only require the knowledge of the global stress- and deformation behavior, but also the knowledge of the local effects, such as load singularities and the loss of stability caused by the short wave wrinkling of one (bending) or both (pressure) sandwich skins.Based on the nonlinear theory for sandwich shells with seven kinematic degrees of freedom, introduced from K{\"u}hhorn and Schoop an improved theory for plane sandwich shells with eight degrees of freedom (position vector r, director d, and intensity factors az1, az2 for including core flexibility) will be presented, enabling a much better representation of the sandwich core behavior.Due to consideration of quadratic core thickness and linear core shear strain as well as longitudinal core deformation an improved prediction of the wrinkling behavior is succeeded even for thick cores and thin skins.The kinematic quantities as well as the nonlinear-differential equations achieved from the principle of virtual work and the simplified equations of first order theory resulting from them are given.Finally applying the well known classical problems of stability loaded by pressure and bending, the efficiency of this 8 DOF-theory is demonstrated. A comparison with a detailed finite element (plain strain) calculation shows the high quality of these results.The presented sandwich theory characterized by eight kinematic degrees of freedom is valid for arbitrary displacements, rotations and moderat strains enables the calculation of nearly all essential sandwich phenomena even for thick cores.}, language = {en} } @inproceedings{GolzeKuehhorn, author = {Golze, Mark and K{\"u}hhorn, Arnold}, title = {CFK-/GFK-Auslegung am Beispiel eines Modellfl{\"u}gels}, series = {Tagungsband, 14. deutschsprachiges ABAQUS Anwendertreffen, 23. - 24. September 2002 in Wiesbaden}, booktitle = {Tagungsband, 14. deutschsprachiges ABAQUS Anwendertreffen, 23. - 24. September 2002 in Wiesbaden}, publisher = {ABACOM Software GmbH}, address = {Aachen}, abstract = {{\"O}konomische und {\"o}kologische Bed{\"u}rfnisse verlangen von modernen Konstruktionen sowohl eine hochintegrative Bauweise als auch eine massive Gewichtseinsparung. Dies f{\"u}hrt zu neuen Leichtbaukonstruktionen mit einem stetig zunehmenden Anteil an Faserverbundl{\"o}sungen. Die hierbei er{\"o}ffnete M{\"o}glichkeit, kraftfluß- und beanspruchungsgerecht auszulegen, erschließt sich erst vollst{\"a}ndig durch die sichere Anwendung moderner FE-Programme wie beispielsweise ABAQUS. Nutzt man dar{\"u}ber hinaus die M{\"o}glichkeit der flexiblen Script-Programmierung, so lassen sich wirkungsvolle Effizienzsteigerungen durch die gezielte Erstellung spezifischer Eingabemen{\"u}s und Ausgaberoutinen erreichen. Dieser Beitrag veranschaulicht an Hand eines ausgef{\"u}hrten und getesteten CFK-Modellfl{\"u}gels unter Biegebeanspruchung, die Vorgehensweise bei Verwendung von ABAQUS und der Script-Sprache Python.}, language = {de} } @inproceedings{StudenerKuehhorn, author = {Studener, Johannes and K{\"u}hhorn, Arnold}, title = {FE-Untersuchungen zum dynamischen Verhalten einer integralen Verdichterschaufelscheibe neuer Generation}, series = {Tagungsband, 14. deutschsprachiges ABAQUS Anwendertreffen, 23. - 24. September 2002 in Wiesbaden}, booktitle = {Tagungsband, 14. deutschsprachiges ABAQUS Anwendertreffen, 23. - 24. September 2002 in Wiesbaden}, publisher = {Abacom Software GmbH}, address = {Aachen}, abstract = {Eigenwertanalyse eines FE-Modells unter Ber{\"u}cksichtigung des Kopplungsverhaltens zwischen Schaufel und Scheibe}, language = {de} } @inproceedings{BeirowKuehhorn, author = {Beirow, Bernd and K{\"u}hhorn, Arnold}, title = {Schwingungsreduzierung an der Antriebseinheit eines Ultraleichtflugzeuges : Beitrag Deutscher Luft- und Raumfahrtkongress Stuttgart 2002}, abstract = {Initiiert durch die im Rahmen eines Testfluges subjektiv durch den Piloten festgestellten hohen Schwingungsamplituden wird das dynamische Verhalten eines Ultraleichtflugzeugmotors inklusive der Motoraufh{\"a}ngung untersucht. Hierin wir der numerische Teil der Untersuchungen durch eine finite Elemente Simulation abgedeckt, in deren Rahmen die wesentlichen Eigenschwingformen der Antriebseinheit samt Motortr{\"a}ger identifiziert wurden. Erg{\"a}nzend mit den Ergebnissen einer experimentellen Modalanalyse und Betriebsschwingungsmessungen konnten wesentliche Informationen gewonnen werden, aus denen als Maßnahme zur Schwin-gungsreduzierung die Erh{\"o}hung der Schwungradmasse abgeleitet wurde.}, language = {de} } @inproceedings{BeirowKuehhornOsterrieder, author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Osterrieder, Peter}, title = {Windinduzierte Schwingungserregung von Fernmeldet{\"u}rmen}, series = {Fluid-Struktur-Wechselwirkung, Tagung Wiesloch, 11. und 12. Juni 2002}, booktitle = {Fluid-Struktur-Wechselwirkung, Tagung Wiesloch, 11. und 12. Juni 2002}, publisher = {VDI-Verlag}, address = {D{\"u}sseldorf}, isbn = {3-18-091682-6}, pages = {407 -- 422}, abstract = {Vorstellung eines stochastischen Verfahrens zur Berechnung windinduzierter Querschwingungen, Pr{\"a}sentation am Beispiel des Fernmeldeturmes Cottbus}, language = {de} } @article{KuehhornBeirowStudener, author = {K{\"u}hhorn, Arnold and Beirow, Bernd and Studener, Johannes}, title = {Messtechnische Beanspruchungsuntersuchungen beim Transport von Glasr{\"o}hrenkollektoren}, language = {de} } @article{KuehhornKlaukeGolze, author = {K{\"u}hhorn, Arnold and Klauke, Thomas and Golze, Mark}, title = {Simulation und Verifikation der sukzessiven Bruchabfolge eines CFK-Bauteils mittels neuartiger Bruchkriterien}, language = {de} } @article{KuehhornBeirowKlaukeetal., author = {K{\"u}hhorn, Arnold and Beirow, Bernd and Klauke, Thomas and Golze, Mark}, title = {Simulation der Mistuningeffekte von Hochdruckverdichter-Schaufelscheiben zur Bestimmung kritischer Schwingungen in Flugtriebwerken}, language = {de} } @inproceedings{BeirowOsterriederKuehhorn, author = {Beirow, Bernd and Osterrieder, Peter and K{\"u}hhorn, Arnold}, title = {Stochastisches Konzept f{\"u}r die Berechnung von Stahlschornsteinen infolge wirbelerregter Querschwingungen}, series = {Berichte der Fachtagung Baustatik - Baupraxis 8, am 21. und 22. M{\"a}rz 2002 in Braunschweig}, booktitle = {Berichte der Fachtagung Baustatik - Baupraxis 8, am 21. und 22. M{\"a}rz 2002 in Braunschweig}, editor = {Dinkler, Dieter}, publisher = {TU, Institut f{\"u}r Statik}, address = {Braunschweig}, isbn = {3-926031-95-6}, pages = {271 -- 280}, language = {de} } @book{KuehhornSilber, author = {K{\"u}hhorn, Arnold and Silber, Gerhard}, title = {Technische Mechanik f{\"u}r Ingenieure}, publisher = {H{\"u}thig-Verlag}, isbn = {3-7785-2620-0}, language = {de} } @inproceedings{KretzschmarBeirow, author = {Kretzschmar, Joachim and Beirow, Bernd}, title = {Dynamic Diagnostic of Timber Structures Supported by Neural Networks}, language = {de} } @phdthesis{Springmann, author = {Springmann, Marcel}, title = {Identifikation von Materialparametern sch{\"a}digungsmechanischer Gesetze unter Einbeziehung der Dehnungslokalisierung}, publisher = {Mensch und Buch Verl.}, address = {Berlin}, isbn = {3-89820-926-1}, pages = {XII, 169}, language = {de} } @inproceedings{MuellerWahlichKrottenthaler, author = {M{\"u}ller, T. and Wahlich, R. and Krottenthaler, P.}, title = {Modelling and experimental verification of the 300mm Ar Anneal Process}, language = {en} } @inproceedings{StudenerKuehhorn, author = {Studener, Johannes and K{\"u}hhorn, Arnold}, title = {Thermomechanische Simulation des Annealprozesses von großen Siliziumwafern}, series = {Tagungsband, 17. Deutschsprachige ABAQUS-Benutzerkonferenz 2005, 19. - 20. September 2005, N{\"u}rnberg}, booktitle = {Tagungsband, 17. Deutschsprachige ABAQUS-Benutzerkonferenz 2005, 19. - 20. September 2005, N{\"u}rnberg}, publisher = {ABAQUS Deutschland GmbH}, address = {Aachen [u.a.]}, language = {de} } @inproceedings{KlaukeBeirowKuehhorn, author = {Klauke, Thomas and Beirow, Bernd and K{\"u}hhorn, Arnold}, title = {Experimental and numerical investigations of blade mistuning and strain gauge application effects in aero engine development}, language = {en} } @misc{ChmielewskiGorskiBeirowetal., author = {Chmielewski, Tadeusz and Gorski, Piotr and Beirow, Bernd and Kretzschmar, Joachim}, title = {Theoretical and experimental free vibrations of tall industrial chimney with flexibility of soil}, series = {Engineering structures}, volume = {27}, journal = {Engineering structures}, number = {1}, issn = {0141-0296}, pages = {25 -- 34}, language = {en} } @inproceedings{BeirowKuehhornGolzeetal., author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Golze, Mark and Klauke, Thomas}, title = {Strukturdynamische Untersuchungen an Hochdruckverdichterschaufelscheiben unter Ber{\"u}cksichtigung von Mistuningeffekten}, series = {Modalanalyse und Identifikation, Verfahren und Anwendungen bei dynamischen Systemen, Tagung Wiesloch, 25. und 26. Mai 2004}, booktitle = {Modalanalyse und Identifikation, Verfahren und Anwendungen bei dynamischen Systemen, Tagung Wiesloch, 25. und 26. Mai 2004}, publisher = {VDI-Verlag}, address = {D{\"u}sseldorf}, isbn = {3-18-091825-X}, pages = {351 -- 372}, language = {de} } @inproceedings{KlaukeKuehhornBeirow, author = {Klauke, Thomas and K{\"u}hhorn, Arnold and Beirow, Bernd}, title = {Numerische Untersuchung des Schwingverhaltens von Hochdruckverdichter-Blisks mit fertigungsbedingten Anweichungen}, language = {de} } @inproceedings{KunaSpringmann, author = {Kuna, M. and Springmann, Marcel}, title = {Determination of ductile damage parameters by local deformation fields}, language = {en} } @inproceedings{KlaukeKuehhornLiangetal., author = {Klauke, Thomas and K{\"u}hhorn, Arnold and Liang, Luo and Kober, Markus}, title = {Entwicklung eines 3-Blatt-CFK-Verstellpropellers f{\"u}r Ultraleichtflugzeuge}, abstract = {Internationale AVK-Tagung, 13.-14. September 2010, Essen}, language = {de} } @inproceedings{KlaukeKuehhornLiangetal., author = {Klauke, Thomas and K{\"u}hhorn, Arnold and Liang, Luo and Kober, Markus and Sieghart, D. and F{\"u}hrer, M. and Viehweger, Bernd and Fritzsche, Christoph and Sarradj, Ennes}, title = {Entwicklung eines 3-Blatt-CFK-Verstellpropellers f{\"u}r Ultraleichtflugzeuge}, abstract = {Deutscher Luft- und Raumfahrkongress 2010, 31.08. - 02.09.2010, Hamburg}, language = {de} } @misc{SpringmannKuehhornFilipiaketal., author = {Springmann, Marcel and K{\"u}hhorn, Arnold and Filipiak, A. and Hugler, Daniel and Dufor, K.-H.}, title = {Generisches Flugtriebwerksmodell f{\"u}r die Anwendung in der Vorentwicklungsphase}, language = {de} } @inproceedings{StrehlauKuehhorn, author = {Strehlau, Ulrik and K{\"u}hhorn, Arnold}, title = {Effects of blade mistuning on frequency veering regions of real HPC blisks}, language = {en} } @misc{KoberKuehhorn, author = {Kober, Markus and K{\"u}hhorn, Arnold}, title = {Development of optimized washer-shape for damage-free load application to composites}, series = {Composite Structures}, volume = {92}, journal = {Composite Structures}, number = {9}, issn = {0263-8223}, pages = {1985 -- 1991}, language = {de} } @inproceedings{Kober, author = {Kober, Markus}, title = {HyperWorks im Einsatz in der Lehre}, language = {de} } @inproceedings{StrehlauKuehhorn, author = {Strehlau, Ulrik and K{\"u}hhorn, Arnold}, title = {Experimental and numerical investigations of a HPC-Blisk with focus on travelling waves}, language = {en} } @inproceedings{KoberKuehhorn, author = {Kober, Markus and K{\"u}hhorn, Arnold}, title = {Development of optimized washer shape for damage-free load application to composites}, language = {en} } @inproceedings{BeirowKuehhornNipkau, author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Nipkau, Jens}, title = {On the Influence of Strain Gauge Instrumentation on Blade Vibrations of Integral Blisk Compressor Rotors Applying a Discrete Model}, series = {Proceedings of the ASME Turbo Expo 2009, presented at the 2009 ASME Turbo Expo, June 8 - 12, 2009, Orlando, Florida, USA}, booktitle = {Proceedings of the ASME Turbo Expo 2009, presented at the 2009 ASME Turbo Expo, June 8 - 12, 2009, Orlando, Florida, USA}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4887-6}, pages = {245 -- 254}, language = {en} } @inproceedings{KlaukeKuehhornKober, author = {Klauke, Thomas and K{\"u}hhorn, Arnold and Kober, Markus}, title = {Application of a Newer Inter-Fiber-Failure Criteria on CFRPs in Aero Engine Development}, language = {en} } @inproceedings{BeirowOsterrieder, author = {Beirow, Bernd and Osterrieder, Peter}, title = {Dynamic Investigations of TV Towers}, series = {Structural engineering, mechanics, and computation, proceedings of the International Conference on Structural Engineering, Mechanics, and Computation, 2-4 April 2001, Cape Town, South Africa, Bd. 1}, booktitle = {Structural engineering, mechanics, and computation, proceedings of the International Conference on Structural Engineering, Mechanics, and Computation, 2-4 April 2001, Cape Town, South Africa, Bd. 1}, editor = {Zingoni, Alphose}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0-08-043948-9}, pages = {629 -- 636}, language = {en} } @misc{KuehhornBeirowSchrapeetal., author = {K{\"u}hhorn, Arnold and Beirow, Bernd and Schrape, Sven and Golze, Mark and Kn{\"o}pke, Martin}, title = {Simulation fluidged{\"a}mpfter Strukturschwingungen mittels partitionierter Fluid-Struktur-Kopplung}, series = {Forum der Forschung}, volume = {9}, journal = {Forum der Forschung}, number = {18}, issn = {0947-6989}, pages = {79 -- 86}, language = {de} } @inproceedings{BeirowKuehhornKlauke, author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Klauke, Thomas}, title = {Lokalisierungsph{\"a}nomen bei Hochdruckverdichterschaufelscheiben}, language = {de} } @inproceedings{Kuehhorn, author = {K{\"u}hhorn, Arnold}, title = {Flug-Triebwerkstechnik - innovative Studienrichtung an der BTU Cottbus unter Beteilugung von RRD, MTU und DLR}, series = {Deutscher Luft- und Raumfahrtkongress 2006, Braunschweig, 06. bis 09. November 2006, Bd. 1}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2006, Braunschweig, 06. bis 09. November 2006, Bd. 1}, publisher = {Dt. Ges. f{\"u}r Luft- und Raumfahrt}, address = {Bonn}, pages = {593 -- 596}, language = {de} } @article{KuehhornBeirowKlauke, author = {K{\"u}hhorn, Arnold and Beirow, Bernd and Klauke, Thomas}, title = {Theoretische und experimentelle Untersuchungen von Schaufelschwingungen bei Verdichterintegralr{\"a}dern}, language = {de} } @phdthesis{Lenk, author = {Lenk, Olaf}, title = {Charakterisierung und Anwendung von fl{\"a}chig periodischen Metall-Ringgeflechten}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-10148}, language = {de} } @misc{ZolochevskyGalishinKuehhornetal., author = {Zolochevsky, Alexander and Galishin, A. and K{\"u}hhorn, Arnold and Springmann, Marcel}, title = {Transversal Shear Effect in Moderately Thick Shells from Materials with Characteristics Dependent on the Kind of Stress State under Creep-Damage Conditions: Numerical Modeling}, language = {en} } @misc{ZolochevskyGalishinKuehhornetal., author = {Zolochevsky, Alexander and Galishin, A. and K{\"u}hhorn, Arnold and Springmann, Marcel}, title = {Transversal Shear Effect in Moderately Thick Shells from Materials with Characteristics Dependent on the Kind of Stress State under Creep-Damage Conditions: Theoretical Framework}, language = {en} } @inproceedings{StrehlauKuehhornBeirow, author = {Strehlau, Ulrik and K{\"u}hhorn, Arnold and Beirow, Bernd}, title = {Numerische und experimentelle Untersuchungen realer Hochdruckverdichterschaufelscheiben in Integralbauweise}, language = {de} } @inproceedings{KoberKuehhorn, author = {Kober, Markus and K{\"u}hhorn, Arnold}, title = {Auslegung und Optimierungsprozess einer Tragstruktur in Faserverbundbauweise unter Ber{\"u}cksichtigung moderner Versagenskriterien}, language = {de} } @misc{SpringmannKuehhornKunaetal., author = {Springmann, Marcel and K{\"u}hhorn, Arnold and Kuna, M. and Scherzer, M.}, title = {Influence of Strain Localization on Parameter Identification}, language = {en} } @inproceedings{SpringmannKuehhornFilipiaketal., author = {Springmann, Marcel and K{\"u}hhorn, Arnold and Filipiak, A. and Hugler, Daniel and Dufor, K.-H.}, title = {Automatic generation and optimization of a simplified aircraft engine model using a graphical user interface and full parameterization}, language = {en} } @inproceedings{StrehlauKuehhorn, author = {Strehlau, Ulrik and K{\"u}hhorn, Arnold}, title = {Schwingungsverhalten von Hochdruckverdichterschaufelscheiben in Integralbauweise (Blisk) unter Ber{\"u}cksichtigung h{\"o}herer Schwingungsmoden, Erzeugung und Messung von Umlaufwellen, 3D-Geometrievermessung}, series = {Deutscher Luft- und Raumfahrtkongress 2008, Darmstadt, 23. bis 25. September 2008, Bd. 1}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2008, Darmstadt, 23. bis 25. September 2008, Bd. 1}, publisher = {Dt. Ges. f{\"u}r Luft- und Raumfahrt}, address = {Bonn}, pages = {457 -- 467}, language = {de} } @inproceedings{SchrapeKuehhornNipkauetal., author = {Schrape, S. and K{\"u}hhorn, Arnold and Nipkau, Jens and Beirow, Bernd}, title = {Application of Aeroelastic Methods in Compressor Cascade Configurations Using Partitioned Code Coupling}, language = {en} } @inproceedings{SpringmannKuehhorn, author = {Springmann, Marcel and K{\"u}hhorn, Arnold}, title = {Coupled thermal-multiphase flow analysis in quenching processes for residual stress optimization in compressor and turbine disks}, series = {Proceedings of the ASME Pressure Vessels and Piping Conference - 2008, presented at 2008 ASME Pressure Vessels and Piping Conference, July 27 - 31, 2008, Chicago, Illinois, USA, Vol. 4}, booktitle = {Proceedings of the ASME Pressure Vessels and Piping Conference - 2008, presented at 2008 ASME Pressure Vessels and Piping Conference, July 27 - 31, 2008, Chicago, Illinois, USA, Vol. 4}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4827-2}, pages = {147 -- 156}, language = {en} } @inproceedings{SpringmannSchlumsKuehhorn, author = {Springmann, Marcel and Schlums, H. and K{\"u}hhorn, Arnold}, title = {Numerical simulation of quenching processes for residual stress optimization in compressor and turbine disks}, language = {en} } @inproceedings{BeirowKuehhornSchrape, author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Schrape, S.}, title = {Development of a new Nickel-base Alloy 718Plus for Compressor and Turbine disks}, language = {en} } @inproceedings{KoberKuehhornKlauke, author = {Kober, Markus and K{\"u}hhorn, Arnold and Klauke, Thomas}, title = {Auslegung einer Flanschverbindung aus faserverst{\"a}rktem Kunststoff durch Optimierung der Faserorientierungen und Schichtdicken mit Hilfe von Altair HyperStudy unter Verwendung eines Wirkebenenbruchkriteriums als Nebenbedingung}, language = {de} } @inproceedings{SchrapeKuehhornNipkau, author = {Schrape, S. and K{\"u}hhorn, Arnold and Nipkau, Jens}, title = {Determination of Aerodynamic Damping of Axial-Compressor-Blades Using A Bidirectional Fluid-Structure-Simulation}, series = {1st CEAS European Air and Space Conference 2007, Deutscher Luft- und Raumfahrtkongress 2007, 10 - 13 September 2007, Berlin, Germany, Bd. 1}, booktitle = {1st CEAS European Air and Space Conference 2007, Deutscher Luft- und Raumfahrtkongress 2007, 10 - 13 September 2007, Berlin, Germany, Bd. 1}, publisher = {Dt. Ges. f{\"u}r Luft- und Raumfahrt}, address = {Bonn}, pages = {309 -- 318}, language = {en} } @inproceedings{KlaukeKuehhornBeirow, author = {Klauke, Thomas and K{\"u}hhorn, Arnold and Beirow, Bernd}, title = {Blade Mistuning Induced Blisk Vibration}, series = {1st CEAS European Air and Space Conference 2007, Deutscher Luft- und Raumfahrtkongress 2007, 10 - 13 September 2007, Berlin, Germany, Bd. 1}, booktitle = {1st CEAS European Air and Space Conference 2007, Deutscher Luft- und Raumfahrtkongress 2007, 10 - 13 September 2007, Berlin, Germany, Bd. 1}, publisher = {Dt. Ges. f{\"u}r Luft- und Raumfahrt}, address = {Bonn}, pages = {335 -- 345}, language = {en} } @inproceedings{BeirowKuehhornSchrape, author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Schrape, S.}, title = {Influence of Air Flow on Blisk Vibration Behaviour}, series = {1st CEAS European Air and Space Conference 2007, Deutscher Luft- und Raumfahrtkongress 2007, 10 - 13 September 2007, Berlin, Germany, Bd. 5}, booktitle = {1st CEAS European Air and Space Conference 2007, Deutscher Luft- und Raumfahrtkongress 2007, 10 - 13 September 2007, Berlin, Germany, Bd. 5}, publisher = {Dt. Ges. f{\"u}r Luft- und Raumfahrt}, address = {Bonn}, pages = {3127 -- 3135}, language = {en} } @inproceedings{BeirowKuehhornSchrape, author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Schrape, S.}, title = {Blisk Vibration Phenomena in Consideration of Fluid Structure Interaction}, language = {en} } @inproceedings{KoberKlaukeKuehhornetal., author = {Kober, Markus and Klauke, Thomas and K{\"u}hhorn, Arnold and Lenk, Olaf}, title = {Einbindung eines modernen Wirkebenenbruchkriteriums f{\"u}r faserverst{\"a}rkte Kunststoffe in eine Parameteroptimierung mit Altair HyperStudy}, language = {de} } @inproceedings{KoberKuehhornKlaukeetal., author = {Kober, Markus and K{\"u}hhorn, Arnold and Klauke, Thomas and Lenk, Olaf}, title = {Topology-Optimized Intermediate Casing of Aero Engine and Comparative Evaluation of Titanium and Composite Architecture in Terms of Load Capacity and Weight Reduction}, series = {Proceedings of the ASME Turbo Expo 2008, presented at the 2008 ASME Turbo Expo, June 9 - 13, 2008, Berlin, Germany, Vol. 5, part A}, booktitle = {Proceedings of the ASME Turbo Expo 2008, presented at the 2008 ASME Turbo Expo, June 9 - 13, 2008, Berlin, Germany, Vol. 5, part A}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4315-4}, pages = {69 -- 79}, language = {en} } @inproceedings{BeirowKuehhornSchrape, author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Schrape, S.}, title = {A Discrete model to consider the influence of the air flow on blade vibrations of an intergral blisk compressor rotor}, series = {Proceedings of the ASME Turbo Expo 2008, presented at the 2008 ASME Turbo Expo, June 9 - 13, 2008, Berlin, Germany, Vol. 5, part A}, booktitle = {Proceedings of the ASME Turbo Expo 2008, presented at the 2008 ASME Turbo Expo, June 9 - 13, 2008, Berlin, Germany, Vol. 5, part A}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4315-4}, pages = {381 -- 392}, language = {en} } @inproceedings{KlaukeKuehhornBeirowetal., author = {Klauke, Thomas and K{\"u}hhorn, Arnold and Beirow, Bernd and Parchem, Roland}, title = {Blade Vibration Phenomena of HPC Bliscs Considering Manufacturing Effects and Strain Gauge Application}, series = {Proceedings of the ASME Turbo Expo 2008, presented at the 2008 ASME Turbo Expo, June 9 - 13, 2008, Berlin, Germany, Vol. 5, part A}, booktitle = {Proceedings of the ASME Turbo Expo 2008, presented at the 2008 ASME Turbo Expo, June 9 - 13, 2008, Berlin, Germany, Vol. 5, part A}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4315-4}, pages = {403 -- 413}, language = {en} } @article{NipkauSchrapeBeirowetal., author = {Nipkau, Jens and Schrape, S. and Beirow, Bernd and K{\"u}hhorn, Arnold}, title = {Bestimmung aeroelastischer Parameter einer Hochdruckverdichter Stufe mit Hilfe Fluid-Struktur gekoppelter Berechnungen}, language = {de} } @inproceedings{NipkauKuehhornSchrape, author = {Nipkau, Jens and K{\"u}hhorn, Arnold and Schrape, S.}, title = {Application of Fluid-Structure-Coupling for the Determination of Aeroelastic Parameters of a High-Pressure-Compressor-Blisk-Stage}, language = {en} } @inproceedings{ZuchlinskiKuehhorn, author = {Zuchlinski, Andr{\´e} and K{\"u}hhorn, Arnold}, title = {Strukturelle Optimierung der Aufh{\"a}ngung von heckinstallierten und parametrisierten Turbofantriebwerksmodellen}, language = {de} } @inproceedings{StrehlauKuehhorn, author = {Strehlau, Ulrik and K{\"u}hhorn, Arnold}, title = {Research of higher modes E3E/1 stage 1 demonstrator blisk}, language = {en} } @inproceedings{SchrapeKuehhornNipkau, author = {Schrape, S. and K{\"u}hhorn, Arnold and Nipkau, Jens}, title = {Determination of Aerodynamic Damping of Axial-Compressor-Blades using Fluid-Structure-Interaction Methods}, language = {en} } @inproceedings{HoenischKuehhorn, author = {H{\"o}nisch, Peter and K{\"u}hhorn, Arnold}, title = {Experimentelle und numerische Untersuchungen des Schwingungsverhaltensrealer Radialturbinenlaufr{\"a}der in Integralbauweise (Blisk) im Hinblick auf Verstimmung und Lokalisierung}, language = {de} } @inproceedings{KuehhornStrehlau, author = {K{\"u}hhorn, Arnold and Strehlau, Ulrik}, title = {Verstimmungsuntersuchungen am Laufrad (Blisk) eines modernenFlugtriebwerk-Hochdruckverdichters}, language = {de} } @phdthesis{Strehlau, author = {Strehlau, Ulrik}, title = {Schaufelschwingungen realer integraler Verdichterlaufr{\"a}der bei zus{\"a}tzlicher Ber{\"u}cksichtigung h{\"o}herer Moden}, publisher = {Shaker Verlag}, address = {Aachen}, isbn = {978-3-8440-0491-5}, pages = {XV, 204}, abstract = {Verbunden mit der Forderung nach immer leistungsf{\"a}higeren, umweltfreundlicheren und hinsichtlich des Treibstoffverbrauchs effizienteren Triebwerken kommen in der j{\"u}ngeren Vergangenheit mehr und mehr Verdichterlaufr{\"a}der in Integralbauweise zum Einsatz.Wesentlicher Vorteil der integralen Bauteile ist eine, im Vergleich zur herk{\"o}mmlichen Bauweise von Laufr{\"a}dern mit gesteckten Schaufeln, deutliche Gewichtsreduktion. Diese ergibt sich einerseits aus der f{\"u}r die Blisk-Bauweise nicht mehr notwendigen, aufw{\"a}ndigen und massiven Schaufel-Scheibe-Fußkonstruktion sowie andererseits aus einem g{\"u}nstigeren Kraftfluss, der die Fliehkr{\"a}fte der Schaufeln direkt in die Scheibe leitet. Da hierbei im Scheibenrandbereich Material eingespart wird, ist es m{\"o}glich die Scheibe insgesamt leichter zu gestalten. Somit sind h{\"o}here Drehzahlen der Hochdruckverdichterwelle m{\"o}glich, was zu h{\"o}heren Druckverh{\"a}ltnissen f{\"u}hrt. Unter der Maßgabe eines gleichen Druckverh{\"a}ltnisses f{\"u}r den Verdichter insgesamt, kann die Anzahl der Schaufeln der Laufr{\"a}der reduziert oder es k{\"o}nnen gar ganze Verdichterstufen eingespart werden.Demgegen{\"u}ber treten jedoch Ph{\"a}nomene, die durch ein unterschiedliches strukturdynamisches Verhalten der Schaufeln untereinander verursacht werden, bei Blisks besonders hervor. Grund daf{\"u}r ist die fehlende Reibung an den in der konventionellen Bauweise vorhandenen formschl{\"u}ssigen Kontaktstellen zwischen den Schaufeln und der Scheibe. Daher ist die mechanische D{\"a}mpfung f{\"u}r Laufr{\"a}der in Integralbauweise deutlich kleiner als f{\"u}r vergleichbare Laufr{\"a}der mit gesteckten Schaufeln.Mit zahlreichen numerischen Berechnungen und Experimenten an einer Rotorstufe aus einem im heutigen Triebwerksbau {\"u}blichen Hochdruckverdichter wird das strukturdynamische Verhalten diskutiert, wobei neben den drei Grundmodenfamilien wie erster und zweiter Biegung sowie der ersten Torsion auch h{\"o}here Modenfamilien untersucht werden. Grundlage f{\"u}r die numerischen Untersuchungen des verstimmten Rechenmodells sind schaufelindividuelle Verstimmungsmessungen, aus denen Parameter f{\"u}r den Abgleich des unverstimmten FE-Modells hin zum verstimmten FEModell extrahiert werden. Dieser Abgleich f{\"u}hrt zu einem verstimmten Rechenmodell, welches die dynamischen Eigenschaften des realen Systems widerspiegelt.Unter der Annahme, dass die Verstimmung maßgeblich von Geometrievariationen der Schaufeln untereinander gepr{\"a}gt ist, wird eine 3D-Geometrievermessung ebenfalls mit dem Ziel durchgef{\"u}hrt, ein verstimmtes Modell zu erzeugen, welches das gemessene, strukturdynamische Verhalten der realen Struktur wiedergibt. Jedoch ergeben sich bisher zwischen den Berechnungsergebnissen des geometrieangepassten Modells und Messungen an der realen Blisk deutliche Unterschiede.Mittels einer neuartigen Methodik zur Einteilung von Eigenfrequenzen in Modenfamilien werden in dieser Arbeit Gr{\"o}ßen vorgestellt, die R{\"u}ckschl{\"u}sse {\"u}ber die Sensitivit{\"a}t einer Modenfamilie gegen{\"u}ber einer m{\"o}glichen Verstimmung zulassen. Die Einteilung der Eigenfrequenzen und dazugeh{\"o}riger Eigenformen erfolgt anhand strukturdynamischer Gesichtspunkte wie z.B. der Verzerrungsenergieverteilung auf den Schaufel- und Scheibenanteil oder anhand des modalen Vergleichskriteriums (MAC).Kernpunkt dieser Arbeit bildet die experimentelle Erregung und Messung von Umlaufwellen. Hierbei werden im Frequenzbereich gesplitteter Eigenfrequenzen des verstimmten Systems stehende sowie mit der Erregung und gegen die Erregung umlaufende erzwungene Schwingformen nachgewiesen. In diesem Zusammenhang wird ein Kriterium eingef{\"u}hrt, welches stehende und drehende Schwingformen quantitativ unterscheidet. Der Vergleich experimenteller Ergebnisse mit numerischen Berechnungen zeigt eine gute {\"U}bereinstimmung f{\"u}r die analysierten erzwungenen Schwingformen.Ein in der j{\"u}ngeren Vergangenheit in Bezug auf zyklisch rotationssymmetrische Strukturen vermehrt untersuchtes Ph{\"a}nomen, das so genannte Frequency-Veering, wird in dieser Arbeit ausf{\"u}hrlich experimentell untersucht. Zwei Frequency-Veering Bereiche zeigen sich an der untersuchten Blisk im Frequenzbereich h{\"o}herer Modenfamilien. Hierbei ergibt sich keine gr{\"o}ßere Sensibilit{\"a}t der Struktur gegen{\"u}ber ihrer Verstimmung.}, language = {de} } @misc{KoberKuehhorn, author = {Kober, Markus and K{\"u}hhorn, Arnold}, title = {Comparison of different failure criteria for fiber-reinforced plastics in terms of fracture curves for arbitrary stress combinations}, series = {Composites Science and Technology}, volume = {72}, journal = {Composites Science and Technology}, number = {15}, issn = {0266-3538}, doi = {10.1016/j.compscitech.2012.08.007}, pages = {1941 -- 1951}, language = {en} } @inproceedings{GierschBeirowPopigetal., author = {Giersch, Thomas and Beirow, Bernd and Popig, Frederik and K{\"u}hhorn, Arnold}, title = {FSI-based forced response analyses of a mistuned high pressure compressor blisk}, series = {10th International Conference on Vibrations in Rotating Machinery, 11-13 September 2012, IMechE London, UK}, booktitle = {10th International Conference on Vibrations in Rotating Machinery, 11-13 September 2012, IMechE London, UK}, publisher = {Woodhead Publ.}, address = {Cambridge, UK}, isbn = {978-0-85709-452-0}, language = {en} } @inproceedings{RauerKuehhornSpringmann, author = {Rauer, Georg and K{\"u}hhorn, Arnold and Springmann, Marcel}, title = {Residual Stress Simulation of an Aero Engine Disc during Heat Treatment}, series = {Proceedings of the 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012), Vienna, Austria, September 10-14, 2012}, booktitle = {Proceedings of the 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012), Vienna, Austria, September 10-14, 2012}, publisher = {Techn. Univ.}, address = {Wien}, isbn = {978-3-9502481-9-7}, language = {en} } @inproceedings{BeirowKuehhornNipkau, author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Nipkau, Jens}, title = {Schwingungsverhalten integraler Hochdruckverdichterlaufr{\"a}der unter Ber{\"u}cksichtigung von Fluid-Struktur-Wechselwirkung und Mistuning}, series = {61. Deutscher Luft- und Raumfahrtkongress 2012, 10. - 12. September 2012, Estrel Berlin}, booktitle = {61. Deutscher Luft- und Raumfahrtkongress 2012, 10. - 12. September 2012, Estrel Berlin}, publisher = {Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V.}, address = {Bonn}, pages = {9}, language = {de} } @inproceedings{ZuchlinskiKuehhornKoberetal., author = {Zuchlinski, Andr{\´e} and K{\"u}hhorn, Arnold and Kober, Markus and Wehrenpfennig, Lutz}, title = {Kombinierte Topologie- und Parameteroptimierung des Aufh{\"a}ngungssystems von heckinstallierten Turbofantriebwerken}, series = {61. Deutscher Luft- und Raumfahrtkongress 2012, 10. - 12. September 2012, Estrel Berlin}, booktitle = {61. Deutscher Luft- und Raumfahrtkongress 2012, 10. - 12. September 2012, Estrel Berlin}, publisher = {Dt. Ges. f{\"u}r Luft- und Raumfahrt}, address = {Bonn}, pages = {10}, language = {de} } @misc{ZolochevskyParkhomenkoKuehhorn, author = {Zolochevsky, Alexander and Parkhomenko, Larisa and K{\"u}hhorn, Arnold}, title = {Analysis of oxygen exchange-limited transport and chemical stresses in perovskite-type hollow fibers}, series = {Materials Chemistry and Physics}, volume = {135}, journal = {Materials Chemistry and Physics}, number = {2-3}, issn = {0254-0584}, doi = {10.1016/j.matchemphys.2012.05.031}, pages = {594 -- 603}, language = {en} } @inproceedings{GierschHoenischBeirowetal., author = {Giersch, Thomas and H{\"o}nisch, Peter and Beirow, Bernd and K{\"u}hhorn, Arnold}, title = {Forced Response Analyses of Mistuned Radial Inflow Turbines}, series = {Proceedings of the ASME Turbo Expo 2012 : presented at the 2012 ASME Turbo Expo, June 11 - 15, 2012, Copenhagen, Denmark, Vol. 7, part B}, booktitle = {Proceedings of the ASME Turbo Expo 2012 : presented at the 2012 ASME Turbo Expo, June 11 - 15, 2012, Copenhagen, Denmark, Vol. 7, part B}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4473-1}, pages = {1559 -- 1570}, language = {en} } @inproceedings{ReyVillazonKuehhornWeiss, author = {Rey Villaz{\´o}n, Jos{\´e} Maria and K{\"u}hhorn, Arnold and Weiß, Thomas}, title = {A Parametric Impact Study of the Geometry, Air System and Thermal Boundary Conditions on the Life of a Two-Stage High Pressure Turbine}, series = {Proceedings of the ASME Turbo Expo 2012, presented at The ASME 2012 Turbo Expo, June 11-15, 2012, Copenhagen, Denmark, Vol. 7, part A}, booktitle = {Proceedings of the ASME Turbo Expo 2012, presented at The ASME 2012 Turbo Expo, June 11-15, 2012, Copenhagen, Denmark, Vol. 7, part A}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4473-1}, pages = {373 -- 382}, language = {en} } @misc{deSilvaKuehhornGolze, author = {de Silva, Tina and K{\"u}hhorn, Arnold and Golze, Mark}, title = {Homogenization of thin structured sheet metals by using FEM}, series = {Proceedings in applied mathematics and mechanics : PAMM}, volume = {12}, journal = {Proceedings in applied mathematics and mechanics : PAMM}, number = {1}, doi = {10.1002/pamm.201210104}, pages = {227 -- 228}, language = {en} } @misc{ZolochevskyMartynenkoKuehhorn, author = {Zolochevsky, Alexander and Martynenko, Alexander and K{\"u}hhorn, Arnold}, title = {Structural benchmark creep and creep damage testing for finite element analysis with material tension-compression asymmetry and symmetry}, series = {Computers and Structures}, volume = {100-101}, journal = {Computers and Structures}, issn = {0045-7949}, doi = {10.1016/j.compstruc.2012.02.021}, pages = {27 -- 38}, language = {en} } @phdthesis{Kober, author = {Kober, Markus}, title = {Ein Beitrag zur strukturmechanischen Optimierung realer Bauteile in metallischer und Faserverbundbauweise unter Verwendung von wirkebenenbasierten Bruchkriterien}, publisher = {Mensch und Buch}, address = {Berlin}, isbn = {978-3-86387-085-0}, pages = {227}, language = {de} } @misc{GierschHoenischBeirowetal., author = {Giersch, Thomas and H{\"o}nisch, Peter and Beirow, Bernd and K{\"u}hhorn, Arnold}, title = {Forced Response Analyses of Mistuned Radial Inflow Turbines}, series = {Journal of Turbomachinery}, volume = {135}, journal = {Journal of Turbomachinery}, number = {3}, issn = {1528-8900}, doi = {10.1115/1.4007512}, pages = {031034-1 -- 031034-9}, abstract = {Radial turbine wheels designed as blade integrated disks (blisk) are widely used in various industrial applications. However, related to the introduction of exhaust gas turbochargers in the field of small and medium sized engines, a sustainable demand for radial turbine wheels has come along. Despite those blisks being state of the art, a number of fundamental problems, mainly referring to fluid-structure-interaction and, therefore, to the vibration behavior, have been reported. Aiming to achieve an enhanced understanding of fluid-structure-interaction in radial turbine wheels, a numerical method, able to predict forced responses of mistuned blisks due to aerodynamic excitation, is presented. In a first step, the unsteady aerodynamic forcing is determined by modeling the spiral casing, the stator vanes, and the rotor blades of the entire turbine stage. In a second step, the aerodynamic damping induced by blade vibration is computed using a harmonic balance technique. The structure itself is represented by a reduced order model being extended by aerodynamic damping effects and aerodynamic forcings. Mistuning is introduced by adjusting the modal stiffness matrix based on results of blade by blade measurements that have been performed at rest. In order to verify the numerical method, the results are compared with strain-gauge data obtained during rig-tests. As a result, a measured low engine order excitation was found by modeling the spiral casing. Furthermore, a localization phenomenon due to frequency mistuning could be proven. The predicted amplitudes are close to the measured data.}, language = {en} } @misc{MahlerdeSilvaKuehhornKober, author = {Mahler-de Silva, Tina and K{\"u}hhorn, Arnold and Kober, Markus}, title = {Developing a Simplified Surrogate Model for Structured Sheet Metals with Numerical and Experimental Comparisons}, series = {Proceedings in applied mathematics and mechanics : PAMM}, volume = {13}, journal = {Proceedings in applied mathematics and mechanics : PAMM}, number = {1}, pages = {99 -- 100}, abstract = {It is important to steadily refine lightweight designs with regard to saving resources and energy in common with good economic efficiency. Thin structured sheet metals offer significantly improved component stiffnesses in addition to an upgraded buckling behavior compared to flat, unstructured sheet metals. By using a distortion energy based homogenization method it is possible to develop a mechanical surrogate model which describes effective mean properties. The accurate selection of symmetric and periodic boundaries enables to determine the required parameters. The conditions are contemplated on elementary cells whose structural mechanical behavior is representative for the elastic behavior of large structures. By doing this, the amount of elements can be reduced and thus the calculating time of large components can considerably be saved. For an efficient surrogate model it is required to analyze and compare numerical with experimental investigations. Some different versions of optimization will be tested to get better approximation of the data.}, language = {en} } @misc{KlaukeStrehlauKuehhorn, author = {Klauke, Thomas and Strehlau, Ulrik and K{\"u}hhorn, Arnold}, title = {Integer Frequency Veering of Mistuned Blade Integrated Disks}, series = {Journal of Turbomachinery}, volume = {135}, journal = {Journal of Turbomachinery}, number = {6}, issn = {1528-8900}, doi = {10.1115/1.4024022}, pages = {061004-1 -- 061004-7}, abstract = {As a result of more balanced blade aspect ratios of modern blade-integrated disks (blisks), interactions between disk-dominated and blade-dominated modes are becoming more and more important, especially if blade mistuning is considered. The specific vibration behavior in these transition regions is characterized by a mix of both fundamental mode types into "coupled" modes. In this paper, numerical and experimental investigations based on a front high-pressure compressor (HPC) blisk stage were carried out in order to determine the effect of blade mistuning on those regions in detail. At this, effects like mode localization and amplitude magnification are found to be weakened in an integer frequency-veering zone. Contrary to this, blisks are very sensitive to mistuning in regions of pure blade-dominated mode families with high modal density.}, language = {en} } @misc{BeirowGierschKuehhornetal., author = {Beirow, Bernd and Giersch, Thomas and K{\"u}hhorn, Arnold and Nipkau, Jens}, title = {Forced Response Analysis of a Mistuned Compressor Blisk}, series = {Journal of Engineering for Gas Turbines and Power}, volume = {136}, journal = {Journal of Engineering for Gas Turbines and Power}, number = {6}, issn = {1528-8919}, doi = {10.1115/1.4026537}, pages = {13}, abstract = {The forced response of an E3E-type high pressure compressor (HPC) blisk front rotor is analyzed with regard to varying mistuning and the consideration of the fluid-structure interaction (FSI). For that purpose, a reduced order model is used in which the disk remains unchanged and mechanical properties of the blades, namely stiffness and damping, are adjusted to measured as well as intentional blade frequency mistuning distributions. The aerodynamic influence coefficient technique is employed to model the aeroelastics. Depending on the blade mode, the exciting engine order, and aerodynamic influences, it is sought for the worst mistuning distributions with respect to the maximum blade displacement based on optimization analyses. Genetic algorithms using blade-alone frequencies as design variables are applied. The validity of the Whitehead limit is assessed in this context. In particular, the question is addressed if and how far aeroelastic effects, mainly caused by aerodynamic damping, combined with mistuning can even cause a reduction of the forced response compared to the ideally tuned blisk. It is shown that the strong dependence of the aerodynamic damping on the interblade phase angle is the main driver for a possible response attenuation considering the fundamental as well as a higher blade mode. Furthermore, the differences to the blisk vibration response without a consideration of the flow and an increase of the disk's stiffness are discussed. Closing, the influence of pure damping mistuning is analyzed again using optimization.}, language = {en} } @phdthesis{Schrape, author = {Schrape, Sven}, title = {Zur Simulation von Fluid-Struktur-Wechselwirkungen schwingender Verdichtergitter mittels kommerzieller Software}, publisher = {Shaker}, address = {Aachen}, isbn = {978-3-8440-1541-6}, pages = {X, 151}, abstract = {Die vorliegende Arbeit hat zum Ziel, dem Stand der Wissenschaft und Technik entsprechende uni- und bidirektional gekoppelte Berechnungsmethoden unter Verwendung einer partitionierten Kopplung kommerzieller FE- und CFD-Programme am Lehrstuhl Strukturmechanik und Fahrzeugschwingungen der Brandenburgischen Technischen Universit{\"a}t Cottbus zu etablieren. Dazu erfolgt bez{\"u}glich der Kopplungsverfahren eine {\"U}berpr{\"u}fung der Funktionalit{\"a}t am akademischen Beispiel einer querangestr{\"o}mten, elastischen Platte. Vor dem Hintergrund der intensiven Forschung des Lehrstuhls auf dem Gebiet der Strukturdynamik integraler Verdichterlaufr{\"a}der (Blisks) schließt sich die Validierung des eingesetzten Str{\"o}mungsl{\"o}sers hinsichtlich einer transsonischen, instation{\"a}ren Verdichterstr{\"o}mung innerhalb schwingender Schaufelgitter an. Letztlich wird das grundlegende aeroelastische Verhalten eines realen Hochdruckverdichterlaufrades anhand eines unverstimmten, zweidimensionalen Modells analysiert. Ein Vergleich der Methoden zur Berechnung aeroelastischer Parameter ist Bestandteil der Untersuchungen. Basierend auf bidirektional gekoppelten Ergebnissen wird abschließend eine Verifizierung von abgeleiteten {\"a}quivalenten aerodynamischen Elementen innerhalb eines mechanischen, unverstimmten Ersatzmodells vorgestellt.}, language = {de} } @misc{BeirowGierschKuehhornetal., author = {Beirow, Bernd and Giersch, Thomas and K{\"u}hhorn, Arnold and Nipkau, Jens}, title = {Optimization-Aided Forced Response Analysis of a Mistuned Compressor Blisk}, series = {Journal of Engineering for Gas Turbines and Power}, volume = {137}, journal = {Journal of Engineering for Gas Turbines and Power}, number = {1}, issn = {1528-8919}, doi = {10.1115/1.4028095}, pages = {012504-1 -- 012504-10}, abstract = {The forced response of the first rotor of an engine 3E (technology program) (E3E)-type high pressure compressor (HPC) blisk is analyzed with regard to varying mistuning, varying engine order (EO) excitations and the consideration of aero-elastic effects. For that purpose, subset of nominal system modes (SNM)-based reduced order models are used in which the disk remains unchanged while the Young's modulus of each blade is used to define experimentally adjusted as well as intentional mistuning patterns. The aerodynamic influence coefficient (AIC) technique is employed to model aero-elastic interactions. Furthermore, based on optimization analyses and depending on the exciting EO and aerodynamic influences it is searched for the worst as well as the best mistuning distributions with respect to the maximum blade displacement. Genetic algorithms using blade stiffness variations as vector of design variables and the maximum blade displacement as objective function are applied. An allowed limit of the blades' Young's modulus standard deviation is formulated as secondary condition. In particular, the question is addressed if and how far the aero-elastic impact, mainly causing aerodynamic damping, combined with mistuning can even yield a reduction of the forced response compared to the ideally tuned blisk. It is shown that the strong dependence of the aerodynamic damping on the interblade phase angle is the main driver for a possible response attenuation considering the fundamental blade mode. The results of the optimization analyses are compared to the forced response due to real, experimentally determined frequency mistuning as well as intentional mistuning.}, language = {en} } @misc{ZolochevskySklepusGalishinetal., author = {Zolochevsky, Alexander and Sklepus, Sergiy and Galishin, Alexander and K{\"u}hhorn, Arnold and Kober, Markus}, title = {A Comparison between the 3D and the Kirchhoff-Love Solutions for Cylinders under Creep-Damage Conditions}, series = {Technische Mechanik}, volume = {34}, journal = {Technische Mechanik}, number = {2}, pages = {104 -- 113}, language = {en} } @phdthesis{Studener, author = {Studener, Johannes}, title = {Zur thermomechanischen Modellierung von Annealprozessen f{\"u}r große Silizium-Waferscheiben}, publisher = {Der Andere Verlag}, address = {Uelvesb{\"u}ll}, isbn = {978-3-89959-502-4}, pages = {XI, 140}, abstract = {Diese Arbeit besch{\"a}ftigt sich mit einem Prozeßschritt bei der Herstellung von Siliziumwafern, welche als Ausgangsprodukt f{\"u}r Halbleiterbauelemente dienen. Die Wafer durchlaufen bei der Herstellung unterschiedliche Prozesse, unter anderem das Annealing. W{\"a}hrend des Anneals werden intrinsische Kristalldefekte, sog. Crystal originated Pits (COPs), bei {\"u}ber 1000°C thermisch aufgel{\"o}st. Der Temperaturbereich liegt dabei 200-300 °C unterhalb der Schmelztemperatur von Silizium. Demzufolge ist die Fließgrenze extrem herabgesetzt, so daß es infolge mechanischer und thermischer Belastungen zum Vergleiten (Fließen) im Kristallgitter und damit zur Qualit{\"a}tsbeeintr{\"a}chtigung kommen kann. Es wird erstmals aus mechanischer Sicht der komplexe Annealprozeß mit allen Einzelaspekten simulatorisch abgebildet und quantitativ erfaßbar gemacht. Dabei wird zum Einen das Ziel verfolgt, ein Lagerungskonzept zu entwickeln, welches den Anspr{\"u}chen an Reinheit, Temperaturbest{\"a}ndigkeit und Herstellbarkeit gerecht wird und zum Anderen den gesamten Anneal - Prozeß so zu gestalten, daß die Ausbeute von Wafern pro Zeiteinheit maximiert wird, ohne mit unerw{\"u}nschten Vergleitungen rechnen zu m{\"u}ssen. Die vorliegende Arbeit gliedert sich in einen Grundlagenteil und einen praktischen Teil. Wesentlich f{\"u}r die Erfassung des Prozesses im Simulationsmodell sind verschiedene Effekte, welche zun{\"a}chst theoretisch anhand einfacher analytischer und numerischer Beispiele, sowie versuchstechnisch aufgearbeitet werden sollen. Die in der Arbeit untersuchten Effekte beziehen sich auf: - die besonderen Materialeigenschaften des Silizium - Einkristalls, insbesondere dessen temperaturabh{\"a}ngige Fließgrenze (Upper Yield Stress) - das Lagerungskonzept, verbunden mit Kontaktproblemen zwischen Wafer und Lager (Support) - das Biegeproblem im Wafer - das Aufheizproblem bedingt durch die W{\"a}rme{\"u}bertragungsmechanismen Strahlung (zwischen Ofenwand und Wafer/Support), Leitung (innerhalb des Wafers und des Supports) und Konvektion des Gases (innerhalb des Ofens) Im praktischen Teil soll der Anneal mit Hilfe von Simulationssoftware (Finite Elemente Methode, Computational Fluid Dynamics), durch Optimierung der Lagerung und des Aufheizprozesses verbessert werden. F{\"u}r die Bearbeitung dieses Kapitels werden die Untersuchungen aus dem theoretischen Teil der Arbeit als Referenz herangezogen.}, language = {de} } @inproceedings{KoberKuehhornKaestneretal., author = {Kober, Markus and K{\"u}hhorn, Arnold and K{\"a}stner, Benjamin and Keskin, Akin}, title = {Evaluation of the Stress and Displacement Behavior of Different LS-Dyna Element Types in Combination with Different Anti-Hourglassing Formulations and Initial Element Deformations}, series = {Kurzfassungen der Vortr{\"a}ge, 13. LS-DYNA Forum 2014, 6. - 8. Oktober 2014, Bamberg}, booktitle = {Kurzfassungen der Vortr{\"a}ge, 13. LS-DYNA Forum 2014, 6. - 8. Oktober 2014, Bamberg}, publisher = {DYNAmore GmbH}, address = {Stuttgart}, isbn = {978-3-9816215-1-8}, language = {en} } @inproceedings{KoberKuehhornStelldingeretal., author = {Kober, Markus and K{\"u}hhorn, Arnold and Stelldinger, Enrico and Keskin, Akin}, title = {Identification of Stiffness Parameters of a Simplified Aero-Engine Mount System by Using a Higher Fidelity Model of the Mount System}, series = {Kurzfassungen der Vortr{\"a}ge, 13. LS-DYNA Forum 2014, 6. - 8. Oktober 2014, Bamberg}, booktitle = {Kurzfassungen der Vortr{\"a}ge, 13. LS-DYNA Forum 2014, 6. - 8. Oktober 2014, Bamberg}, publisher = {DYNAmore GmbH}, address = {Stuttgart}, isbn = {978-3-9816215-1-8}, language = {en} } @misc{KoberKuehhornRademannetal., author = {Kober, Markus and K{\"u}hhorn, Arnold and Rademann, J{\"o}rg and M{\"u}ck, Bernhard}, title = {Nonlinear topology optimization of centrifugally loaded aero-engine part with newly developed optimality-criteria based algorithm}, series = {Aerospace Science and Technology}, volume = {Vol. 39}, journal = {Aerospace Science and Technology}, doi = {10.1016/j.ast.2014.09.005}, pages = {705 -- 711}, abstract = {In this paper a successful topology optimization of a centrifugally loaded aero-engine part is presented. For the topology optimization, which is a nonlinear problem due to several contact regions, a self-developed topology optimization algorithm in combination with a commercial FE-solver is used. The goal of the optimization was the reduction of stresses in the structure. ©2014 Rolls-Royce Deutschland Ltd \& Co. KG. Published by Elsevier Masson SAS. All rights reserved.}, language = {en} } @misc{StelldingerKuehhornKober, author = {Stelldinger, Enrico and K{\"u}hhorn, Arnold and Kober, Markus}, title = {Experimental evaluation of the low-velocity impact damage resistance of CFRP tubes with integrated rubber layer}, series = {Composite Structures}, journal = {Composite Structures}, number = {139}, issn = {0263-8223}, doi = {10.1016/j.compstruct.2015.11.069}, pages = {30 -- 35}, abstract = {The impact performance of structural components made of fibre-reinforced plastic is often one of the limiting properties during the design process. To improve the damage resistance regarding transverse low-velocity impact loading, a rubber layer (KRAIBON®) is integrated into the composite laminate of tubular carbon/epoxy specimens. Numerous impact tests, using two different rubber compounds and three different layups, are carried out. The specimens are impacted using a modified Charpy pendulum. Force-time histories have been used to determine the damage threshold load. To visualise damage such as delaminations and inter-fibre failures, the impacted samples have been examined using microsectioning. It is shown that a significant improvement in impact damage resistance can be achieved by integrating a rubber layer into a carbon/epoxy laminate.}, language = {en} } @misc{KoberKuehhornMueck, author = {Kober, Markus and K{\"u}hhorn, Arnold and M{\"u}ck, Bernhard}, title = {Topologieoptimierung eines fliehkraftbelasteten Triebwerkbauteils mit einfach zu implementierendem Algorithmus unter Ber{\"u}cksichtigung mehrerer Zielfunktionen}, series = {NAFEMS-Magazin : Zeitschrift f{\"u}r numerische Simulationsmethoden und angrenzende Gebiete}, journal = {NAFEMS-Magazin : Zeitschrift f{\"u}r numerische Simulationsmethoden und angrenzende Gebiete}, number = {35}, issn = {2311-522x}, pages = {56 -- 66}, language = {de} } @inproceedings{FigaschewskyGierschKuehhorn, author = {Figaschewsky, Felix and Giersch, Thomas and K{\"u}hhorn, Arnold}, title = {Forced Response Prediction of an Axial Turbine Rotor With Regard to Aerodynamically Mistuned Excitation}, series = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25896}, booktitle = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25896}, publisher = {ASME}, isbn = {978-0-7918-4577-6}, doi = {10.1115/GT2014-25896}, pages = {13}, abstract = {The design of both efficient and reliable turbomachinery blades demands a detailed knowledge of static and dynamic forces during operation. This paper aims to contribute to the proper identification of dynamic excitation mechanisms acting on an axial turbine rotor, particularly with regard to deviations of the NGV's nominal geometry due to the use of variable vanes or tolerances in manufacturing. As variations of the NGV's geometry disturb the perfectly periodic pattern of the downstream flow features, other spectral components than those correlated with the number of stator vanes are possible to appear. These frequency components may lead to low engine order excitation of fundamental blade modes at high engine speeds. Under these operating conditions the rotor is already highly loaded with centrifugal forces and additional dynamic excitation may cause unacceptable stresses. Thus aerodynamic mistuning might be a limiting criterion for the design of a highly loaded turbine rotor. Within this paper 2 dimensional CFD-models are used to investigate both, the determination of the wake of a geometric mistuned stator guide vane and the influence of the resulting excitation on the adjacent rotor stage due to aerodynamically mistuned flow. In order to generate a mistuned NGV geometry, variations of pitch and stagger angle are taken into account and a mesh morpher is used to produce computational domains of the mistuned geometry on the basis of a nominal mesh. Additionally a simplified reconstruction process based on a set of CFD computations will be introduced, being able to reproduce the spectral components of the mistuned wake by specifying a certain geometric mistuning distribution. The prediction of the resulting modal forces is carried out in time domain and approaches with lower fidelity are investigated with respect to their capability of reproducing the key features of an aerodynamically mistuned excitation mechanism.}, language = {en} } @inproceedings{RauerKuehhornSpringmann, author = {Rauer, Georg and K{\"u}hhorn, Arnold and Springmann, Marcel}, title = {Residual Stress Modelling and Inverse Heat Transfer Coefficients Estimation of a Nickel-Based Superalloy Disc Forging}, series = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 6, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25827}, booktitle = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 6, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25827}, publisher = {ASME}, isbn = {978-0-7918-4575-2}, doi = {10.1115/GT2014-25827}, abstract = {Aero engine disc forgings are subjected to heat treatment operations, i.e., solution treatment followed by quenching and artificial aging, with the aim of achieving improved mechanical material properties. During heat treatment high inhomogeneous temperature gradients and long loading times at elevated temperatures occur and lead to the development and partial relaxation of bulk residual stresses. The intention of this paper is to describe the residual stress modelling of a nickel-based ATI 718Plus® superalloy disc forging. For this purpose, an uncoupled thermomechanical finite element problem is solved consisting of a thermal model based on transient, spatially varying heat transfer coefficients (HTCs) and a stress model incorporating the nonlinear material behaviour to account for thermal induced inelastic deformations. A graphical user interface based application has been created for the automatic estimation of the a priori unknown HTCs by using a serial solution procedure for the two dimensional inverse heat conduction problem (IHCP) based on the function specification method. The estimated temperature fields have been compared at the thermocouple positions with the corresponding measurement data and confirm the suitability of the inverse algorithm to this problem. A rate-independent elasto-plastic constitutive model is used to simulate the residual stress formation while quenching the disc forging. Two creep models have been adjusted to uniaxial tensile test data and applied to simulate the stress relaxation during aging. Finally, this paper presents the numerical results of the stress analysis. Copyright © 2014 by Rolls-Royce Deutschland Ltd \& Co KG}, language = {en} } @inproceedings{BeirowKuehhornGierschetal., author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Giersch, Thomas and Nipkau, Jens}, title = {Optimization-Aided Forced Response Analysis of a Mistuned Compressor Blisk}, series = {ASME Turbo Expo 2014, Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25915}, booktitle = {ASME Turbo Expo 2014, Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25915}, publisher = {ASME}, isbn = {978-0-7918-4577-6}, doi = {10.1115/GT2014-25915}, pages = {11}, abstract = {The forced response of the first rotor of an E3E-type high pressure compressor blisk is analyzed with regard to varying mistuning, varying engine order excitations and the consideration of aeroelastic effects. For that purpose, SNM-based reduced order models are used in which the disk remains unchanged while the Young's modulus of each blade is used to define experimentally adjusted as well as intentional mistuning patterns. The aerodynamic influence coefficient technique is employed to model aeroelastic interactions. Furthermore, based on optimization analyses and depending on the exciting EO and aerodynamic influences it is searched for the worst as well as the best mistuning distributions with respect to the maximum blade displacement. Genetic algorithms using blade stiffness variations as vector of design variables and the maximum blade displacement as objective function are applied. An allowed limit of the blades' Young's modulus standard deviation is formulated as secondary condition. In particular, the question is addressed if and how far the aeroelastic impact, mainly causing aerodynamic damping, combined with mistuning can even yield a reduction of the forced response compared to the ideally tuned blisk. It is shown that the strong dependence of the aerodynamic damping on the inter-blade phase angle is the main driver for a possible response attenuation considering the fundamental blade mode. The results of the optimization analyses are compared to the forced response due to real, experimentally determined frequency mistuning as well as intentional mistuning. Copyright © 2014 by Rolls-Royce Deutschland Ltd \& Co KG}, language = {en} } @inproceedings{GierschFigaschewskyHoenischetal., author = {Giersch, Thomas and Figaschewsky, Felix and H{\"o}nisch, Peter and K{\"u}hhorn, Arnold and Schrape, Sven}, title = {Numerical Analysis and Validation of the Rotor Blade Vibration Response Induced by High Pressure Compressor Deep Surge}, series = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-26295}, booktitle = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-26295}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4577-6}, doi = {10.1115/GT2014-26295}, pages = {12}, abstract = {The following paper presents a numerical analysis of a deep surge cycle of a 4.5 stage research compressor. The resulting unsteady loads are used to determine the response of two particular rotor blade rows that are then compared to strain gauge data from measurements. Within a deep surge cycle the compressor experiences a rapid change of the flow field from forward to reversed flow. This rapid breakdown is linked to a new mean blade load. Hence, the rapid change in blade loads are able to excite fundamental blade modes similar to an impulse load. The resulting vibration magnitudes might reach critical levels. This paper demonstrates two different approaches to evaluate the unsteady flow during a surge cycle. The first uses a three dimensional, time accurate finite volume solver for viscid compressible flows to calculate the transient surge cycle of the compressor. The compressor itself is represented by a multi-blade-row sector model. The second approach makes use of the same solver and compressor domain to determine steady state characteristics of the HPC in forward, stalled and reversed flow. Based on these characteristics an one dimensional finite volume solver for inviscid compressible flows was developed to determine the transient compressor behavior. The one dimensional solver represents the compressor by source terms that are linked to the previously determined steady state characteristics. Copyright © 2014 by Rolls-Royce Deutschland Ltd \& Co KG}, language = {en} } @inproceedings{ReyVillazonWildowKuehhornetal., author = {Rey Villaz{\´o}n, Jos{\´e} Maria and Wildow, Toni and K{\"u}hhorn, Arnold and Benton, Robert and G{\"o}hler, Moritz}, title = {Impact of the Secondary Air System Design Parameters on the Calculation of Turbine Discs Windage}, series = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 5C: Heat Transfer, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-26050}, booktitle = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 5C: Heat Transfer, D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-26050}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-4573-8}, doi = {10.1115/GT2014-26050}, pages = {9}, abstract = {The rotating components in gas turbines are very highly stressed as a result of the centrifugal and thermal loads. One of the main functions of the secondary air system (SAS) is to ensure that the rotating components are surrounded by air that optimizes disc lifing and integrity. The SAS is also responsible for the blade cooling flow supply, preventing hot gas ingestion from the main annulus into the rotor-stator cavities, and for balancing the net axial load in the thrust bearings. Thus, the SAS design requires a multidisciplinary compromise to provide the above functions, while minimizing the penalty of the secondary flows on engine performance. The phenomenon known as rotor-stator drag or windage is defined as the power of the rotor moment acting on its environment. The power loss due to windage has a direct impact on the performance of the turbine and the overall efficiency of the engine. This paper describes a novel preliminary design approach to calculate the windage of the rotor-stator cavities in the front of a typical aero engine HP turbine. The new method is applied to investigate the impact of the SAS design parameters on the windage losses and on the properties of the cooling flows leading to the main annulus. Initially, a theoretical approach is followed to calculate the power losses of each part of the HPT front air feed system. Then, a 1D-network integral model of the cavities and flow passages of the HPT front is built and enhanced with detailed flow field correlations. The new 1D-flow network model offers higher fidelity regarding local effects. A result comparison between the theoretical calculation and the prediction of the enhanced flow network model puts forward the relevance of the local flow field effects in the design concept of the SAS. Using the enhanced 1D-flow network models, the SAS design parameters are varied to assess their influence on the windage and pumping power calculation. As a conclusion, the paper shows how the SAS design can have a significant influence on the HPT overall power and the air that is fed back into the turbine blade rows. Controlling these features is essential to bid a competitive technology in the aero engine industry. Copyright © 2014 by Rolls-Royce Deutschland Ltd \& Co KG}, language = {en} } @inproceedings{BeirowMaywaldKuehhorn, author = {Beirow, Bernd and Maywald, Thomas and K{\"u}hhorn, Arnold}, title = {Mistuning and Damping Analysis of a Radial Turbine Blisk in Varying Ambient Conditions}, series = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25521}, booktitle = {ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, Volume 7B: Structures and Dynamics D{\"u}sseldorf, Germany, June 16-20, 2014, Paper GT2014-25521}, publisher = {ASME}, isbn = {978-0-7918-4577-6}, doi = {10.1115/GT2014-25521}, abstract = {A mistuned radial turbine impeller is analyzed with respect to the impact of varying ambient pressures and temperatures as well on frequency response functions and modal damping ratios. Beginning at room conditions, a finite element model of an impeller wheel at rest is updated based on experimentally determined mistuning in terms of blade dominated frequencies. The following numerical forced response analyses yield a maximum blade displacement amplification of 67\% compared to the tuned reference. In addition, modal damping ratios are determined in dependence on the ambient pressure ranging from technical vacuum at 1 mbar up to 6000 mbar in a pressure chamber. Shaker excitation and laser Doppler vibrometry response measurement is employed in this context. A linear dependence of modal damping ratios on ambient pressure and a dominating damping contribution of the surrounding air even for higher modes could be proved. Moreover, the experimental determination of frequency response functions (FRF) at technical vacuum yields a better separation of resonance peaks compared to room conditions at 1013 mbar and hence, this data allows for more accurate model-updates in principle. It is proved that numerical models updated regarding mistuning at room conditions are well suited to predict the forced response at arbitrary pressures if measured modal damping ratios at these pressures are considered. Finally, within analyzing the effect of increasing structural temperatures with the surrounding air at 1013 mbar included slightly decreasing resonance frequencies but strongly increasing FRF-amplitudes are determined. Copyright © 2014 by ASME}, language = {en} } @inproceedings{BehnamKuehhorn, author = {Behnam, Nouri and K{\"u}hhorn, Arnold}, title = {Automated CAE process for thermo-mechanical lifing prediction of a parameterized turbine blade with internal cooling}, series = {Joined 11th World Congress on Computational Mechanics (WCCM XI), 5th European Conference on Computational Mechanics (ECCM V), 6th European Conference on Computational Fluid Dynamics (ECFD VI) conference}, booktitle = {Joined 11th World Congress on Computational Mechanics (WCCM XI), 5th European Conference on Computational Mechanics (ECCM V), 6th European Conference on Computational Fluid Dynamics (ECFD VI) conference}, language = {en} } @inproceedings{ReyVillazonKuehhorn, author = {Rey Villaz{\´o}n, Jos{\´e} Maria and K{\"u}hhorn, Arnold}, title = {Adaptive CFD-Enhanced Windage Modelling for Aero Engine Turbine Rotor-Stator Cavities}, series = {Joined 11th World Congress on Computational Mechanics (WCCM XI), 5th European Conference on Computational Mechanics (ECCM V), 6th European Conference on Computational Fluid Dynamics (ECFD VI) conference}, booktitle = {Joined 11th World Congress on Computational Mechanics (WCCM XI), 5th European Conference on Computational Mechanics (ECCM V), 6th European Conference on Computational Fluid Dynamics (ECFD VI) conference}, language = {en} } @inproceedings{BehnamKuehhorn, author = {Behnam, Nouri and K{\"u}hhorn, Arnold}, title = {Interdisciplinary Analysis of a Turbine Blade With Internal Cooling Including Local Distribution and Rotation Effects}, series = {11th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, Atlanta, GA}, booktitle = {11th AIAA/ASME Joint Thermophysics and Heat Transfer Conference, Atlanta, GA}, publisher = {AIAA}, address = {Reston, VA}, isbn = {978-1-62410-281-3}, pages = {16}, language = {en} } @inproceedings{BeirowKuehhornGolzeetal., author = {Beirow, Bernd and K{\"u}hhorn, Arnold and Golze, Mark and Klauke, Thomas}, title = {Experimentelle Untersuchungen des strukturdynamischen Verhaltens von Hochdruckverdichterschaufeln in Integralbauweise (Blisks) mittels Laser-Doppler-Vibrometrie}, language = {de} }