TY - BOOK A1 - Nitschke-Pagel, Thomas A1 - Klassen, Jakob A1 - Pasternak, Hartmut A1 - Launert, Benjamin A1 - Krausche, Thomas T1 - P 858 - Schweißen dicker Bleche unter Baustellenbedingungen – Beurteilung des Einflusses auf das Tragverhalten von Montagestößen N2 - Beim Aufbau großer Stahlstrukturen im Brücken- oder Stahlhochbau wird heute vermehrt auf modulare Fabrikfertigung gesetzt. Ein Fügen dieser Module auf der Baustelle zu einer Gesamtstruktur ist aber weiterhin notwendig. Als Fügeverfahren wird hier häufig das MAG-Mehrlagenschweißen eingesetzt. Gerade an dicken Blechen stellen Baustellenschweißungen nicht nur besondere Anforderungen an den ausführenden Betrieb, die Bauleitung und Bauüberwachung, sondern auch an den Konstrukteur. Wichtig für den Konstrukteur ist die Kenntnis der sich durch Schweißungen einstellenden Schrumpfung der Bauteile, der auftretenden Verzüge und Eigenspannungen. Gerade bei Baustellenschweißungen müssen diese Aspekte in der Konstruktionsphase der Einzelkomponenten mit berücksichtigt werden, um die erforderlichen Toleranzen bei der Montage einzuhalten. Eine genaue Kenntnis der durch Schweißungen verursachten Phänomene ist in den Konstruktions- und Montagebetrieben oft nur aus mehrjährigen Erfahrungen vorhanden. Ein grundlegendes, vollständiges Bild der Abläufe beim Schweißen auf der Baustelle, das es ermöglicht, dieses Wissen auf neue Konstruktionen zu übertragen, fehlt bisher. Insbesondere für die immer öfter im Brücken- und Stahlhochbau eingesetzten höherfesten Feinkornbaustähle (z.B. S460) ist die Kenntnis des Verhaltens bei Baustellenschweißungen notwendig. Hier setzt der Forschungsantrag an. Mit Hilfe der Schweißsimulation können die Auswirkungen von Schweißnähten, wie die Entstehung von Verzügen und Eigenspannungen am Bauteil, global dargestellt werden. Eine anschließende Struktursimulationen (Festigkeits- und Steifigkeitsberechnungen) mit aus der Schweißsimulation integrierten Ergebnissen bildet die Basis für ergänzende Untersuchungen. Montagestöße sind außerdem durch Verschmutzung und Witterung negativ beeinflusst. Die Montage kann beispielsweise bei niedrigen Temperaturen unterhalb des Gefrierpunkts durchgeführt werden müssen. Diese Situation wurde in einer Klimakammer simuliert und die Auswirkungen der Umgebungstemperatur bei der Montage auf das Tragverhalten der Verbindung untersucht. Für die im Rahmen des Vorhabens untersuchten Fälle ist kein Einfluss variierender Umgebungstemperaturen bis -10 °C auf die resultierenden Schweißeigenspannungen festzustellen. Der Vergleich von Verzug und Eigenspannung gegenüber normativ vorgegeben Toleranzwerten sowie vereinfachten Ingenieurmodellen für die Approximation des Eigenspannungsverlaufs zeigt große Defizite. Bei realitätsnaher Implementierung der Eigenspannungen in die Traglastberechnung können z.T. große Reserven im Rahmen der nichtlinearen Traglastberechnung ausgenutzt werden. KW - Bauteilversuche, Stahlbau, Stabilität, Normen Y1 - 2015 UR - https://www.stahldaten.de/de/shop/fosta-berichte/werkstoffverhalten/p-858/ SN - 978-3-942541-69-5 PB - Verlag und Vertriebsgesellschaft mbH CY - Düsseldorf ER - TY - GEN A1 - Pasternak, Hartmut A1 - Krausche, Thomas A1 - Launert, Benjamin T1 - Schweißen von Trägern mit dicken Blechen, Teil 2: Schweißen unter Baustellenbedingungen – Montagestoß und Variation der Umgebungstemperatur T2 - Bauingenieur KW - Stahlbau, Stabilität, Normen Y1 - 2014 UR - www.bauingenieur.de SN - 0005-6650 VL - 89 IS - 12 SP - 537 EP - 547 ER - TY - GEN A1 - Pasternak, Hartmut A1 - Krausche, Thomas A1 - Launert, Benjamin T1 - Schweißen von Trägern mit dicken Blechen, Teil 1: Trägerfertigung unter Werksbedingungen – Planung, Herstellung und Simulation T2 - Bauingenieur KW - Stahlbau, Stabilität, Normen Y1 - 2014 UR - www.bauingenieur.de SN - 1436-4867 VL - 89 IS - 10 SP - 395 EP - 404 ER - TY - GEN A1 - Pasternak, Hartmut A1 - Krausche, Thomas A1 - Niemann, M. T1 - Umbau eines Schulgebäudes der Heinrich-Nordhoff-Gesamtschule in Wolfsburg T2 - Bauingenieur Y1 - 2014 SN - 1436-4867 SN - 0005-6650 VL - 89 IS - 4 SP - 182 EP - 185 ER - TY - CHAP A1 - Krausche, Thomas A1 - Launert, Benjamin T1 - Schweißen dicker Bleche unter Baustellenbedingungen T2 - BTU Stahlbau-Symposium 2014, Cottbus, 2014 Y1 - 2014 SP - 17 EP - 24 PB - BTU CY - Cottbus [u.a.] ER - TY - GEN A1 - Pasternak, Hartmut A1 - Launert, Benjamin A1 - Krausche, Thomas T1 - Welding of girders with thick plates — Fabrication, measurement and simulation T2 - Journal of Constructional Steel Research N2 - This article presents experimental and numerical results of the fabrication of welded plate girders under workshop conditions. Main concerns are the prediction of imperfections with the aid of simulation tools and/or simplified engineering models. Their impact on the component design is evaluated in a case study. Special focus is put on the effect of residual welding stress. For this, different simplified distributions are compared with results from welding simulation. The findings confirm the thesis that present recommendations on the implementation of weld-induced imperfections must be rated conservative. This suggests that it is necessary to establish new models. Guidance on future problems in this context will be given. KW - Welded plate girders; Welding simulation; Residual welding stress; Load capacity Y1 - 2015 UR - http://www.sciencedirect.com/science/article/pii/S0143974X15300833 U6 - https://doi.org/10.1016/j.jcsr.2015.08.037 SN - 0143-974X VL - Vol. 115 SP - 407 EP - 416 ER - TY - GEN A1 - Füg, Dieter A1 - Krausche, Thomas A1 - Webner, Michael A1 - Klenner, Frank T1 - Besonderheiten der Berechnung und konstruktiven Gestaltung von Kleinwindenergieanlagen nach DIN EN 61400–2:2006 T2 - Bauingenieur N2 - Der steigende Energiebedarf erfordert unter Beachtung des Vorrangs erneuerbarer Energiequellen wie Wind, Wasser und Sonne die Nutzung von Konstruktionslösungen, die die daraus resultierende Aufgabe der Energiegewinnung wirtschaftlich umzusetzen. Im vorliegenden Beitrag wird eine Lösung beschrieben, die helfen soll, die Windenergie zur Stromerzeugung in schlecht zugänglichen Gebieten, an Standorten mit großer Entfernung zu anderen Anlagen der Stromgewinnung oder in Gegenden für kleine Wohn- oder Industriebauten, wo die Wirtschaftlichkeit nachgewiesen werden kann, zu nutzen. Auch die Stromerzeugung für Baustellenbetrieb ist denkbar. Hierfür können Kleinwindenergieanlagen (KWEA) eine Alternative zur Stromerzeugung sein. Der vorliegende Beitrag beinhaltet Vorschläge zur konstruktiven Gestaltung, Besonderheiten der Berechnung und ein Beispiel für die Ausführung der Tragstruktur von KWEA. Grundlage für die Berechnung und Ausführung ist die DIN EN 61400–2:2006, deren Besonderheiten mit diesem Beitrag demonstriert werden. KW - Stahlbau KW - Windenergieanlagen Y1 - 2012 UR - http://www.bauingenieur.de/bauing/article.php?data[article_id]=68732 SN - 1436-4867 IS - 8 SP - 342 EP - 353 ER - TY - GEN A1 - Pasternak, Hartmut A1 - Krausche, Thomas T1 - The Porsche Pavilion in the Autostadt Wolfsburg, Germany T2 - Procedia Engineering KW - monocoque KW - stainless steel KW - innovative building design KW - construction welding KW - light steel construction Y1 - 2013 U6 - https://doi.org/10.1016/j.proeng.2013.04.010 SN - 1877-7058 IS - 57 SP - 63 EP - 69 ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Krausche, Thomas T1 - Design, constructions and assembly of two membrane-cladded double-curved cable net roofs T2 - 6th Structural Engineers World Congress (SEWC 2017), Cancun/Mexico N2 - For stadium roofs light weight constructions, that are tensioned between a cantilevering steel compression ring, are commonly build around the globe, mostly for social events like sport games and concerts. They allow having no columns in the viewing area and also spanning the whole arena. With the additional use of membranes as the roof shell, the inside of the building will get naturally lighted. With the knowledge of the occurring loads, an economic structure can be found to optimize the edge structure. Frequently the form finding process will use the death loads as decisive action because for only one load case a moment free form can be determined. Other load cases will cause bending in the girder. The process also allows having only supports at the low points and a cantilever arises. These types of roofs will be compared with two exemplary canopies in Germany. The main focus will be on the assembly of the edge girder, which will evoke challenges for planning as well as the actual manufacturing process. The steel edge girder is double curved and has a spatially shape. The welded box exists of 4 to 5 curving plates that have thicknesses from 15mm to 55mm and will vary in their height. Due to welding residual stresses occur during the assembly in the factory as well as on the construction side. For the design of the girders, the residual stresses need to be determined. The identified results of the residual stresses will vary through the plate thickness and will differ for residual longitudinal and residual transverse stresses. The longitudinal residual stresses, as the relevant residual stresses for axial forces, will be farther scrutinized. Due to its complex geometry the challenges of the simulation will be presented for the manufacturing process and the construction site assembly. For the farther investigation the calculated stresses will be taken for a load capacity calculation of a section of the edge girder. Due to the forming geometry and the welding process, both effects need to be considered. This calculation will also show that the edge girder needs to be stiffened in the inside with bulkhead plate’s und longitudinal stiffeners. Both authors are involved in the verification of the objects (Customer Centre in the Autostadt Wolfsburg-CC, Schierke-Arena ‐FA in the Harz Mountains) mentioned below. Y1 - 2017 UR - http://sewc2017.org/ PB - Universidad Nacional Autónoma de México - UNAM ER - TY - CHAP A1 - Krausche, Thomas A1 - Launert, Benjamin A1 - Pasternak, Hartmut T1 - Welding effects in unregularly steel box girders T2 - 6th Structural Engineers World Congress (SEWC 2017), Cancun/Mexico N2 - Several approaches on geometrical and structural imperfections are given in the literature for I sections and rectangular box girders. Those approximations of the residuals stress state can be implemented into the structural analysis using multi-purpose FEM program packages. The knowledge of the stress state of free forming cross sections has still to be determined. To fulfil a safe design, the assumptions mostly will be very conservative due to the lack of the assumed stress state. This will result directly to increased thicknesses or additional stiffening of the plates. Not only the material cost will rise, but also the fabrication costs like welding will be affected. This paper aims to provide an overview on the possibilities in the numerical prediction of weld residual stresses and weld induced deformations for cross sections with unique shapes. With the obtained values the tendencies of the residual stress state and deformations will be used to optimize the design. A representative example on a section used in a steel compression ring of a realized roof is described and analyzed using a simplification of a numerical welding simulation. The reduced simulation of the originally transient weld procedure was held to a practically reasonable level and can be reproduced for similar problems. The calculations used the Abaqus Welding Interface (AWI) to automate working steps in conjunction with the definition of weld passes and their sequencing. The field of the method that is discussed also a need of further investigations to prove its applicability. Some experimental back up is requires to verify the result quality. Nonetheless, this method could already help to show up tendencies or to identify potential critical spots in the design. Y1 - 2017 UR - http://sewc2017.org/ PB - Universidad Nacional Autónoma de México - UNAM ER - TY - GEN A1 - Krausche, Thomas A1 - Launert, Benjamin A1 - Pasternak, Hartmut T1 - A study on the prediction of welding effects in steel box girders T2 - Ce/papers N2 - For standard sections including I-girders and rectangular box girders, several approaches on geometrical and structural imperfections are given in the literature, which can be implemented in a numerical analysis. For complex sections, as found in many of today's lightweight roof structures, these assumptions are conservative due to the sections typically unique shape, which leads to increased thicknesses or additional stiffening of the plates. This, on the other hand, can significantly affect fabrication costs. This paper aims to provide an overview on the possibilities in the numerical prediction of weld residual stresses and weld-induced deformations for these sections. The obtained values can be used in a subsequent numerical analysis to understand the structural behavior and optimize the design. A representative example on a section used in a steel compression ring is described and analyzed using the numerical welding simulation. A simplification of the originally transient weld procedure is used in order to reduce computation times to a practically reasonable level. In this context, the Abaqus Welding Interface (AWI) helps to automate working steps in conjunction with the definition of weld passes and their sequencing, which shall be shown in here. The applicability of this method is discussed showing also a need of further investigations in this field. This is especially with regard to result quality, which requires some experimental back-up. Nonetheless, this method could already help to show up tendencies or to identify potential critical spots in the design. KW - Innovative structures KW - Welding simulation KW - Abaqus Welding Interface Y1 - 2017 UR - http://onlinelibrary.wiley.com/doi/10.1002/cepa.500/abstract U6 - https://doi.org/10.1002/cepa.500 SN - 2509-7075 VL - 1 IS - 2-3 SP - 4410 EP - 4416 ER - TY - CHAP A1 - Ragotzky, Birgit A1 - Launert, Benjamin A1 - Krausche, Thomas ED - Virdi, Kuldeep ED - Tenhunen, Lauri T1 - Welding simulation for the calculation of the welding residual stresses in welded I-girders T2 - Proceedings of the METNET Seminar 2017 in Cottbus Y1 - 2018 UR - https://issuu.com/hamkuas/docs/hamk_metnet_cottbus_2017 SN - 978-951-784-794-0 SP - 56 EP - 68 PB - Häme University of Applied Sciences (HAMK) CY - Hämeenlinna, Finland ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Krausche, Thomas T1 - A special Construction Site: the Guyed Mast at Torfhaus in the Harz Mountains, Germany T2 - Risk and Safety Engineering, 12th International Conference, Kopaonik, 2017 Y1 - 2017 UR - http://www.rizik.vtsns.edu.rs/en/zbornici-radova/ SN - 978-86-6211-107-4 SP - 540 EP - 545 PB - The Higher Education Technical School of Professional Studies CY - Novi Sad ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Krausche, Thomas T1 - Details of the steel assembly of a membrane-cladded double ­ curved cable net roof T2 - ICCAEE 2016 Kuala Lumpur/Malaysia, 2nd International Congress on Technology - Engineering & Science Y1 - 2016 PB - University of Malaysia CY - Pahang ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Krausche, Thomas A1 - Launert, Benjamin T1 - Welded construction site joints in bridges T2 - Steel Bridges: Innovation & New Challenges, 8th International Symposium on Steel Bridges, Istanbul, 2015 N2 - In large steel construction, as in steel bridges, construction site welds are made under difficult conditions such as low temperatures and wind. The comprehensive study will show not only test results from the analysis in the climate chamber (large scale test) with low temperatures (-20°C, -10°C) as well as numerical calculations with the help of welding simulation and non-linear structural analysis. Deflections and temperature are given and compared with traditional engineering models and advises for future problems are presented. For bridge girders with I cross sections, welded thick plates are used and there joining need to be considered precisely. Effect from welding, such as deflections and residual stresses, will have an outcome on the performed component. For welding of thick plates multi-layer welding is used. The edges need to be cut before welding. The preparation process needs to be considered as well as actual joining to have an economic performance. As joint geometry the Z-joint was chosen and investigated. Results from testing as well as from the welding simulation will be shown and compared. Thereby an engineering model will be consulted to evaluate the results. To evaluate the impact of the welding process a FEM load capacity calculation was performed and will be compared with test without imperfections from the joining process. KW - Welded Joints, Welding Simulation, Engineering Models, Load Capacity Calculation Y1 - 2015 SN - 978-605-65900-2-3 SP - 315 EP - 320 PB - Turkish Constructional Steelwork Association (TUCSA) CY - Istanbul, Turkey ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Krausche, Thomas T1 - The Porsche Pavilion in the Autostadt Wolfsburg, Germany T2 - 13th International Scientific Conference VSU 2013, Sofia, vol. 2 Y1 - 2013 SP - 1 EP - 6 ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Krausche, Thomas A1 - Launert, Benjamin T1 - Welding of thick steel plates under site conditions T2 - 7th European Conference on Steel and Composite Structures, Eurosteel, Neapel, 2014 Y1 - 2014 SN - 978-92-9147-121-8 SP - 109 EP - 110 PB - ECCS European Convention for Constructional Steelwork CY - Brussels ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Moradi, Milad A1 - Krausche, Thomas T1 - Reconstruction of a school building in Wolfsburg, Germany T2 - Tubular Structures XV, Proceedings of the 15th International Symposium on Tubular Structures, Rio de Janeiro, Brazil, 27-29 May 2015 Y1 - 2015 SN - 978-1-138-02837-1 SP - 31 EP - 35 PB - CRC Press CY - Hoboken ER - TY - GEN A1 - Zebinger, Markus A1 - Gierat, Marek A1 - Pasternak, Hartmut A1 - Krausche, Thomas T1 - Das Seilnetzdach der Schierker Feuerstein Arena im Harz Teil 2: Herstellung, Montage und Schweißsimulation T2 - Bauingenieur N2 - Die Stadt Wernigerode in Sachsen-Anhalt errichtete im Ortsteil Schierke eine Multifunktionsarena. Am Fuße des Brockens, dem höchsten Berg des Harzes und ganz Norddeutschlands gelegen, fügt sich die offene Überdachung in die vorhandene Topologie nahtlos ein. Das unter Denkmalschutz stehende Natureisstadion, mit seinen bestehenden Natursteinterrassen und einem Schiedsrichterturm aus Holz, wurde baulich so konzipiert, dass die Arena in den Wintermonaten als überdachte Kunsteisbahn und im Sommer als Fläche für Konzerte, Aufführungen und Sportveranstaltungen genutzt werden kann. Eine ganz besondere Herausforderung war die Herstellung und Montage des circa 190m langen geschweißten Stahlrandträgers. Der Hohlkasten besteht aus vier doppelt gekrümmten Blechen und lagert an lediglich zwei Fußpunkten auf. Der zweite Teil des Beitrags befasst sich mit Schweißeigenspannungen an einem ausgewählten Querschnitt der Überdachung. Y1 - 2018 SN - 0005-6650 VL - 93 IS - 10 SP - 383 EP - 391 ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Krausche, Thomas A1 - Launert, Benjamin T1 - Welding of Thick Plates under Site Conditions - Evaluation of the Influence on the Structure Behaviour of Welded Assembly Joints T2 - Design, fabrication and economy of metal structures, international conference proceedings 2013, Miskolc, Hungary, April 24 - 26, 2013 Y1 - 2013 SN - 978-3-642-36690-1 SP - 455 EP - 460 PB - Springer CY - Heidelberg ER - TY - CHAP A1 - Bachmann, Volkmar A1 - Krausche, Thomas A1 - Launert, Benjamin A1 - Klassen, Jakob T1 - Schweißen dicker Bleche unter Baustellenbedingungen T2 - 18. DASt-Kolloquium, Aachen, 2012 Y1 - 2012 SN - 978-3-929371-26-0 SP - 113 EP - 118 PB - Frehner Consulting CY - Füssen ER - TY - GEN A1 - Wang, Jian A1 - Euler, Mathias A1 - Pasternak, Hartmut A1 - Li, Zheng A1 - Krausche, Thomas A1 - Launert, Benjamin T1 - Bending capacity of single and double-sided welded I-section girders: Part 1: Experimental investigations T2 - Current Perspectives and New Directions in Mechanics, Modelling and Design of Structural Systems : Proceedings of The Eighth International Conference on Structural Engineering, Mechanics and Computation, 5-7 September 2022, Cape Town, South Africa N2 - The lateral-torsional buckling resistance of welded steel girders is affected by their residual stresses and geo-metric imperfections. Generally, both influences are mainly controlled by the manufacturing process, in partic-ular the welding of the girder. This paper presents experimental investigations on four laterally unbraced welded steel girders with thin-walled I-sections, whose flange-to-web junctions are welded from one or two sides to evaluate the fabrication influence. The investigations include lateral-torsional buckling tests under combined bending and torsion loading caused by three-point bending due to an eccentric vertical single force. The geometric imperfections of the welded test girders are determined by 3D laser scanning. The test results show that the influence of the geometric imperfections and the residual stresses on the lateral-torsional buck-ling resistance is limited for the tested girders. KW - Experimental investigations KW - single and double-sided welds KW - imperfections KW - lateral-torsional buckling KW - 3D laser scanning Y1 - 2022 SN - 978-1-00-334845-0 U6 - https://doi.org/10.1201/9781003348443-159 SP - 975 EP - 980 PB - CRC Press CY - Boca Raton ER - TY - GEN A1 - Pasternak, Hartmut A1 - Krausche, Thomas T1 - Design, Construction and Assembly of two Membrane-Cladded Double-Curved Net Roofs T2 - 7th International Conference Civil Engineering – Science and Practice (GNP), Kolašin, 10-14 March 2020, Book of abstracts Y1 - 2020 UR - https://de.scribd.com/document/463209242/Pasternak-Krausche-GNP2020-pdf ER - TY - GEN A1 - Pasternak, Hartmut A1 - Krausche, Thomas ED - Zingoni, Alphose T1 - Details and assembly of two cladded double curved cable net roofs T2 - Advances in engineering materials, structures and systems : innovations, mechanics and applications : proceedings of the 7th International Conference on Structural Engineering, Mechanics, and Computation (SEMC 2019), September 2-4, 2019, Cape Town, South Africa Y1 - 2019 SN - 978-1-138-38696-9 SP - 896 EP - 901 PB - Taylor & Francis Group CY - London ER -