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 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 - Klassen, Jakob A1 - Nitschke-Pagel, Thomas A1 - Dilger, Klaus A1 - Launert, Benjamin T1 - Welding of thick steel plates under rough environmental conditions T2 - 7th Asia Pacific IIW International Congress N2 - Large-scale steel structures are not created on the site. Assembly groups are prefabricated under shop conditions and transported to the site, where the final assembly process takes place. Due to the advantages of manufacturing in a workshop, e.g. the defined ambient conditions, those assembly parts are as big as the transportation possibilities. The final assembling on the site is exposed to the ambient conditions there, which is why assembling on site may be conducted at temperatures below freezing point. Thus high cooling rates induce phase transformations at low temperature and therefore local hardening and are also affecting shrinkage, distortion and residual stresses. Before approving the construction designers need to estimate occurring shrinkage, distortions and residual stresses never knowing what the construction workers on the site really do. It is impossible to supervise or monitor the whole assembling process. That is why it is necessary to think about possible worst cases like clamped welding components, although a clamp was not to be set. Construction workers might apply fixations in order to adhere to specifications, thus creating residual stresses which may have a significant impact on the fatigue behaviour of a construction. In this paper large-scale specimens are investigated. These were derived from actual bridge girders and welded in a climatic chamber simulating different cooling rates on the site (up to -10°C). Welding experiments were accompanied by distortion and temperature field monitoring. Afterwards residual stresses were determined using x-ray diffraction. Finally welding distortions and residual stresses are calculated using numerical welding simulation. The simulated and experimental results are compared. KW - Assembly joints, Low ambient temperatures, Welding experiments, Numerical welding simulation Y1 - 2013 UR - http://www.iiwelding.org/Publications/TechnicalDB/Pages/Default.aspx N1 - ICRA-2013-SING.190 ER - TY - CHAP A1 - Pasternak, Hartmut A1 - Launert, Benjamin T1 - Improved design approaches for the load bearing capacity of welded I-profiles from high strength steel considering realistic residual stresses T2 - 7th European Conference on Steel and Composite Structures (Eurosteel), Napoli, 2014 Y1 - 2014 SN - 978-92-9147-121-8 SP - 159 EP - 160 PB - ECCS European Convention for Constructional Steelwork CY - Brussels 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 - Tankova, Trayana A1 - Silva, Luís Simões da A1 - Balakrishnam, Marimuthu A1 - Rodrigues, Dulce A1 - Launert, Benjamin A1 - Pasternak, Hartmut A1 - Tun, Tin Yadanar T1 - Residual stresses in welded I section steel members T2 - Engineering Structures N2 - Residual stresses have major influence on the stability of steel members. It is well-known that, due to the differences in manufacturing procedures, the residual stresses for welded and hot – rolled members are rather different. In the same way, despite several studies on residual stresses distribution and magnitude for hot-rolled members were already done, for prismatic and tapered welded I section steel members the investigation is still very scarce. In the current work, an experimental programme on the buckling resistance of tapered members, with different tapering ratios and section heights, was conducted and residual stress measurements were carried out using the sectioning method. Numerical simulations of the heat input during welding were also performed in order to predict the residual stress fields. A statistical analysis of the residual stresses distribution for welded I section members was performed, using the experimental and numerical results, as well as literature data. Systematized information on residual stresses distribution and magnitude was generated and some guidelines for the statistical characterization of residual stresses in welded members were proposed. KW - Residual stresses KW - Welded sections KW - Steel KW - Eurocode 3 KW - Stability KW - Welding simulation KW - I section KW - Experimental tests Y1 - 2019 U6 - https://doi.org/10.1016/j.engstruct.2019.109398 SN - 0141-0296 VL - 197 ER - TY - GEN A1 - Stapelfeld, Christoph A1 - Launert, Benjamin A1 - Pasternak, Hartmut A1 - Doynov, Nikolay A1 - Michailov, Vesselin T1 - Improve load capacity calculations by considering realistic imperfections induced by welding for plates and shells T2 - Stability and ductility of steel structures 2019 : proceedings of the International Colloquia on Stability and Ductility of Steel Structures (SDSS 2019), September 11-13, 2019, Prague, Czech Republic Y1 - 2019 UR - https://www.b-tu.de/fg-stahlbau/publikationen/veroeffentlichungen SN - 978-0-367-33503-8 SP - 1059 EP - 1067 PB - CRC Press CY - Boca Raton ER - TY - GEN A1 - Launert, Benjamin A1 - Li, Zheng A1 - Pasternak, Hartmut ED - Zingoni, Alphose T1 - Development of a new method for the direct numerical consideration of welding effects in the component design of welded plate girders 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 - 1143 EP - 1147 PB - Taylor & Francis Group CY - London ER -