@misc{CiupackPasternakGessleretal., author = {Ciupack, Yvonne and Pasternak, Hartmut and Geßler, Achim and Feldmann, Markus and Kasper, Yann and Albiez, Matthias and Ummenhofer, Thomas}, title = {Repair of Fatigue Cracked CT-specimens Using Adhesively Bonded CFRP Lamellas}, series = {27th Annual International Conference on Composites / Nano Engineering ICCE-27}, journal = {27th Annual International Conference on Composites / Nano Engineering ICCE-27}, pages = {2}, language = {en} } @misc{CiupackPasternak, author = {Ciupack, Yvonne and Pasternak, Hartmut}, title = {Some Remarks about the New Generation of prEN 1993-1-1}, series = {27th Annual International Conference on Composites / Nano Engineering ICCE-27}, journal = {27th Annual International Conference on Composites / Nano Engineering ICCE-27}, pages = {3}, language = {en} } @misc{TankovaSilvaBalakrishnametal., author = {Tankova, Trayana and Silva, Lu{\´i}s Sim{\~o}es da and Balakrishnam, Marimuthu and Rodrigues, Dulce and Launert, Benjamin and Pasternak, Hartmut and Tun, Tin Yadanar}, title = {Residual stresses in welded I section steel members}, series = {Engineering Structures}, volume = {197}, journal = {Engineering Structures}, issn = {0141-0296}, doi = {10.1016/j.engstruct.2019.109398}, pages = {24}, abstract = {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.}, language = {en} } @misc{DoynovStapelfeldMichailovetal., author = {Doynov, Nikolay and Stapelfeld, Christoph and Michailov, Vesselin and Pasternak, Hartmut and Launert, Benjamin}, title = {Distortion analysis of large scaled welded structures}, series = {Mathematical Modelling of Weld Phenomena 12 : selected peer reviewed papers from the 12th International Seminar Numerical Analysis of Weldability : September 23-26, 2018, Graz, Schloss Seggau - Austria}, journal = {Mathematical Modelling of Weld Phenomena 12 : selected peer reviewed papers from the 12th International Seminar Numerical Analysis of Weldability : September 23-26, 2018, Graz, Schloss Seggau - Austria}, editor = {Sommitsch, Christof and Enzinger, Norbert and Mayr, Peter}, publisher = {Verlag der Technischen Universit{\"a}t Graz}, address = {Graz}, isbn = {978-3-85125-615-4}, doi = {10.3217/978-3-85125-615-4}, pages = {254 -- 280}, abstract = {The work presents an innovative approach for simulation of welding induced distortions, which allows taking into consideration the local effects of the welding process as well as the global interactions in the structure. The approach bases on an integration of analytical and numerical calculation's procedures in a hybrid model, realized with the aid of the inherent strain concept. The analytical procedure calculates the shrinkage strain components and area of the plastic deformed zone, caused by welding. The calculated strains are then transferred to the global finite element model in order to predict the distortions and stresses in the structure after every welding stage, as well as their final state. The consideration of welding scenarios, weld sequence, clamping conditions and the assembling stages is done by taking into account the intermediate variation of the strain state during the manufacturing steps. The article gives the theoretical basis of the analytical model. The consideration of the essential physical relations is put into discussion. The application of the model is illustrated on complex structures. Its reliability and practicability are demonstrated by means of a validation study.}, language = {en} } @misc{PasternakKrausche, author = {Pasternak, Hartmut and Krausche, Thomas}, title = {Details and assembly of two cladded double curved cable net roofs}, series = {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}, journal = {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}, editor = {Zingoni, Alphose}, publisher = {Taylor \& Francis Group}, address = {London}, isbn = {978-1-138-38696-9}, pages = {896 -- 901}, language = {en} } @misc{LaunertLiPasternak, author = {Launert, Benjamin and Li, Zheng and Pasternak, Hartmut}, title = {Development of a new method for the direct numerical consideration of welding effects in the component design of welded plate girders}, series = {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}, journal = {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}, editor = {Zingoni, Alphose}, publisher = {Taylor \& Francis Group}, address = {London}, isbn = {978-1-138-38696-9}, pages = {1143 -- 1147}, language = {en} } @misc{LiPasternakCiupack, author = {Li, Zheng and Pasternak, Hartmut and Ciupack, Yvonne}, title = {Artificial neural network prediction of bearing capacity of welded columns based on simplified welding simulations}, series = {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}, journal = {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}, editor = {Zingoni, Alphose}, publisher = {Taylor \& Francis Group}, address = {London}, isbn = {978-1-138-38696-9}, pages = {1219 -- 1223}, language = {en} } @misc{KasperAlbiezUmmenhoferetal., author = {Kasper, Yann and Albiez, Matthias and Ummenhofer, Thomas and Ciupack, Yvonne and Ledecky, Lukas and Pasternak, Hartmut and Geßler, Achim and Feldmann, Markus}, title = {Application of carbon fibre composite materials for the rehabilitation of fatigue damaged steel structures}, series = {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}, journal = {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}, editor = {Zingoni, Alphose}, publisher = {Taylor \& Francis Group}, address = {London}, isbn = {978-1-138-38696-9}, pages = {2148 -- 2153}, language = {en} } @misc{StapelfeldLaunertPasternaketal., author = {Stapelfeld, Christoph and Launert, Benjamin and Pasternak, Hartmut and Doynov, Nikolay and Michailov, Vesselin}, title = {Improve load capacity calculations by considering realistic imperfections induced by welding for plates and shells}, series = {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}, journal = {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}, publisher = {CRC Press}, address = {Boca Raton}, isbn = {978-0-367-33503-8}, pages = {1059 -- 1067}, language = {en} } @misc{ShoushtarianMofradShlychkovaCiupacketal., author = {Shoushtarian Mofrad, Ashkan and Shlychkova, Darita and Ciupack, Yvonne and Pasternak, Hartmut}, title = {FE Modelling of Sandwich Panels with Screwed Joint at Elevated Temperatures}, series = {XVIII ANNIVERSARY INTERNATIONAL SCIENTIFIC CONFERENCE BY CONSTRUCTION AND ARCHITECTURE VSU'2018, At Sofia, Bulgaria}, journal = {XVIII ANNIVERSARY INTERNATIONAL SCIENTIFIC CONFERENCE BY CONSTRUCTION AND ARCHITECTURE VSU'2018, At Sofia, Bulgaria}, pages = {6}, abstract = {Understanding and predicting sandwich structure behavior in fire has been of particular interest to researchers for a long time. Sandwich panel joints are playing an important role since they not only connect sandwiches to a bearing structure, but also play a key role in stabilization of the whole building. This paper presents an investigation of a sandwich panel behavior. The sandwich panel consist of two steel layers and PIR core between them and is connected to a HEA 160 flange with the help of a screw. Using ABAQUS software, this connection is modelled and deformation fields with temperature distribution area are analyzed. The modelling process includes many stages associated with each other: static, heat transfer and sequential analysis that includes both previous analyses.}, language = {en} } @misc{ShlychkovaPasternak, author = {Shlychkova, Darita and Pasternak, Hartmut}, title = {Numerical analysis and laboratory experiments of lightweight structured sandwich beams made of steel}, series = {Proceedings VII International Scientific Conference VSU 2017, 8-9 Juni 2017, Sofia, Bulgaria}, volume = {Volume 1}, journal = {Proceedings VII International Scientific Conference VSU 2017, 8-9 Juni 2017, Sofia, Bulgaria}, address = {Sofia, Bulgaria}, issn = {1314-071X}, pages = {252 -- 260}, abstract = {Using special technology it is possible to produce thin steel plates with a 3-D structure - hexagonal staggered pattern. Such sheets find a range of application in automotive and aerospace industry. The question is: Can we use those sheets also for building applications? Therefore their behaviour under external loads has to be studied. As an example beams with C-section made of structured sheets under concentrated force in the middle of the upper flange are investigated. This article provides information about load capacity of beams, assembled from structured plates with different thickness. Using Abaqus software beams were modelled and deformation fields for each of them were analyzed. To compare computer calculations with actual results, real sized beams made of structured sheets were constructed in laboratory and bending tests were conducted.}, language = {en} } @misc{PasternakLiStapelfeldetal., author = {Pasternak, Hartmut and Li, Zheng and Stapelfeld, Christoph and J{\"a}ger-Ca{\~n}{\´a}s, Andreas and Launert, Benjamin}, title = {Considering realistic weld imperfections in load bearing capacity calculations of ring-stiffened shells using the analytical numerical hybrid model}, series = {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}, journal = {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}, edition = {1st Edition}, publisher = {CRC Press}, address = {London}, isbn = {978-0-429-32024-8}, doi = {10.1201/9780429320248}, pages = {882 -- 889}, language = {en} } @misc{JaegerCanasLiPasternak, author = {J{\"a}ger-Ca{\~n}{\´a}s, Andreas and Li, Zheng and Pasternak, Hartmut}, title = {Axial buckling behavior of welded ring-stiffened shells}, series = {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}, journal = {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}, edition = {1st Edition}, publisher = {CRC Press}, address = {London}, isbn = {978-0-429-32024-8}, doi = {10.1201/9780429320248}, pages = {556 -- 563}, language = {en} } @misc{LoebjinskiRugPasternak, author = {Loebjinski, Maria and Rug, Wolfgang and Pasternak, Hartmut}, title = {The influence of an improved strength grading in situ on modelling timber strength properties}, series = {Proceedings of the International Conference on Structural Health Assessment of Timber Structures, SHATiS´2019}, journal = {Proceedings of the International Conference on Structural Health Assessment of Timber Structures, SHATiS´2019}, publisher = {Universidade do Minho Departamento de Engenharia Civi}, address = {Guimar{\~a}es, Portugal}, isbn = {978-989-54496-2-0}, pages = {619 -- 628}, language = {en} } @misc{LoebjinskiLinkeRugetal., author = {Loebjinski, Maria and Linke, Gunter and Rug, Wolfgang and Pasternak, Hartmut}, title = {Redevelopment of a wooden roof construction under preservation order}, series = {Proceedings of the International Conference on Structural Health Assessment of Timber Structures, SHATiS´2019}, journal = {Proceedings of the International Conference on Structural Health Assessment of Timber Structures, SHATiS´2019}, publisher = {Universidade do Minho Departamento de Engenharia Civi}, address = {Guimar{\~a}es, Portugal}, isbn = {978-989-54496-2-0}, pages = {912 -- 921}, language = {en} } @misc{LoebjinskiLinkeRugetal., author = {Loebjinski, Maria and Linke, Gunter and Rug, Wolfgang and Pasternak, Hartmut}, title = {Evaluation of existing timber structures - Current standards for the assessment and evaluation in Germany and Europe}, series = {Proceedings of the International Conference on Structural Health Assessment of Timber Structures, SHATiS´2019}, journal = {Proceedings of the International Conference on Structural Health Assessment of Timber Structures, SHATiS´2019}, publisher = {Universidade do Minho Departamento de Engenharia Civi}, address = {Guimar{\~a}es, Portugal}, isbn = {978-989-54496-2-0}, pages = {884 -- 893}, language = {en} } @misc{FeldmannUmmenhoferGessleretal., author = {Feldmann, Markus and Ummenhofer, Thomas and Geßler, Achim and Pasternak, Hartmut and Kasper, Yann and Albiez, Matthias and Ciupack, Yvonne and Ledecky, Lukas}, title = {Einsatz geklebter CFK-Lamellen zur Verst{\"a}rkung erm{\"u}dungsgesch{\"a}digter Stahlkonstruktionen}, series = {Schweissen und Schneiden: Fachzeitschrift f{\"u}r Schweißen und verwandte Verfahren}, journal = {Schweissen und Schneiden: Fachzeitschrift f{\"u}r Schweißen und verwandte Verfahren}, number = {11}, issn = {0036-7184}, pages = {738 -- 745}, language = {de} } @misc{CiupackLedeckyKasperetal., author = {Ciupack, Yvonne and Ledecky, Lukas and Kasper, Yann and Geßler, Achim and Albiez, Matthias and Pasternak, Hartmut and Ummenhofer, Thomas and Feldmann, Markus}, title = {Strengthening of steel structures with fatigue cracks using adhesively bonded non-prestressed and prestressed CFRP lamellas}, series = {The 13th International Conference MODERN BUILDING MATERIALS, STRUCTURES AND TECHNIQUES, 16-17 May 2019, Vilnius, Lithuania Vilnius Gediminas Technical University}, journal = {The 13th International Conference MODERN BUILDING MATERIALS, STRUCTURES AND TECHNIQUES, 16-17 May 2019, Vilnius, Lithuania Vilnius Gediminas Technical University}, editor = {Juozapaitis, Algirdas and Daniūnas, Alfonsas and Juknevičius, Linas}, isbn = {978-609-476-197-3}, issn = {2029-9915}, doi = {10.3846/mbmst.2019.068}, pages = {252 -- 260}, abstract = {In comparison to classic strengthening methods of fatigue-damaged steel structures, adhesively bonded CFRP lamellas show several advantages. Compared to bolted reinforcement measures and the drilling of the crack tip, crosssectional weakening is avoided. Heat-induced, negatively acting residual stresses and distortions, usually occurring during repair welding, can also be excluded. Therefore, the effectiveness of adhesively bonded CFRP lamellas to enhance the remaining lifetime of fatigue damaged steel structures is examined in a German research project. Selected results are presented in this paper. To characterize the steel, CFRP and adhesive materials, different tests on small scale specimens are carried out. With the help of fatigue tests on CT-samples the remaining fatigue lifetimes of specimens strengthened with adhesively bonded CFRP lamellas is compared to the remaining lifetimes of specimens strengthened by established methods such as drilling the crack tip and repair welding. Based on the evaluation of the crack propagation after the rehabilitation measures, the great potential of adhesively bonded CFRP reinforcements can be deduced. By prestressing the lamellas, the remaining lifetime can generally be increased further. The combination of adhesively bonded CFRP lamellas together with established rehabilitation methods shows a particularly high positive influence on the remaining lifetime of the CT-specimens.}, language = {en} } @misc{LoebjinskiRugPasternak, author = {Loebjinski, Maria and Rug, Wolfgang and Pasternak, Hartmut}, title = {The Influence of Improved Strength Grading In Situ on Modelling Timber Strength Properties}, series = {Buildings : open access journal}, volume = {10}, journal = {Buildings : open access journal}, number = {2}, issn = {2075-5309}, doi = {10.3390/buildings10020030}, pages = {15}, language = {en} } @misc{SternsdorffCiupackYilmazetal., author = {Sternsdorff, Florian and Ciupack, Yvonne and Yilmaz, Emre Mehmet and Pasternak, Hartmut and Vayas, Ioannis}, title = {Investigations on beam-to-column connections reinforced with adhesively bonded CFRP lamellas}, series = {7th International Conference Civil Engineering - Science and Practice (GNP), Kolašin, 10.-14. March 2020, Book of abstracts}, journal = {7th International Conference Civil Engineering - Science and Practice (GNP), Kolašin, 10.-14. March 2020, Book of abstracts}, pages = {8}, abstract = {Against the background of the earthquake-proof design of steel structures, it makes sense to use structures with sufficient ductility and energy dissipation capacity. The joints are often a weak point in such systems. Methods for reinforcing beam-to-column connections with the aid of adhesively bonded CFRP products are the subject of the work. Advantages of such reinforcement methods are the avoidance of residual stresses (compared to welded steel lamellas), avoidance of cross-sectional weakening (in comparison to bolted solutions) and, above all, the possibility of retrofitting existing steel structures.}, language = {en} } @misc{PasternakKrausche, author = {Pasternak, Hartmut and Krausche, Thomas}, title = {Design, Construction and Assembly of two Membrane-Cladded Double-Curved Net Roofs}, series = {7th International Conference Civil Engineering - Science and Practice (GNP), Kolašin, 10-14 March 2020, Book of abstracts}, journal = {7th International Conference Civil Engineering - Science and Practice (GNP), Kolašin, 10-14 March 2020, Book of abstracts}, pages = {8}, language = {en} } @misc{ShoushtarianMofradShlychkovaCiupacketal., author = {Shoushtarian Mofrad, Ashkan and Shlychkova, Darita and Ciupack, Yvonne and Pasternak, Hartmut}, title = {Study of Bending, Translational and Torsional Stiffness of Sandwich Panels in Fire}, series = {7th International Conference Civil Engineering - Science and Practice (GNP), Kolašin, 10-14 March 2020, Book of abstracts}, journal = {7th International Conference Civil Engineering - Science and Practice (GNP), Kolašin, 10-14 March 2020, Book of abstracts}, pages = {8}, language = {en} } @misc{KasperAlbiezCiupacketal., author = {Kasper, Yann and Albiez, Matthias and Ciupack, Yvonne and Geßler, Achim and Ummenhofer, Thomas and Pasternak, Hartmut and Feldmann, Markus}, title = {Verst{\"a}rkung von erm{\"u}dungsbeanspruchten Stahlbauteilen mit aufgeklebten CFK-Lamellen - Teil 1: Grundlagen}, series = {Bauingenieur}, volume = {95}, journal = {Bauingenieur}, number = {3}, issn = {0005-6650}, pages = {79 -- 84}, language = {de} } @misc{KasperAlbiezCiupacketal., author = {Kasper, Yann and Albiez, Matthias and Ciupack, Yvonne and Geßler, Achim and Ummenhofer, Thomas and Pasternak, Hartmut and Feldmann, Markus}, title = {Verst{\"a}rkung von erm{\"u}dungsbeanspruchten Stahlbauteilen mit aufgeklebten CFK-Lamellen - Teil 2: Experimentelle Rissfortschrittsuntersuchungen}, series = {Bauingenieur}, volume = {95}, journal = {Bauingenieur}, number = {5}, issn = {0005-6650}, pages = {166 -- 173}, language = {de} } @misc{DongLiPasternaketal., author = {Dong, Jiwu and Li, Zheng and Pasternak, Hartmut and Ciupack, Yvonne}, title = {Reinforcement of Fatigue Damaged Steel Structures Using CFRP Lamellas - Part 3: Numerical Simulation}, series = {Bauingenieur}, volume = {96}, journal = {Bauingenieur}, number = {10}, issn = {0005-6650}, pages = {362 -- 368}, language = {en} } @misc{PasternakCiupack, author = {Pasternak, Hartmut and Ciupack, Yvonne}, title = {Use of CFRP for the Rehabilitation of Fatigue Damaged Steel Structures - Only a Nice Idea?}, series = {XX International Scientific Conference VSU'2020 on Construction and Architecture Book of Abstracts}, journal = {XX International Scientific Conference VSU'2020 on Construction and Architecture Book of Abstracts}, editor = {Georgiev, Vanyo and Stoynova, Iliana}, issn = {1314-071X}, pages = {9}, language = {en} } @misc{KasperAlbiezUmmenhoferetal., author = {Kasper, Yann and Albiez, Matthias and Ummenhofer, Thomas and Mayer, Christoph and Meier, Tobias and Choffat, Fabien and Ciupack, Yvonne and Pasternak, Hartmut}, title = {Application of toughened epoxy-adhesives for strengthening of fatigue-damaged steel structures}, series = {Construction and Building Materials}, volume = {275}, journal = {Construction and Building Materials}, issn = {0950-0618}, doi = {10.1016/j.conbuildmat.2020.121579}, pages = {15}, language = {en} } @misc{LiPasternak, author = {Li, Zheng and Pasternak, Hartmut}, title = {Statistischer Maßstabseffekt und seine Bedeutung f{\"u}r die Zuverl{\"a}ssigkeit im Stahlbau,Teil 1 - Modell und Versuch}, series = {Bautechnik}, volume = {97}, journal = {Bautechnik}, number = {11}, doi = {10.1002/bate.202000030}, pages = {766 -- 772}, language = {de} } @misc{LiLoebjinskiPasternak, author = {Li, Zheng and Loebjinski, Maria and Pasternak, Hartmut}, title = {Statistischer Maßstabseffekt und seine Bedeutung f{\"u}r die Zuverl{\"a}ssigkeit im Stahlbau, Teil 2- Zuverl{\"a}ssigkeitsanalyse}, series = {Bautechnik}, volume = {97}, journal = {Bautechnik}, number = {11}, doi = {10.1002/bate.202000031}, pages = {773 -- 779}, language = {de} } @misc{LiPasternakRobra, author = {Li, Zheng and Pasternak, Hartmut and Robra, J{\"o}rgen}, title = {Tragverhalten von Wellstegtr{\"a}gern mit kreisf{\"o}rmigem {\"O}ffnungskranz}, series = {Bauingenieur}, volume = {96}, journal = {Bauingenieur}, number = {4}, issn = {0005-6650}, doi = {10.37544/0005-6650-2021-04-50}, pages = {114 -- 120}, language = {de} } @book{PasternakStapelfeldLaunertetal., author = {Pasternak, Hartmut and Stapelfeld, Christoph and Launert, Benjamin and Michailov, Vesselin and Doynov, Nikolay}, title = {Ermittlung der Tragf{\"a}higkeit neuartiger st{\"a}hlerner Schalenbauwerke unter realit{\"a}tsnaher Ber{\"u}cksichtigung des Schweißverzugs}, publisher = {Forschungsvereinigung Stahlanwendung e. V.}, address = {D{\"u}sseldorf}, isbn = {978-3-946885-89-4}, pages = {227}, language = {de} } @misc{SternsdorffCiupackPasternak, author = {Sternsdorff, Florian and Ciupack, Yvonne and Pasternak, Hartmut}, title = {Experimental Investigations on Innovative Crack Repair Methods and reinforcing Steel Structures with Adhesivly Bonded CFRP - Lamellas}, series = {Engineering Structures and Technologies}, volume = {13}, journal = {Engineering Structures and Technologies}, number = {1}, issn = {2029-882X}, doi = {10.3846/est.2021.15036}, pages = {1 -- 6}, language = {en} } @misc{WangLiRobraetal., author = {Wang, Jian and Li, Zheng and Robra, J{\"o}rgen and Pasternak, Hartmut and Euler, Mathias}, title = {Investigation on Shear Buckling of Corrugated Web Beams with Reinforced Web Openings}, series = {ce/papers}, volume = {5}, journal = {ce/papers}, number = {4}, issn = {2509-7075}, doi = {10.1002/cepa.1800}, pages = {628 -- 634}, abstract = {Corrugated web beams are welded I-sections with thin-walled sinusoidal corrugated webs and flanges made of wide flat steel that have been developed as an alternative to steel girders with flat webs. In comparison with hot-rolled or welded I-beams with flat webs, corrugated web beams are connected with considerable material savings and fully automated production. Assuming the same load-bearing capacity, corrugated web beams are lighter than those with a flat web, since the corrugated web beams can often be loaded up to their plastic resistance without reinforcement of the web. The research on the load-bearing behavior of corrugated web beams without web openings is relatively mature. However, the resistance of corrugated web beams with reinforced web openings, as they are often used in buildings for installations, has not well experimentally been investigated, yet. This paper deals with the shear resistance of corrugated web beams with reinforced square web openings. Three specimens of different geometry with two square web openings were tested. The experiments are compared with a Finite Element Analysis by Abaqus® and with an analytical model allowing simplified calculation. Both models can relatively accurately calculate the shear resistance. The experimental and numerical results show that the increase of the shear resistance of perforated corrugated web beams depends on the wall-thickness and the steel grade of the web opening reinforcement.}, language = {en} } @misc{LiZhangShietal., author = {Li, Zheng and Zhang, Qiulei and Shi, Fei and Wang, Jian and Pasternak, Hartmut}, title = {Geometric Properties of Steel Components with Stability and Fatigue Risks Using 3D-Laser-Scanning}, series = {Buildings}, volume = {14}, journal = {Buildings}, number = {1}, issn = {2075-5309}, doi = {10.3390/buildings14010168}, abstract = {Nowadays, 3D laser scanning technology is extensively employed in laboratory investigations of steel structural components, providing accurate geometric dimensions to reduce uncertainties caused by indeterminate geometry in experimental results. It is often used in conjunction with the Finite Element (FE) Method and analytical solutions, which are more accurate deterministic operators in the research on steel structures. However, establishing a common methodological framework for transferring or mapping 3D-scanned information into finite element models for complex steel structures with stability and fatigue risks remains an ongoing task. In light of this, this study has developed a 3D scanning platform capable of obtaining accurate geometric dimensions for various types of steel components. Different coordinate systems and point cloud mapping algorithms have been established for different types of components to construct actual finite element models with initial imperfections. The feasibility of the self-developed 3D scanning platform and finite element modelling has been validated through three experimental cases: weld details, steel girders, and cylindrical shells. The research findings demonstrate that the captured point cloud can be automatically processed and corrected using the developed algorithm. The scanned data can then be input into the numerical model using various mapping algorithms tailored to the specific geometric properties of the specimens. The differences between the experimental test results and the simulated results obtained from the 3D-scanned finite element models remain within a small range. The self-developed 3D scanning platform and finite element modelling technique effectively capture the actual dimensions of different steel components, enabling the prediction of their stability and fatigue risks through numerical simulations.}, language = {en} } @misc{WangEulerPasternaketal., author = {Wang, Jian and Euler, Mathias and Pasternak, Hartmut and Li, Zheng and Krausche, Thomas and Launert, Benjamin}, title = {Bending capacity of single and double-sided welded I-section girders: Part 1: Experimental investigations}, series = {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}, journal = {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}, publisher = {CRC Press}, address = {Boca Raton}, isbn = {978-1-00-334845-0}, doi = {10.1201/9781003348443-159}, pages = {975 -- 980}, abstract = {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.}, language = {en} } @misc{LiXuGeissleretal., author = {Li, Zheng and Xu, Siying and Geißler, Karsten and Wang, Jian and Pasternak, Hartmut}, title = {Developed numerical Analysis of Residual Stress caused by Welding and Cutting in Steel Structures}, series = {ce/papers}, volume = {6}, journal = {ce/papers}, number = {3-4}, issn = {2509-7075}, doi = {10.1002/cepa.2601}, pages = {1507 -- 1512}, abstract = {The welding and flame-cutting process in the steel construction are commonly used, especially for the bridge structure. Some experiments about welding and cutting have been done separately by some researchers. The results from the experiments were also compared with the results from the numerical simulation under 3D or 2D models. The agreements between those results are as good as they predicted. Therefore, the numerical simulation is a better way to analyze the quality of the steel construction after welding and cutting without time-consuming and a large amount of cost. But there are only a few research about the numerical simulation and the some of them are aimed to verify the experiments. In this study, the calculation about the residual stresses after welding and thermo-cutting are considered from 3D-model into 2D-Model. The heat source model is simply regarded as curves of time and welding energy with the algorithm methods. And no matter the change of the parameters of the model and the heat source, the heat transfer and the residual stresses can be calculated with the 2D models as fast as possible. By the means of the finite element software Abaqus, the I-profiles are easy to receive the job results with the input parameters. The influence of the welding and cutting process are visual and direct.}, language = {en} } @misc{WangLiPasternaketal., author = {Wang, Jian and Li, Zheng and Pasternak, Hartmut and Euler, Mathias}, title = {Shear Buckling Behavior of Tapered Steel Plate Girders with Sinusoidally Corrugated Webs}, series = {ce/papers}, volume = {6}, journal = {ce/papers}, number = {3-4}, issn = {2509-7075}, doi = {10.1002/cepa.2534}, pages = {1787 -- 1792}, language = {en} } @misc{WangLiPasternaketal., author = {Wang, Jian and Li, Zheng and Pasternak, Hartmut and Euler, Mathias}, title = {Querkrafttragf{\"a}higkeit von Wellstegtr{\"a}gern mit versteiften quadratischen Steg{\"o}ffnungen}, series = {Bauingenieur}, volume = {98}, journal = {Bauingenieur}, number = {11}, issn = {0005-6650}, doi = {10.37544/0005-6650-2023-11-31}, pages = {343 -- 353}, abstract = {Die Ergebnisse aus drei Traglastversuchen und einer umfangreichen numerischen Parameterstudie (FE-Berechnungen) zum Tragverhalten von Wellstegtr{\"a}gern mit quadratischen Steg{\"o}ffnungen werden vorgestellt. Es werden versteifte Steg{\"o}ffnungen mit einem umlaufenden Versteifungskranz betrachtet. In der Parameterstudie werden die Einfl{\"u}sse der Steg{\"o}ffnungsgeometrie, der Tr{\"a}gergeometrie und der Position der Steg{\"o}ffnung auf die Querkrafttragf{\"a}higkeit der Wellstegtr{\"a}ger untersucht.}, language = {de} }