@misc{LiLaunertPasternak, author = {Li, Zheng and Launert, Benjamin and Pasternak, Hartmut}, title = {Application of the stochastic finite element method in welding simulation}, series = {Welding in the World}, volume = {62}, journal = {Welding in the World}, number = {5}, issn = {0043-2288}, doi = {10.1007/s40194-018-0596-4}, pages = {905 -- 912}, abstract = {Due to the uncertain microscopic structure of the material, the strength of the material exhibits strong randomness. This randomness results in uncertain response of the structure in the sequentially coupled thermal-mechanical analysis by welding simulation. Because of the limitations of deterministic welding simulation, the stochastic finite element method with random field will be introduced into the welding simulation, so that the welded structure can be more accurately calculated in the stability and reliability structural analysis. Particularly, it is necessary to propose reasonable distributions of residual stress from welding simulations based on statistical and reliability theories. This paper is intended to implement the stochastic finite element method in the welding simulation using a general-purpose simulation program and to demonstrate the potential of the proposed approach. Furthermore, the statistical distribution function of the welding simulation response is obtained by maximum entropy fitting method. Then, a numerical example is presented by the proposed method.}, language = {en} } @inproceedings{GarifullinLaunertHeinisuoetal., author = {Garifullin, Marsel and Launert, Benjamin and Heinisuo, Markku and Pasternak, Hartmut and Mela, Kristo and Pajunen, Sami}, title = {Effect of Welding Residual Stresses on Behavior of Tubular T Joints}, series = {17th International Conference on Computing in Civil and Building Engineering}, booktitle = {17th International Conference on Computing in Civil and Building Engineering}, pages = {8}, abstract = {Welded tubular joints are widely used in structural engineering due to their excellent resistance and stiffness, as well as simple connection. However, the welding process induces residual stresses in the welding area that can affect the structural behavior of joints. Currently very few papers investigate welding residual stresses in relation to tubular joints. This paper develops a finite element model of rectangular hollow section T joints considering welding residual stresses. Attention is paid particularly to welding sequences. The developed model is used to evaluate the effect of welding residual stresses on the resistance and initial stiffness of tubular joints. The results show that welding residual stresses increase the plastic resistance of rectangular hollow section joints under in-plane bending and axial brace loading.}, language = {en} } @inproceedings{ZivaljevicLuxorPasternak, author = {Zivaljevic-Luxor, Natasa and Pasternak, Hartmut}, title = {Roofs for archaeological sites integration into public space of metropolitan area}, series = {International Scientific Conference, Nis, Serbia, 31.08-01-09.2018}, booktitle = {International Scientific Conference, Nis, Serbia, 31.08-01-09.2018}, pages = {10}, language = {en} } @inproceedings{JaegerCanasPasternak, author = {J{\"a}ger-Ca{\~n}{\´a}s, Andreas and Pasternak, Hartmut}, title = {On the buckling behavior of ring-stiffened shells under axial compression}, series = {8th International Conference on Thin-Walled Structures, ICTWS 2018, Lisbon, Portugal, July 24-27, 2018}, booktitle = {8th International Conference on Thin-Walled Structures, ICTWS 2018, Lisbon, Portugal, July 24-27, 2018}, pages = {13}, language = {en} } @incollection{LoebjinskiRugPasternak, author = {Loebjinski, Maria and Rug, Wolfgang and Pasternak, Hartmut}, title = {Aktuelle Normen f{\"u}r den Bestandsbau mit Holz und beispielhafte Zuverl{\"a}ssigkeitsuntersuchungen}, series = {Holzbau im Bestand - historische Holztragwerke : Beispiele f{\"u}r substanzschonende Erhaltung}, booktitle = {Holzbau im Bestand - historische Holztragwerke : Beispiele f{\"u}r substanzschonende Erhaltung}, editor = {Rug, Wolfgang}, publisher = {Beuth Verlag}, address = {Berlin}, isbn = {978-3-410-28175-7}, pages = {162 -- 192}, language = {de} } @inproceedings{LoebjinskiRugPasternak, author = {Loebjinski, Maria and Rug, Wolfgang and Pasternak, Hartmut}, title = {Possibilities for a modification of partial safety factors for existing timber structures}, series = {World Conference on Timber Engineering, Seoul, 20 - 23 Aug 2018}, booktitle = {World Conference on Timber Engineering, Seoul, 20 - 23 Aug 2018}, pages = {7}, language = {en} } @inproceedings{PartovPasternakGrekovetal., author = {Partov, Doncho and Pasternak, Hartmut and Grekov, Petar and Nikolov, Radoslav and Dimitrova, Antoaneta}, title = {About the Theory of Orthotropic Steel Plate Established by Wilhelm Cornelius and its Application for Analysis of Two Steel Bridges With Orthotropic Decks in Varna}, series = {X Jubilee International Scientific Conference „Civil Engineering Design and Construction", Sept. 20-22, 2018, Varna, Bulgaria}, booktitle = {X Jubilee International Scientific Conference „Civil Engineering Design and Construction", Sept. 20-22, 2018, Varna, Bulgaria}, pages = {469 -- 481}, language = {en} } @inproceedings{LoebjinskiKoehlerRugetal., author = {Loebjinski, Maria and K{\"o}hler, Jochen and Rug, Wolfgang and Pasternak, Hartmut}, title = {Development of an optimization-based and practice orientated assessment scheme for the evaluation of existing timber structures}, series = {Life-Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision}, booktitle = {Life-Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision}, editor = {Caspeele, Robby and Taerwe, Luc and Frangopol, Dan M.}, publisher = {Taylor \& Francis Group}, address = {London}, isbn = {978-1-138-62633-1}, pages = {353 -- 360}, language = {en} } @inproceedings{StapelfeldLaunertPasternaketal., author = {Stapelfeld, Christoph and Launert, Benjamin and Pasternak, Hartmut and Doynov, Nikolay and Michailov, Vesselin}, title = {Strength Calculation of Stiffened Structures Taking Into Consideration Realistic Weld Imperfections}, series = {European Conference on Residual Stresses 2018, ECRS-10, Leuven, Belgium, 11-14th September, 2018}, booktitle = {European Conference on Residual Stresses 2018, ECRS-10, Leuven, Belgium, 11-14th September, 2018}, editor = {Seefeldt, Marc}, publisher = {Materials Research Forum LLC}, address = {Millersville, PA}, isbn = {978-1-945291-88-3}, doi = {10.21741/9781945291890-39}, pages = {245 -- 250}, abstract = {The topic of this article is the application of an analytical numerical hybrid model for a realistic prediction of imperfections induced by welds. At the beginning, the analytical model, its physical basis as well as the physical interrelationships are explained. This is followed by the explanation of the coupling procedure between the analytical model and the numerical calculation. Afterwards, the coupled hybrid model is applied on the investigated stiffened curved structure for the determination of the weld imperfections. An ultimate load analysis gives information about the load carrying behavior under axial loading. The results are compared against the traditional approach using eigenmode-based imperfections. The comparison underlines the potential additional utilization of load bearing capacity by this new approach.}, language = {en} } @misc{ZebingerGieratPasternaketal., author = {Zebinger, Markus and Gierat, Marek and Pasternak, Hartmut and Krausche, Thomas}, title = {Das Seilnetzdach der Schierker Feuerstein Arena im Harz Teil 2: Herstellung, Montage und Schweißsimulation}, series = {Bauingenieur}, volume = {93}, journal = {Bauingenieur}, number = {10}, issn = {0005-6650}, pages = {383 -- 391}, abstract = {Die Stadt Wernigerode in Sachsen-Anhalt errichtete im Ortsteil Schierke eine Multifunktionsarena. Am Fuße des Brockens, dem h{\"o}chsten Berg des Harzes und ganz Norddeutschlands gelegen, f{\"u}gt sich die offene {\"U}berdachung 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 {\"u}berdachte Kunsteisbahn und im Sommer als Fl{\"a}che f{\"u}r Konzerte, Auff{\"u}hrungen und Sportveranstaltungen genutzt werden kann. Eine ganz besondere Herausforderung war die Herstellung und Montage des circa 190m langen geschweißten Stahlrandtr{\"a}gers. Der Hohlkasten besteht aus vier doppelt gekr{\"u}mmten Blechen und lagert an lediglich zwei Fußpunkten auf. Der zweite Teil des Beitrags befasst sich mit Schweißeigenspannungen an einem ausgew{\"a}hlten Querschnitt der {\"U}berdachung.}, language = {de} } @misc{StapelfeldLaunertPasternaketal., author = {Stapelfeld, Christoph and Launert, Benjamin and Pasternak, Hartmut and Doynov, Nikolay and Michailov, Vesselin}, title = {Traglastberechnung versteifter Platten und Schalen unter Ber{\"u}cksichtigung realer Schweißimperfektionen}, series = {Bauingenieur}, volume = {93}, journal = {Bauingenieur}, number = {10}, issn = {0005-6650}, pages = {403 -- 411}, abstract = {Imperfektionen, die bei Traglastberechnungen Ber{\"u}cksichtigung finden m{\"u}ssen, haben ihre Ursachen in Herstellungs- und Fertigungstoleranzen oder werden durch das Schweißen und den damit zumeist einhergehenden Nachbehandlungen in den Bauteilen hervorgerufen. Durch die W{\"a}rmewirkung des Schweißens entstehen sowohl sehr große Verformungen als auch signifikante Zug und Druckspannungen. Der strukturelle und geometrische Imperfektionsgrad wird somit maßgeblich von der Anzahl und der Lage der Schweißn{\"a}hte sowie den Schweißparametern bestimmt. F{\"u}r die Ber{\"u}cksichtigung in Traglastberechnungen ist ein physikalisch fundiertes Modell erforderlich, welches die Schweißimperfektionen schnell und pr{\"a}zise berechnet. Das gekoppelte analytisch numerische Hybridmodell erf{\"u}llt diese Kriterien. Die mathematischen Grundlagen des analytischen Modells sowie die Kopplung mit der numerischen Finite-Elemente-Berechnung werden eingangs vorgestellt und die Anwendung zur Berechnung von Verz{\"u}gen an einer Schiffsektion demonstriert. Darauffolgend wird das Hybridmodell an einer eben und einer gekr{\"u}mmten versteiften Platte zur Berechnung der Schweißimperfektionen angewendet. Anschließende Traglastberechnungen sowie der Vergleich mit den Ergebnissen unter der Annahme einer geometrischen Ersatzimperfektion in Form des kritischsten Eigenwerts gibt Auskunft dar{\"u}ber, welches Potenzial die realit{\"a}tsnahe direkte Ber{\"u}cksichtigung von Schweißimperfektionen birgt.}, language = {de} }