TY - GEN A1 - Fritzsche, Sebastian A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Experimental characterisation of structured sheet metals T2 - Key Engineering Materials Y1 - 2011 SN - 1013-9826 SN - 1662-9795 VL - 473 SP - 404 EP - 411 ER - TY - CHAP A1 - Dreibati, Ossama A1 - Zhang, Wei A1 - Wolf, Matthias A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Thermo-mechanical properties of refractory ceramic for the numerical simulation of their thermo-shock behaviour Y1 - 2011 ER - TY - CHAP A1 - Dreibati, Ossama A1 - Ossenbrink, Ralf A1 - Doynov, Nikolay A1 - Michailov, Vesselin T1 - Physical and numerical simulation of thermo-mechanical properties in the weld heat affected zone of an AlMgSi-alloy T2 - THERMEC 2011, International Conference on Processing & Manufacturing of Advanced Materials, processing, fabrication, properties, applications, August 1 - 5, 2011, Quebec City, Canada, Vol. 2 Y1 - 2011 SP - 1491 EP - 1496 PB - TTP, Trans Tech Publ. CY - Durnten-Zurich [u.a.] ER - TY - CHAP A1 - Dreibati, Ossama A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Hydrogen charging of high strength steel specimens and physical simulation of cold cracking under laser beam welding conditions T2 - THERMEC 2011, International Conference on Processing & Manufacturing of Advanced Materials, processing, fabrication, properties, applications, August 1 - 5, 2011, Quebec City, Canada, Vol. 2 Y1 - 2012 SN - 978-3-0-3785-303-0 SP - 1391 EP - 1396 PB - TTP, Trans Tech Publ. CY - Durnten-Zurich [u.a.] ER - TY - CHAP A1 - Kornienko, Elena A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Investigation of corrosion behaviour of structured sheet metals by salt spray test T2 - Proceedings of International Conference on Innovative Technologies, IN-TECH, 01.09.2011 to 03.09.2011, Bratislava, Slovakia Y1 - 2011 SP - 308 EP - 311 ER - TY - CHAP A1 - Sasse, Ina A1 - Schleuß, Leander A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Cutting of structured sheet metals with high power fiber laser T2 - Proceedings of International Conference on Innovative Technologies, IN-TECH, 01.09.2011 to 03.09.2011, Bratislava, Slovakia Y1 - 2011 SP - 485 EP - 488 ER - TY - CHAP A1 - Malikov, Viatcheslav A1 - Ossenbrink, Ralf A1 - Viehweger, Bernd A1 - Michailov, Vesselin T1 - Flat hemming of structured sheet metals T2 - Proceedings of International Conference on Innovative Technologies, IN-TECH, 01.09.2011 to 03.09.2011, Bratislava, Slovakia KW - hemming KW - structured sheet metal KW - FE analysis Y1 - 2011 ER - TY - GEN A1 - Malikov, Viatcheslav A1 - Ossenbrink, Ralf A1 - Viehweger, Bernd A1 - Michailov, Vesselin T1 - Experimental investigation and analytical calculation of the bending force for air bending of structured sheet metals T2 - Advanced Materials Research KW - air bending KW - structured sheet metal KW - bending force Y1 - 2012 SN - 1022-6680 VL - 418-420 SP - 1294 EP - 1300 ER - TY - GEN A1 - Kornienko, Elena A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Corrosion properties of structured sheet metals in salt environment T2 - Engineering Review Y1 - 2011 SN - 1330-9587 VL - 31 IS - 2 SP - 97 EP - 104 ER - TY - GEN A1 - Dreibati, Ossama A1 - Ossenbrink, Ralf A1 - Doynov, Nikolay A1 - Michailov, Vesselin T1 - Physical and numerical simulation of thermo-mechanical properties in the weld heat affected zone of an AlMgSi-alloy T2 - Materials Science Forum Y1 - 2012 SN - 0255-5476 VL - 706-709 SP - 1491 EP - 1496 ER - TY - CHAP A1 - Malikov, Viatcheslav A1 - Ossenbrink, Ralf A1 - Viehweger, Bernd A1 - Michailov, Vesselin T1 - FE-Simulation of deep drawing of structured sheet metals T2 - New technologies and achievements in metallurgy and materials engineering, XIII International Scientific conference, a collective monograph Y1 - 2012 SN - 978-83-87745-74-5 SP - 410 EP - 413 ER - TY - GEN A1 - Malikov, Viatcheslav A1 - Ossenbrink, Ralf A1 - Viehweger, Bernd A1 - Michailov, Vesselin T1 - Analytical and numerical calculation of the force and power requirements for air bending of structured sheet metals T2 - Key Engineering Materials KW - air bending, structured sheet metal, simulation Y1 - 2011 U6 - https://doi.org/10.4028/www.scientific.net/KEM.473.602 SN - 1013-9826 VL - Vol. 473 SP - 602 EP - 609 ER - TY - GEN A1 - Malikov, Viatcheslav A1 - Ossenbrink, Ralf A1 - Viehweger, Bernd A1 - Michailov, Vesselin T1 - Investigation of air bending of structured sheet metals by multistage FE simulation T2 - The International Journal of Advanced Manufacturing Technology Y1 - 2012 U6 - https://doi.org/10.1007/s00170-012-3927-4 SN - 1433-3015 VL - 63 IS - 5-8 SP - 449 EP - 455 ER - TY - BOOK A1 - Michailov, Vesselin A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf T1 - Sensibilitätsanalyse der thermomechanischen FE-Schweißsimulation KW - FE-Schweißsimulation, Sensibilitätsanalyse, FE-Netz, Wärmequellen, Werkstoffkennwerte Y1 - 2012 UR - http://www.shaker.de/de/content/catalogue/index.asp?lang=de&ID=8&ISBN=978-3-8440-1016-9 SN - 978-3-8440-1016-9 PB - Shaker CY - Aachen ER - TY - GEN A1 - Genchev, Gancho Vladimirov A1 - Dreibati, Ossama A1 - Ossenbrink, Ralf A1 - Doynov, Nikolay A1 - Michailov, Vesselin T1 - Physical and Numerical Simulation of the Heat-affected Zone of Multi-pass Welds T2 - Materials Science Forum N2 - The paper presents a numerical and experimental approach for the quantification of the thermo-mechanical properties in multi-pass weld’s heat affected zone (HAZ) of low alloy steel “S355J2+N”. First, the characteristic temperature cycles for multi-pass welds were identified by FE temperature field simulations of welding. Based on the identified temperature cycles, the microstructure in the HAZ has been physically simulated with the simulation and testing system Gleeble 3500 to investigate the influence of multi thermal exposure on the thermo-mechanical properties. Thus, the thermo-mechanical material properties including thermal strain and temperature dependent stress strain behaviour as function of peak temperatures and cooling rates have been determined. These material properties were used to calibrate a developed model for numerical prediction of the material properties of multi-pass weld HAZ. KW - welding simulation KW - multi-pass welds KW - thermo-mechanical properties KW - physical simulation, Gleeble Y1 - 2013 UR - www.scientific.net/MSF.762.544 SN - 0255-5476 IS - Vol. 762 SP - 544 EP - 550 ER - TY - CHAP A1 - Genchev, Gancho Vladimirov A1 - Ossenbrink, Ralf A1 - Doynov, Nikolay A1 - Michailov, Vesselin ED - Keßler, Olaf T1 - Gefügeeigenschaften in der Wärmeeinflusszone von Mehrlagenschweißungen aus S355J2+N T2 - Fortschritte in der Metallographie KW - Wärmeeinflusszone der Mehrlagenschweißung KW - experimentelle Werkstoffkennwerte Y1 - 2012 SN - 978-3-88355-392-4 SP - 167 EP - 172 PB - Inventum CY - Bonn ER - TY - CHAP A1 - Genchev, Gancho Vladimirov A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Simulation des Mehrlagenschweißens unter Berücksichtigung der Gefügeumwandlungen T2 - Conference proceedings, 2012 - ANSYS Conference & 30. CADFEM Users' Meeting, 24. - 26. Oktober 2012, Kassel N2 - Der Konferenzvortrag stellt das entwickelte M-STAAZ Modell vor. Mit dem M-STAAZ lässt sich in der FE-Simulation die Änderung der Werkstoffkennwerte bei mehrmaliger Temperaturbelastung wie in der WEZ von Mehrlagenschweißungen berücksichtigen. KW - Simulation des Mehrlagenschweißens KW - Gefügeumwandlungen KW - M-STAAZ Modell Y1 - 2012 UR - http://www.usersmeeting.com/rueckblick/acum-2012.html UR - http://www.cadfem.de/fileadmin/shop/um/ACUM2012-DVD-Inhaltsverzeichnis.pdf SP - Art. 2.2.9 PB - CADFEM GmbH CY - Grafing ER - TY - CHAP A1 - Genchev, Gancho Vladimirov A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Bewertung der relevanten Einflussfaktoren auf die Gefügeumwandlungen und thermomechanischen Eigenschaften bei komplexen Temperaturbelastungen T2 - ANSYS Conference & 29. CADFEM Users' Meeting 2011, conference proceedings, 19. - 21. October 2011, Stuttgart, ICS N2 - Der Vortrag stellt die Identifizierung und Bewertung der relevanten Einflussfaktoren auf die Gefügeumwandlungen und auf die thermomechanischen Werkstoffkennwerte bei komplexen Temperaturbelastungen vor. Dies erfolgt durch physikalische Simulation der Gefüge in der WEZ von Mehrlagenschweißungen und Aufnahme von Dilatometerkurven und Spannungs-Dehnungskurven. Es wurden einflussarme Kombination von Temperaturzyklen und weitere mit starkem Einfluss auf die Gefügeumwandlung identifiziert. Hinweise zu den erforderlichen Werkstoffkennwerten für die numerische Schweißsimulation wurden gegeben. KW - Gefügeumwandlungen bei mehrmaliger Temperatureinwirkung KW - thermomechanische Eigenschaften KW - Simulation des Mehrlagenschweißens Y1 - 2011 UR - http://www.usersmeeting.com/rueckblick/acum-2011.html UR - http://www.cadfem.de/fileadmin/shop/um/ACUM2011-DVD-Inhaltsverzeichnis.pdf SN - 3-937523-08-1 PB - CADFEM GmbH CY - Grafing ER - TY - THES A1 - Ossenbrink, Ralf T1 - Thermomechanische Schweißsimulation unter Berücksichtigung von Gefügeumwandlungen KW - Schweißsimulation KW - Eigenspannung KW - Laserstrahlschweißen KW - STAAZ-Modell KW - Stahl KW - Umwandlungsplastizität KW - thermomechanische Werkstoffkennwerte Y1 - 2009 SN - 978-3-8322-8131-1 PB - Shaker CY - Aachen ER - TY - CHAP A1 - Sasse, Ina A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Welding of structured sheet metals with high power fiber laser T2 - Międzynarodowa Sesja Studencka, 30. Mai 2012, Częstochowa/Polen KW - structured sheet metals; laser welding Y1 - 2012 SN - 978-83-87745-69-1 SP - 285 EP - 290 CY - Częstochowa ER - TY - CHAP A1 - Genchev, Gancho Vladimirov A1 - Ossenbrink, Ralf A1 - Doynov, Nikolay A1 - Michailov, Vesselin T1 - Material Properties of the HAZ of Multi-Pass Welded Joints from low alloyed Steel T2 - Junior Euromat 2012, Paperlist KW - material properties of the heat affected zone; multi-pass welds Y1 - 2012 UR - http://wiki.dgm.de/wwiki/wiki/Junior-Euromat%202012%20-%20Paperlist SP - A297 ER - TY - CHAP A1 - Ossenbrink, Ralf A1 - Brand, M. A1 - Michailov, Vesselin T1 - Numerische Simulation der Eigenspannungen und des Bauteilverzugs beim Schweißen mit Berücksichtigung des Umwandlungsverhaltens T2 - Große Schweißtechnische Tagung, Schweissen und Schneiden, 2003 KW - Laserstrahlschweißen; Eigenspannung; Verzug; numerische Simulation; thermomechanische Kennwerte Y1 - 2003 SN - 3-87155-683-1 SP - 279 EP - 283 PB - DVS-Verlag CY - Düsseldorf ER - TY - GEN A1 - Zhang, Wei A1 - Doynov, Nikolay A1 - Wolf, Matthias A1 - Dreibati, Ossama A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Investigation of the Thermal Shock Behavior of Ceramic Using a Combination of Experimental Testing and FE-Simulation Methods T2 - Advanced engineering materials N2 - Thermal shock behavior of ceramics plays a decisive role in their broad industrial applications. For enhanced understanding of damage and failure mechanism under thermal shock loading, in the present work, a combination of experimental testing and numerical simulation methods has been used. The thermal shock behavior of the alumina (99.7%) disk samples has been investigated by using a plasma test stand: the bottom of the ceramic disks were locally heated in the center by plasma beam; during the heat treatment the temperature distribution at the top of the sample was recorded with a thermographic system. To characterize the thermal shock resistance, a thermomechanical simulation was subsequently carried out. It calculates the temperature and stress distribution within the ceramic disks. The calculated critical thermal tension stresses are reported, which led to the failure of the ceramic disks under thermal shock loading. The effect of the sample thickness on the temperature and stress distribution is presented. Compared with the experimental results the simulated results show excellent agreement. As conclusion, it is possible to determine the thermal shock behavior of ceramic materials by the combination of experimental testing and numerical simulation. KW - Thermal Shock Behavior KW - Ceramic KW - FE-Simulation KW - Experimental Testing Y1 - 2013 UR - http://www.aem-journal.com U6 - https://doi.org/10.1002/adem.201200241 SN - 1527-2648 VL - 15 IS - 6 SP - 480 EP - 484 ER - TY - CHAP A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Vorhersage der Härteverteilung beim Schweißen mit Hilfe der numerischen Simulation T2 - Conference proceedings, 21st CAD-FEM Users' Meeting 2003, International Congress on FEM Technology, 12. - 14. November 2003, im Hotel Dorint Sanssouci Berlin, Potsdam KW - Numerische Simulation KW - Härteverteilung beim Schweißen Y1 - 2003 SN - 3-937523-00-6 N1 - Bericht 2.4.3 PB - CAD-FEM GmbH CY - Grafing bei München ER - TY - CHAP A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin A1 - Wohlfahrt, Helmut T1 - Numerische Simulation der Eigenspannungen und des Bauteilverzugs beim Schweißen unter Berücksichtigung der zeitlichen und örtlichen Änderung der Dehnrate T2 - Internationale FEM-Technologietage, 20th CAD-FEM Users' Meeting, 9-11 Oktober 2002, Friedrichshafen KW - Dehngeschwindigkeit KW - Dehngrenze KW - Eigenspannung KW - Laserstrahlschweißen KW - numerische Simulation KW - Verzug Y1 - 2002 N1 - Beitrag 2.8.4 PB - CAD-FEM GmbH CY - Grafing bei München ER - TY - GEN A1 - Kornienko, Elena A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Corrosion resistance of zinc-coated structured sheet metals T2 - Corrosion Science N2 - The purpose of this study is to characterise the corrosion behaviour of zinc-coated sheet metals after a structuring process using the salt spray test. The investigated structured material is manufactured by hydroforming and has a periodic hexagonal geometry. The corrosion behaviour has been evaluated by estimating the development of the corrosion area and penetration depth. The results of the investigation show that the corrosion area is larger on the smooth sheet than on the structured sheet. The difference between the structured and smooth sheets is negligible with increasing exposure time. Furthermore, the reasons for the different corrosion behaviours are discussed. KW - Corrosion KW - structur sheet metals Y1 - 2013 UR - http://www.sciencedirect.com/science/article/pii/S0010938X12006233 SN - 0010-938X VL - Vol. 69 SP - 270 EP - 280 ER - TY - CHAP A1 - Ossenbrink, Ralf A1 - Doynov, Nikolay A1 - Michailov, Vesselin T1 - Welding simulation of aluminium to steel joints by means of arc welding Processes T2 - 10th International Scientific and Technical Conference, Advanced metal materials and technologies (AMMT’2013), June 25–29, Saint Petersburg, 2013 N2 - The object of the present work is the introduction of a welding simulation approach for aluminium to steel welded joints which are realised by short-arc welding. The study is carried out with special emphasis on the simulation of temperature field by means of conduction solution, on the applicability of different metallurgical models as well as the aspects of the mechanical simulation of the residual welding stresses and distortions. As result an approved heat source model is suggested and the calibration parameters are presented. For the modelling of the microstructure and corresponding thermomechanical material properties in the heat affected zone different material models are validated. They are used to simulate the welding residual stresses and distortions. Furthermore, the welding simulation of a real component as well as a simulation study of different welding scenarios is presented. KW - Welding simulation; aluminium steel; welding Processes Y1 - 2013 SP - 523 EP - 528 PB - Izdat. Polytechn. Univ. CY - Saint Petersburg, Russia ER - TY - CHAP A1 - Ossenbrink, Ralf A1 - Genchev, Gancho Vladimirov A1 - Doynov, Nikolay ED - Michailov, Vesselin T1 - Simulation der Schweißeigenspannungen und des -verzuges unter Berücksichtigung der Gefügeumwandlungen mit dem STAAZ-Modell T2 - Internationales Symposium Schweißtechnik - Verfahren, Werkstoffe, Simulation, Cottbus, 6. November 2013 N2 - Die vorliegende Arbeit stellt das von Professor Michailov vorgeschlagene Spitzentemperatur-Austenitisierungs- Abkühlzeit-Modell für die thermomechanische Schweißsimulation unter Berücksichtigung der Gefügeumwandlungen vor. Das Modell erfasst die für die Gefügeausbildung maßgebenden Temperaturzyklen durch seine drei so genannten STAAZ-Parameter: Spitzentemperatur, Austenitisierungs- und Abkühlzeit. Die Korrelation dieser Temperaturzyklusparameter mit den thermomechanischen gefügeabhängigen Werkstoffeigenschaften erfolgt auf Grundlage einer empirischen Datenbasis. Mit der vorgenommenen Erweiterung zu Mehrmalig-(M-)STAAZ lässt sich das aus einem vorgelagerten Temperaturzyklus entstandene Zwischengefüge berücksichtigen. KW - Schweißsimulation; STAAZ-Modell ; thermomechanische Werkstoffkennwerte ; Mehrlagenschweißungen Y1 - 2013 SN - 978-3-8440-2319-0 SP - 149 EP - 167 PB - Shaker Verlag CY - Aachen ER - TY - GEN A1 - Sasse, Ina A1 - Schleuß, Leander A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Joining of structured sheet metals - Remote laser beam welding in comparison with resistance spot welding T2 - Welding and Cutting N2 - One main problem of thin-walled, large-area sheet components for lightweight construction solutions is the inadequate stiffness. One approach for a solution is provided by structured sheet metals which have an increased flexural stiffness due to three-dimensionally incorporated structures. The areas of application of the structured sheet metals (e.g. in subassemblies in automobile, rail vehicle and tank construction) necessitate adapted welding technologies. Since few systematic investigations have been conducted on structured sheet metals in the field of joining technology until now, there is a lack of knowledge about the further processing of these sheets by means of welding technology. The aims of the presented investigations are to make it possible to utilise these modern semi-finished products industrially using remote laser beam welding and to compare this with resistance spot welding. Both are important joining processes in the areas of applications interesting for structured sheet metals and thus constitute key technologies for industrial utilisation. Resistance spot welding has already been qualified for utilisation on structured sheet metals [1]. In addition, investigations were conducted into the remote laser beam welding of structured and flat sheets. These investigations encompass the possibilities of joining structured and flat joining members by means of remote laser beam welding as well as the assessment of the joint strength in tensile shear and peel tests. Thereafter, the results of the investigations are compared with the resistance spot welding of structured sheet metals and specific application recommendations are derived. KW - structured metals sheet KW - Remote laser beam welding KW - resistance spot welding Y1 - 2014 VL - 13 IS - 1 SP - 43 EP - 47 ER - TY - CHAP A1 - Sasse, Ina A1 - Schleuß, Leander A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Fügen strukturierter Bleche - Remote-Laserstrahlschweißen im Vergleich zum Widerstandspunktschweißen T2 - DVS Congress 2013, Große Schweißtechnische Tagung, DVS-Studentenkongress KW - strukturierte Bleche; Remote; Laserstrahlschweißen; Widerstandspunktschweißen Y1 - 2013 SN - 978-3-87155-614-2 SP - 98 EP - 103 PB - DVS-Verlag CY - Düsseldorf ER - TY - GEN A1 - Dreibati, Ossama A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Quantification of cold cracking parameters of high strength steels by physical simulation under welding conditions T2 - Quarterly journal of the Japan Welding Society N2 - Cold cracks in welds are the result of the formation of brittle microstructure as martensite in the presence of diffusible hydrogen as well as of tensile stresses. Cold cracks occur when the combination of cold crack influence parameters (CCIP) overcomes a critical limit. In this study, critical combinations of CCIP were identified with an enhanced test procedure under welding conditions. The test is based on the physical simulation technique of heat affected zone (HAZ) and it is carried out using the test and simulation center Gleeble 3500. Thereby, laboratory special specimens are charged with hydrogen from pure hydrogen atmosphere in the initial stage of the test. Rigidly restraint specimen section is subjected to different weld temperature cycles. Through the thermal exposure, the desired microstructure of HAZ is set in the test zone of the restraint specimen section. A plastic deformation takes place owing to the prevented expansion during heating and contraction of the specimen during cooling. Consequently, compressive or tensile reactions stresses arise in the deformed zone. Cracked specimen represents a critical combination of the CCIP. The quantitative cold crack criterion separates the cold crack susceptible combinations from those non susceptible. KW - Cold Cracking KW - Physical Simulation KW - High Strength Steel Y1 - 2013 U6 - https://doi.org/10.2207/qjjws.31.148s SN - 0288-4771 VL - 31 IS - 4 SP - 148 EP - 152 ER - TY - GEN A1 - Michailov, Vesselin A1 - Dreibati, Ossama A1 - Ossenbrink, Ralf A1 - Schweizer, Frank T1 - Rechnergestützte Vorhersage der Kaltrissneigung laserstrahlgeschweißter Bauteile aus hochfesten Stählen - Teil 1 T2 - Schweißen und Schneiden : Fachzeitschrift für Schweißen und verwandte Verfahren KW - Kaltriss KW - hochfeste Stähle KW - laserstrahlgeschweißte Bauteile Y1 - 2013 SN - 0036-7184 VL - 65 IS - 11 SP - 776 EP - 781 ER - TY - CHAP A1 - Schleuß, Leander A1 - Springer, Katrin A1 - Zoeke, Jörg A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Qualifizierung von wärmearmen MSG-Schweißverfahren für Leichtbaukonstruktionen mit strukturierten Halbzeugen T2 - Internationaler Fachkongress der Schweiß- und Verbindungstechnik Join-Ex 2012 Wien, 10. + 11. Oktober 2012, Congress Center der Messe Wien KW - wärmearm KW - Schweißen KW - strukturiert KW - Steifigkeitserhöhung KW - Hochgeschwindigkeitsaufnahme KW - Temperaturzyklen Y1 - 2012 SP - 75 EP - 83 PB - Schweißtechnische Zentralanstalt e.V. CY - Wien ER - TY - GEN A1 - Kazak, Fedor A1 - Schleuß, Leander A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin A1 - Weiß, Sabine T1 - Particularities of testing structured sheet metals in 3-point bending tests T2 - Materials Testing N2 - Thin sheet metals from deep drawing steel DC04 are very often used in the production of car body and case parts. Quality improvement of sheet metal components by new constructive solutions (structuring) as well as adapted joining technology is going on. Structured sheet metals differ from each other by their high bending stiffness. At the same time, they show certain anisotropy due to the structure. Therefore a typical testing method of structured semi-finished parts (single sheet metals, sandwiches)is the bending test. The literature review revealed that in many studies no special demands on tests of structured materials were made. This concerns particularly the structure arrangement, structure direction and structure location of the specimen relative to the mandrel position during bending tests, i. e., the direction of the fixed load relative to the structure. The aim of this study was to determine the influence of the test specification on flexural behavior. In the present paper, honeycomb-structured sheet metals were examined using 3-point bending tests. Bending stiffness and lightweight potential were calculated with respect to the location of load application and compared for different structure arrangements,directions and locations. The influence of the anisotropy on flexural behavior of the honeycomb-patterned sheet metals was moderate. Y1 - 2016 U6 - https://doi.org/10.3139/120.110883 SN - 0025-5300 SN - 2195-8572 VL - 58 IS - 6 SP - 495 EP - 500 ER - TY - GEN A1 - Zhang, Wei A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Physical and FE-Simulation of Thermal Shock Behaviour of Refractory Ceramics T2 - refractories WORLDFORUM Y1 - 2016 SN - 1868-2405 VL - 8 IS - 2 SP - 110 EP - 117 ER - TY - CHAP A1 - Zhang, Wei A1 - Priefer, Marian A1 - Olenina, Mariia A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Additive manufacturing by laser beam build-up welding T2 - 6th International Conference on Additive Technologies - iCAT 2016, Nürnberg, Germany, 29. - 30. November 2016 Y1 - 2016 SN - 978-961-285-537-6 SP - 324 EP - 327 ER - TY - CHAP A1 - Zhang, Wei A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin A1 - Scheithauer, Uwe A1 - Michaelis, Alexander T1 - Investigation of thermal shock behaviour of refractory ceramics based on the calcium-aluminate T2 - 14th Biennial Worldwide Congress Unified International Technical Conference on Refractories (UNITECR) 2015, Vienna, Austria, September 15-18, 2015 Y1 - 2015 SN - 978-3-9815813-1-7 CY - Hannover ER - TY - GEN A1 - Atanga, Valetine Kubong A1 - Zhang, Wei A1 - Dreibati, Ossama A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin A1 - Scheffler, Michael T1 - Alumina-mullite Materials for Refractory Applications: Microstructure, Physical and Finite Element Simulation of Thermal Shock Behaviour T2 - refractories WORLDFORUM Y1 - 2012 SN - 1868-2405 VL - 4 IS - 1 SP - 159 EP - 164 ER - TY - GEN A1 - Genchev, Gancho Vladimirov A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Modelling the Local Microstructure Properties due to Multi-Pass Welding T2 - Materials Science Forum Y1 - 2017 U6 - https://doi.org/10.4028/www.scientific.net/MSF.879.595 SN - 0255-5476 SN - 1662-9752 N1 - International Conference on Processing & Manufacturing of Advanced Materials Processing, Fabrication, Properties, Applications, May 29 - June 3, 2016 Graz, Austria VL - Vol. 879 SP - 595 EP - 600 ER - TY - CHAP A1 - Seidlitz, Holger A1 - Fritzsche, Sebastian A1 - Schleuß, Leander A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Neuartige Fügetechnologie zum Herstellen von hochbelastbaren Multi-Material-Bauweisen aus textilverstärkten Kunststoffen und Metallen bei einseitiger Zugänglichkeit der Fügestelle T2 - DVS Congress 2016, Große Schweißtechnische Tagung, Vorträge der Veranstaltungen in Leipzig am 19. und 20. September 2016 Y1 - 2016 SN - 978-3-945023-74-7 SP - 424 EP - 428 PB - DVS-Verlag CY - Düsseldorf ER - TY - CHAP A1 - Genchev, Gancho Vladimirov A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Schweißtechnische Simulation der lokalen Eigenschaften in der Wärmeeinflusszone von Mehrlagenschweißungen T2 - ANSYS Conference & 33rd CADFEM Users' Meeting, 24. - 26. Juni, Bremen, conference proceedings Y1 - 2015 PB - CADFEM GmbH CY - Grafing ER - TY - GEN A1 - Genchev, Gancho Vladimirov A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Bokuchava, Gizo A1 - Petrov, Peter A1 - Michailov, Vesselin T1 - Numerical and Experimental Study of Residual Stress Distribution in Laser Beam Welded Joint Y1 - 2016 UR - https://www.tugraz.at/fileadmin/user_upload/Events/Seggau/Dokumente/Dokumente_THERMEC/Program_Book_April_2016.pdf N1 - THERMEC 2016, 9th International Conference on Processing & Manufacturing of Advanced Materials, May 29-June 03, 2016, Graz, Austria SP - S. 20 ER - TY - GEN A1 - Schleuß, Leander A1 - Richter, Thomas A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Plasma Cutting of Structured Sheet Metals in Comparison with Laser Beam Cutting T2 - Journal of Materials Science and Engineering Y1 - 2015 U6 - https://doi.org/10.17265/2161-6221/2015.3-4.004 SN - 2161-6221 VL - 5 IS - 3-4 SP - 135 EP - 144 ER - TY - GEN A1 - Nikitin, Alexander A1 - Schleuß, Leander A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Corrosion Behavior of Brazed Zinc-Coated Structured Sheet Metal T2 - International Journal of Corrosion Y1 - 2017 U6 - https://doi.org/10.1155/2017/4768505 SN - 1687-9333 SN - 1687-9325 VL - 2017 SP - 4768505 ER - TY - CHAP A1 - Zhang, Wei A1 - Priefer, Marian A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Neue Möglichkeiten für die Additive Fertigung durch Laser-Pulver-Auftragschweißen T2 - DVS Congress 2017, Große Schweißtechnische Tagung, DVS Studentenkongress, Vorträge der Veranstaltungen in Düsseldorf vom 26. bis 29. September 2017 KW - Laser Additive Fertigung Y1 - 2017 SN - 978-3-96144-008-5 SP - 278 EP - 282 PB - DVS Media CY - Düsseldorf ER - TY - GEN A1 - Genchev, Gancho Vladimirov A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin A1 - Bokuchava, Gizo A1 - Petrov, Peter T1 - Residual stresses formation in multi-pass weldment: A numerical and experimental study T2 - Journal of Constructional Steel Research N2 - In this study, the residual stresses distribution induced by multi-pass arc welding of the steel S355J2+N are investigated experimentally and numerically. An extended approach is used for the simulations, which considers the change of the local microstructure properties due to multiple reheating. Experimental material data obtained from physical welding simulations with Gleeble® are used for the model calibration. The experimental stress study is performed using a neutron diffraction method on a fourier stress diffractometer. Numerical analysis of the welding stresses formation in the weldment is performed and compared to the experimental study. The results explain the influence of the welding thermal history on the resulting local thermo-mechanical properties in the heat-affected zone and, thus, on the residual stress distribution. The consideration of the local microstructure properties in the welding simulation leads to a significant increase in accuracy of the numerical results. The major influence factor on the residual stress formation is the change in the interpass microstructure yield strength. When a root pass with short cooling times is subjected to re-austenitisation in the fine-grained zone, the yield strength increases in this area and affects consequently the residual stress distribution. The influence of the reheating is detectable in the depth of the weldment, but it is less significant for the residual stress formation near the surface of the welded joint. KW - Multi-pass weldment KW - Steel S355 KW - Thermo-mechanical properties KW - Stress distribution KW - Welding simulation KW - Neutron diffraction Y1 - 2017 UR - http://www.sciencedirect.com/science/article/pii/S0143974X17303358 U6 - https://doi.org/10.1016/j.jcsr.2017.08.017 SN - 0143-974X VL - 138 SP - 633 EP - 641 ER - TY - GEN A1 - Evdokimov, Anton A1 - Springer, Katrin A1 - Doynov, Nikolay A1 - Ossenbrink, Ralf A1 - Michailov, Vesselin T1 - Heat source model for laser beam welding of steel-aluminum lap joints T2 - International Journal of Advanced Manufacturing Technology N2 - In this study, a three-dimensional thermal conduction model based on the finite element analysis was established to predict a heat distribution during laser welding in overlap configuration of austenitic stainless steel 1.4301 and hardenable aluminum alloy 6016. A hybrid model based on two expanded curve-rotated volumetric heat sources is suggested to capture the complex weld geometry. Since thermal flow in the overlap area is a crucial part of the model, an analytic calculation of a thermal contact conductance between the plates and its subsequent implementation in the FE model through a superposition of two contact surfaces are described in details in this paper. Full thermal cycles, weld shapes, and thus mixing grades were successfully predicted by means of the developed model for different parameter combinations. KW - Laser welding Dissimilar joint Heat source model Finite element analysis Thermal simulation Weld shape KW - Dissimilar joint KW - Heat source model KW - Finite element analysis KW - Thermal simulation KW - Weld shape Y1 - 2017 UR - https://link.springer.com/article/10.1007/s00170-017-0569-6 U6 - https://doi.org/10.1007/s00170-017-0569-6 SN - 0268-3768 SN - 1433-3015 VL - 93 IS - 1-4 SP - 709 EP - 716 ER - TY - GEN A1 - Evdokimov, Anton A1 - Obrosov, Aleksei A1 - Ossenbrink, Ralf A1 - Weiß, Sabine A1 - Michailov, Vesselin T1 - Mechanical properties of dissimilar steel-aluminum weld T2 - Materials Science and Engineering: A N2 - Knowledge of the properties of dissimilar welds is of great significance for the development of multi-material lightweight structures. In this study, stainless steel (1.4301) and aluminum alloy (6082-T6) sheets were welded in overlap configuration in keyhole mode. The resulting weld metals were investigated with respect to their mechanical properties. Several samples were cut out of different locations along the welds and their cross-sections were subjected to indentation testing and energy dispersive X-ray (EDS) analysis. Young's modulus E, yield stress σy, and strain hardening exponent n, were determined by means of reverse analysis of the indentation load (P) – depth (h) curves, allowing construction of true stress – true strain relations. An essential increase in yield stress in comparison to the one of the base alloys was observed inside the weld metal. In contrary, Young's modulus and strain hardening exponent of the welds were almost identical to corresponding values of the base steel metal. Due to the sensitivity of yield stress to the aluminum content, slight variations of the welding parameters lead to significant changes in elastic-plastic behavior of the weld metal. KW - Mechanical properties KW - Indentation KW - Reverse analysis KW - EDS measurements KW - Dissimilar steel aluminum welding KW - FEM Y1 - 2018 UR - https://www.sciencedirect.com/science/article/pii/S0921509318303563 U6 - https://doi.org/https://doi.org/10.1016/j.msea.2018.03.019 SN - 0921-5093 VL - Volume 722 SP - 242 EP - 254 ER - TY - PAT A1 - Michailov, Vesselin A1 - Ossenbrink, Ralf A1 - Schleuß, Leander A1 - Springer, Katrin A1 - Zoeke, Jörg T1 - Strukturierte Tailored Blanks T1 - Structured tailored blank useful as a semi-finished product or a finished product, which is used as a component, preferably wall element, floor element, ceiling element and/or element of chassis of vehicle, comprises at least two sheets N2 - Die Erfindung betrifft ein strukturiertes Tailored Blank, umfassend mindestens zwei Fügepartner, wobei mindestens ein Fügepartner ein strukturierter Fügepartner ist und wobei der strukturierte Fügepartner regelmäßig angeordnete Versteifungselemente umfasst und wobei der strukturierte Fügepartner an mindestens einen weiteren Fügepartner gefügt ist. N2 - Structured tailored blank comprises at least two sheets. At least one sheet is at least one structured sheet. The structured sheet comprises regularly arranged stiffening elements of honeycomb shapes without planar sections. The stiffening elements are separated by bars. The structured sheet is joined to at least one additional sheet, and both the sheets are not similar. An independent claim is also included for producing the structured tailored blank, comprising the providing first structured sheet, providing at least one additional sheet, which is not similar to the first sheet, and joining the first sheet with at least one additional sheet. Y1 - 2014 UR - https://depatisnet.dpma.de/DepatisNet/depatisnet?action=pdf&docid=DE102013101171A1 ER - TY - GEN A1 - Michailov, Vesselin A1 - Fritzsche, Sebastian A1 - Hantelmann, Cord A1 - Ossenbrink, Ralf T1 - Aluminium foam sandwiches for lightweight structures T2 - Metal Science and Heat Treatment N2 - The properties of sandwiches with aluminum foam and the special features of their use in lightweight welded structures are determined. The weldability of such sandwiches in foamed and non-foamed conditions is analyzed under friction stir welding, laser beam welding and short arc welding in protective gas. The process and mechanical properties of the welds are studied. The results are generalized in a catalog that may be useful for materials scientists and designers. KW - aluminum KW - aluminum foam KW - welded structures KW - composite materials KW - structure KW - mechanical properties Y1 - 2018 U6 - https://doi.org/10.1007/s11041-018-0238-x SN - 1573-8973 VL - 60 IS - 1-2 SP - 44 EP - 49 ER -