Publications

Publications

Journal articles

  • Ståhlberg K, Goerlandt F, Ehlers S, Kujala P. Impact scenario models for probabilistic risk-based design for ship–ship collision. Marine Structures 33 (2013) 238–264.
  • von Bock und Polach R, Ehlers S. Model scale ice - Part B: Numerical model. Cold Regions Science and Technology 94 (2013) 53–60.
  • von Bock und Polach R, Ehlers S, Kujala P. Model-Scale Ice - Part A: Experiments.  Cold Regions Science and Technology. doi: 10.1016/j.coldregions.2013.07.001
  • Ehlers S. Kujala P. Optimization-based material parameter identification for the numerical simulation of sea ice in four-point bending. Journal of Engineering for the Maritime Environment 2013.
  • Sormunen OVE, Ehlers S, Kujala P. Collision consequence estimation model for chemical tankers. Journal of Engineering for the Maritime Environment 2013, 98.
  • Jelovica J, Romanoff J, Ehlers S, Aromaa, J. Ultimate strength of corroded web-core sandwich beams. Marine Structures 2013; 31,1-14.
  • Dai L, Ehlers S, Rausand M, Bouwer Utne I. Risk of collision between service vessels and offshore wind turbines. Reliability Engineering and System Safety; 2013;109; 18–31.
  • Erikstad SO, Ehlers S. Decision support framework for exploiting northern sea route transport opportunities. Ship Technology Research, 2012.
  • Montewka J, Ehlers S, Tabri K. Modelling risk of a collision between a LNG tanker and a harbour tug. Marine Systems & Ocean Technology, 2012;7(1),5-15.
  • Jelovica J, Romanoff J, Ehlers S, Varsta P. Influence of weld stiffness on buckling strength of laser-welded web-core sandwich plates. Journal of Constructional Steel Research, 2012; 77; 12-18.
  • Ehlers S. Østby E. Increased crashworthiness due to arctic conditions ? The influence of sub-zero temperature. Marine Structures, 2012. doi:10.1016/j.marstruc.2012.05.004
  • Ehlers S. Tabri K. A combined numerical and semi-analytical collision damage assessment procedure. Marine Structures, 2012. doi:10.1016/j.marstruc.2012.05.005
  • Ehlers S. High strength steel in crashworthy ship structures. Journal of Ship production and Design, 2012; 28 (1); 1-9.
  • von Bock und Polach RUF, Ehlers S. Heave and pitch motions of a ship inmodel ice: an experimental study on ship resistance and ice breaking pattern. Cold Regions Science and Technology, 2011; 68; 49-59.
  • Ehlers, S. A review of collision and grounding damage assessment method. Marine Systems & Ocean Technology, 2011; 6(1); 5-15.
  • Ehlers S, Remes H, Klanac A, Naar H. A multi-objective optimisation-based structural design procedure for the concept stage - a chemical product tanker case study. Ship Technology Research, Schiffstechnik, 2010; 57(3): 182-197.
  • Ehlers S. Optimisation for Crashworthiness. Brodogradnja-Shipbuilding 2010; 61(4): 341-346.
  • Rigo P, Žanić V, Ehlers S, Andrić J. Design of Innovative Ship Concepts using an Integrated Decision Support System for Ship Production and Operation. Brodogradnja-Shipbuilding 2010; 61(4): 367-381.
  • Ehlers S, Tabri K, Romanoff J, Varsta P. Numerical and Experimental Investigation on the Collision Resistance of the X-core Structure. Journal of Ships and Offshore Structures, Special Issue on Collision and Grounding, 2010; xx(xx), 1–9.
  • Ehlers S. A procedure to assess the damage of a grounded ship: a full-scale validation case study. Ship Technology Research, 2010; 57(1); 50-64.
  • Ehlers S. The influence of the material relation on the accuracy of collision simulations. Marine Structures, 2010; 23; 462-474.
  • Kõrgesaar M, Ehlers S. An Assessment Procedure of the Crashworthiness of an LNG Tanker Side Structure. Ship Technology Research, Schiffstechnik, 2010; 57(1): 50-64.
  • Ehlers S. A procedure to optimize ship side structures for crashworthiness. Journal of Engineering for the Maritime Environment 2009; 224: 1-12.
  • Ehlers S. Strain and stress relation until fracture for finite element simulations of a thin circular plate. Thin-Walled Structures 2009; 48(1); 1-8.
  • Klanac A, Ehlers S, Jelovica J. Optimization of crashworthy marine structures, Marine Structures 2009; 22(4); 670-690.
  • Ehlers S, Varsta P. Strain and stress relation for non-linear finite element simulations. Thin-Walled Structures 2009; 47; 1203-1217.
  • Ehlers S, Broekhuijsen J, Alsos HS, Biehl F, Tabri K. Simulating the collision response of ship side structures: A failure criteria benchmark study. Int Ship Progress 2008; 55: 127-144.

 

Guest editor

  • Special Issue on Arctic Sea Transportation for Ocean Engineering - upcoming for 2015.
  • Wang G, Ehlers S. Special Issue on Collision and Grounding of Ships. Journal of Ships and Offshore structures.

 

ISSC reports

  • 2009-2012: Committee member: V.1: Damage Assessment Following Accidents. 2012. Jerzy Czujko (Chairman), Natacha Buannic, Sören Ehlers, Chen-Far Hung, Frank Klæbo, Spiro J. Pahos, Mark Riley, Wenyong Tang, Alex Vredeveldt, John Wægter.
  • 2012-2015: Committee chairman: V.6: Arctic Technology. Alexei Bereznitski, Fai Cheng, Ian Jordaan, Walter Kuehnlein, Pentti Kujala, Yu Luo, Yeong Tae Oh, Kai Riska, Jaideep Sirkar, Koji Terai, Janne Valkonen.

 

Invited speaker

  • Consequence assessment of accidental ice impact for ships. Tekna kursdagene, Trondheim, 2013.
  • Arctic Sea transportation and vessel Design. The 5th Seoul International Maritime and Shipbuilding Conference, SIMS, Busan, Korea, November 2012.
  • Design and construction of vessels for the High North. Russian Norwegian Working Group on Shipbuilding. Ålesund, Norway, October 2012.
  • Ports for Container Ships of Future Generations, Workshop, TUHH, 2011. Grounding and Collision of Ships - a state of the art review, pp. 123-136.

 

Conference proceedings

  • 5th International Conference on Collision and Grounding of Ships edited by Ehlers S, Romanoff J. 2010. 263 pages.
  • 6th International Conference on Collision and Grounding of Ships edited by Amdahl J, Ehlers S, Leira BJ. 2013.

 

Summary articles

  • Ehlers S, Tabri K, Varsta P. Collision strength of Ship Structures – A state of the art review. To appear in: CENTEC (Lisbon) 15th anniversary book 2009/10.

 

Conference articles

  • Tomac T, Klanac A, Katalinic M, Ehlers S, von Bock und Polach R, Suominen M, Montewka J. Numerical simulations of ship resistance in model ice. In Developments in Maritime Transportation and Exploitation of Sea Resources - IMAM 2013; 847-851.
  • Montewka J, Goerlandt F, Ehlers S, Hinz T, Kujala P. A risk framework for maritime transportation systems. In Proceedings of the 13th Int. Ship Stability Workshop, Brest 23-26.09.2013.
  • Erceg S, Ehlers S, Ellingsen IH, Slagstad D, von Bock und Polach R, Erikstad SO. Ship performance assessment for arctic transport routes. OMAE 2013.
  • Kujala P, Ehlers S. Limit state identification for ice-strengthened hull structures using measured long-term loads. POAC 2013.
  • Ehlers S., Kujala P. Cost optimization for ice-loaded structures. Analysis and Design of Marine Structures; 2013-03-25 - 2013-03-27
  • Polic D, Ehlers S, Æsoy V, Pedersen V. Propulsion machinery operating in ice – a modelling and simulation approach. ECMS 2013.
  • Borch O.J., Westvik  M. H., Ehlers S., Berg T. E. Sustainable arctic field and maritime operation. Arctic Technology Conference, OTC Paper Number 23752, Houston, 2012.
  • Ehlers S. von Bock und Polach. Arctic ship design challenges – ice loading and the influence of sub-zero temperature. Annual meeting of the society of german naval architects, November 2012.
  • Montewkaa J, Ehlers S, Goerland F, Hinz T, Kujalaa P. A model for risk analysis of RoPax ships - the Gulf of Finland case. In the proceedings of ESREL 2012 conference, 23rd-27th of June 2012, Helsinki.
  • Ehlers, S. A particle swarm optimization-based procedure to obtain a crashworthy ice-classed LNG tanker. I: Collision and Grounding of Ships and Offshore Structures. CRC Press 2013 ISBN 978-1-138-00059-9. p. 233-240
  • Ehlers S., Benson S., Misirlis K. Ultimate strength of an intact and damaged LNG vessel subjected to sub- zero temperature. I: Collision and Grounding of Ships and Offshore Structures. CRC Press 2013 ISBN 978-1-138-00059-9. p. 289-296
  • Omre A, Sørstrand S, Ehlers S, von Bock und Polach R. A sustainable transport system for the arctic sea. IMDC2012.
  • Ståhlberg K, Ehlers S, Kujala P. Design scenario modeling for assessing passenger vessel crashworthiness. IMDC2012
  • Storheim M, Kim E, Amdahl J, Ehlers S. Iceberg shape sensitivity in ship impact assessment in view of existing material models. OMAE2012
  • von Bock und Polach R, Janardanan V, Ehlers S. Ice model tests in context of the investment value of an offshore vessel. OMAE2012
  • Tabri K, Ehlers S, Korgesaar M, Ståhlberg K, Heinvee M. Collision consequence assessment of ROPAX vessels operating in the Baltic Sea. OMAE2012
  • Erikstad SO, Ehlers S. A Decision Support Framework for Exploiting Northern Sea Route Transport Opportunities. Compit 2012.
  • Jelovica J, Romanoff J, Ehlers S, Aromaa A. Experimental investigation on ultimate strength of corroded web-core sandwich panel stripes, International conference on composite materials (ICCM 18), 21-26 August 2011, Jeju, Korea.
  • Montewka J, Goerlandt F, Ehlers S, Kujala P, Erceg S, Polic D, Klanac A, Hinz T, Tabri K. A model for consequence evaluation of ship-ship collision based on Bayesian Belief Network. In Rizutto&Guedes Soares (eds), Sustainable Maritime Transportation and Exploation of Sea Resources, Taylor&Francis, London, 2011; 721-728.
  • Ehlers S. A Particle Swarm Algorithm-Based Optimisation for High- Strength Steel Structures. COMPIT 2011.
  • Ehlers S, Klanac A, Schröder M. An investigation of a Suezmax tanker grounding accident. Hamburg, Deutschland. Marstruct 2011.
  • D. Polić, D. Frank, A. Klanac, S. Ehlers. Finite element-based shape optimization of an asymmetric steel sandwich panel joint. Marstruct 2011.
  • Montewka J, Ehlers S, Tabri K. Elements of risk analysis for LNG tanker maneuvering with tug assistance in a harbor. 11th Symposium on Practical Design of Ships and Other Floating Structures, Rio de Janeiro, Brasil 2010.
  • Frank D, Klanac A, Kniep M, Polić, Ehlers S. Optimization system for design of laser-welded steel-sandwich structures. 11th Symposium on Practical Design of Ships and Other Floating Structures, Rio de Janeiro, Brasil 2010.
  • Ehlers S, Tabri K, Romanoff J, Varsta P. Numerical and Experimental Investigation on the Collision Resistance of the X-core Structure. 5th Intl. Conference on Collision and Grounding of Ships. 2010; 18-24.
  • Ehlers, S. A material relation for ship collision simulations. 5th Intl. Conference on Collision and Grounding of Ships. 2010; 113-117.
  • Klanac A, Duletić T, Erceg S, Ehlers S, Frank D. Environmental risk of collisions in the enclosed European waters: Gulf of Finland, Northern Adriatic and the implications for tanker design. 5th Intl. Conference on Collision and Grounding of Ships. 2010; 55-65.
  • Varsta P, Ehlers S, Klanac A, Tabri K. Collision and Grounding of Ship Structures. In Advanced Ship Design for Pollution Prevention. 2010; 191-204.
  • Ehlers S. Optimization for Crashworthiness. 10th Finnisch Mechanics Days. Jyväskylä, Finland. 2009; 85-93.
  • Ehlers S, Klanac A, Remes H, Kapuścik K, Naar H, Andric J, Zanic V, Grgic M, Pircalabu, E, Bair F. The IMPROVEd chemical tanker. IMPROVE-Conference, Dubrovnik, Kroatien. 2009; 136-145.
  • Ehlers S, Kapuścik K, Khalid H, Turan O. The basic design, performance and stability of the IMPROVEd chemical tanker. IMPROVE-Conference, Dubrovnik, Kroatien. 2009; 131-135.
  • Remes H, Klanac A, Varsta P, Ehlers S. ConStruct – Platform for Conceptual Structural Design. IMPROVE-Conference, Dubrovnik, Kroatien. 2009; 86-91.
  • Ehlers S, Klanac A, Kõrgesaar M. A design procedure for structures against impact loading. Vorgetragen in der Jahreshauptversammlung der Schiffbautechnischen Gesellschaft in Hamburg 2008, die schriftliche Fassung erschien im Jahrbuch 2008.
  • Ehlers S, Klanac A, Tabri K. Increased safety of a tanker and a RO-PAX vessel by implementing a novel sandwich structure. 4th Intl. Conference on Collision and Grounding of Ships. Germany, 2007; 109-115.
  • Tabri K, Alsos H, Broekhuijsen J, Ehlers S. A benchmark study on ductile failure criteria for shell elements in multiaxial stress state. Advancements in Marine Structures. 2007; 401-409.
  • Ehlers S, Tabri K, Schillo N, Ranta J. Implementation of a novel ship side structure into a tanker and a ropax vessel for increased crashworthiness. 6th European LS-DYNA Users' Conference, Gothenburg, Sweden. 2007; 4.111-4.120.
  • Klanac A, Tabri K, Ehlers S, Nekic A. Multi-Attribute Design of Crashworthy Structures in the Bi-Stakeholder Environment, International Marine Design Conference – IMDC, Ann Arbor, 2006.
  • Ehlers S. Design of steel sandwich panel joints with respect to fatigue life. Sommertagung der Schiffbautechnischen Gesellschaft in Stettin 2004. Erschienen im Jahrbuch 2006, Band 98, ISBN 3-540-27423-5.
  • Klanac A, Ehlers S, Tabri K, Rudan S, Broekhuijsen J. Qualitative design assessment of crashworthy structures. Proc Int Maritime Association of Mediterranean, Portugal. 2005; 461-469.
  • Klanac A, Ehlers S, Tabri K. Analysis of crashworthy structures. Maritime Research News 2005, Vol. 20.
  • Ehlers S. Design of steel sandwich panel joints. Ship structural design seminar, Espoo, Finland 2005.
  • Kujala P, Romanoff J, Tabri K, Ehlers S. All Steel Sandwich Panels – Design Challenges for Practical Applications on Ships. 9th Symposium on Practical Design of Ships and Other Floating Structures, Lübeck-Travemünde, Deutschland 2004.

 

Reports

  • Jelovica J, Romanoff J, Ehlers S, Remes H. Ultimate strength tests of corroded web-core and corrugated-core sandwich beams. Aalto University, Dept. of Applied Mechanics. Research Report 2011. http://lib.tkk.fi/SCIENCE_TECHNOLOGY/2011/isbn9789526044347.pdf
  • Ehlers S, Enquist B. Uni axial tensile necking of steel dog-bone specimens. Helsinki University of Technology, Ship Laboratory, M-303, 2007.
  • Ehlers S. A thin circular plate under hemi-spherical punch; An experimental study of a plate subjected to a displacement controlled punch. Helsinki University of Technology, Department of Applied Mechanics, TKK-AM-7, 2009.

Contact

Contact

Sören Ehlers
 
Professor, D.Sc. (Tech.)
 
Department of Marine Technology
 
Phone: +4773595596
Mobile: +4791897748
Email: soren.ehlers@ntnu.no
Marinteknisk senter, room E2.232
Otto Nielsens veg 10, 7491 Trondheim