PSI - Issue 2_A

Ann-Christin Hesse et al. / Procedia Structural Integrity 2 (2016) 3523–3530 Author name / Structural Integrity Procedia 00 (2016) 000–000

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 The different circumstances in Charpy V-notch specimen and fracture mechanics specimen (blunt notch vs. fatigue cracked notch, lower constraint due to the size in Charpy specimen and different loading rates) lead to different behaviours concerning crack path deviation. While crack path deviation was observed in Charpy specimen (e.g. even below -120 °C for the S355NL specimen) fracture testing at comparatively higher temperatures (-40 °C) show failure within the weld seam. Therefore failure behaviour during Charpy testing may not be transferred to failure behaviour of structural elements.  The sigmoidal compensation curves which are commonly used to describe the Charpy transition curve should not be used for beam welds due to the change in fracture behaviour. It is suggested to use separate compensation curves for every failure pattern investigated (failure within the weld seam, CPD into fusion line or CPD into base metal).  The modified Sanz-correlation could be verified for the investigated steels although the yield strength of the S960QL base material exceeded the material range that was investigated in comparable studies. As both data points shown in the left part of Figure 5 lie between the 1σ- and the 2σ-deviation line above the curve further investigations are recommended. If this trend is confirmed, a more accurate correlation should be determined for beam welded steels. 6. Acknowledgements We would like to thank the German Federation of Industrial Research Associations (AiF) for its financial support of the research project IGF-No. 18087N. This project was carried out under the auspices of AiF and financed within the budget of the Federal Ministry of Economics and Technology (BMWi) through the programme to promote joint industrial research and development (IGF). 7. References ASTM E1820-15a, 2015. Standard Test Method for Measurement of Fracture Toughness, ASTM International, West Conshohocken, PA. ASTM E1921-15ae1, 2015. Standard Test Method for Determination of Reference Temperature, To, for Ferritic Steels in the Transition Range, ASTM International, West Conshohocken, PA Bezensek, B., Hancock, J. W., 2007. The toughness of laser welded joints in the ductile–brittle transition. Engineering fracture mechanics, 74(15), 2395-2419. Cam, G., Erim, S., Yeni, C., Kocak, M., 1999. Determination of mechanical and fracture properties of laser beam welded steel joints. Welding Journal, 78, 193-s. DIN EN 1993-1-10, (2010).Eurocode 3: Design of steel structures - Part 1-10: Material toughness and through-thickness properties; German version EN 1993-1-10:2005 + AC:2009. Elmer, J. W., Giedt, W. H., Eagar, T. W., 1990. The transition from shallow to deep penetration during electron beam welding. Welding Journal, 69(5), 167s-175s. Feldmann, M., 2010. Choice of steel material to avoid brittle fracture for hollow section structures addition to EN 1993-1-10. Editors: Géradin, M., Pinto, VA, Amorim-Varum, H., JRC Publication. Goldak, J. A., Nguyen, D. S., 1977. A fundamental difficulty in Charpy V-notch testing narrow zones in welds. Weld. J.(Miami, FL, US), 56(4), 119-125. ISO 148-1, 2009. Metallic materials - Charpy pendulum impact test - Part 1: Test method (ISO 148-1:2009) ISO 15653:2010, 2010. Metallic materials - Method of test for the determination of quasistatic fracture toughness of welds. Lancaster, J. F., 1984. The physics of welding. Physics in technology, 15(2), 73. Nagel, M., Langenberg, P., Lüder, F., Bleck, W., Dilthey, U., 2002. Discussion of testing procedures for the determination of the toughness properties of laser welded joints. European Structural Integrity Society, 30, 253-261. Stranghöner, N., Sedlacek, G., Stözel, G., Dahl, W., Langenberg, P., 1997. The New Eurocode 3-Part 2-Annex C: Approach For the Choice of Steel Material to Avoid Brittle Fracture. In The Seventh International Offshore and Polar Engineering Conference. International Society of Offshore and Polar Engineers. Sumpter, J. D. G., 1996. Fracture toughness of laser welds in ship steel. Advanced Performance Materials, 3(3-4), 393-405. Anderson, T. L., 2005. Fracture mechanics: fundamentals and applications. CRC press. Andrich, M., 2004. Bruchmechanische Sicherheitsanalyse von Laserstrahlschweissverbindungen. Shaker Verlag.