PSI - Issue 2_A

Uwe Mayer / Procedia Structural Integrity 2 (2016) 1569–1576

1576

Uwe Mayer / Structural Integrity Procedia 00 (2016) 000 – 000

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of the reference temperature T 0,X is biased by a negative shift if test temperature is higher than the reference temperature and by a positive shift if test temperature is lower than the reference temperature. The presented results with loading rates in the range of 10 5 -10 6 MPa√m s -1 showed that the sensitivity to the loading rate requests a more precise definition. Proposed is the use of two digits of the common logarithm of the loading rate instead of only one.

4. Outlook

In numerical simulations we are going to analyze the correlation of the local strain, stress and temperature behavior during high rate loading and the impact on the probability of failure in more detail. In future research projects the conclusions found here should be confirmed for other steels and weld material. With this knowledge quantitative modifications to ASTM E1921 can be implemented.

Acknowledgements

The research project “Analysis and Validation of Fracture Mechanical Assessment Methods under Dynamic Loading” is funded by the German Federal Ministry for Economic Affairs and Energy (Project No. 1501472B) on the basis of a decision by the German Bundestag. The project is a cooperation of Fraunhofer Institute for Mechanics of Materials, IWM, Freiburg and Materials Testing Institute University of Stuttgart, MPA, Germany.

References

ASTM E399-12, 2012 . “Standard Test Method for Linear -Elastic Plane-Strain Fracture Toughness K IC of Metallic Materials,” ASTM International, American Society for Testing and Materials, West Conshohocken, PA, USA. ASTM E 1221-12, 2012. “ Standard Test Method for Determining Plane-Strain Crack-Arrest Fracture Toughness, K Ia , of Ferritic Steels ” , ASTM International, American Society for Testing and Materials, West Conshohocken, PA, USA. ASTM E1820-15a, 2015. “Standard Test Method for Measurement of Fracture Toughness,” ASTM International, American Society for Testing and Materials, West Conshohocken, PA, USA. ASTM E1921- 15a, 2015. “Standard Test Method for Determination of Reference Temperature, T 0 , for Ferritic Steels in the Transition Range,” ASTM International, American Society for Testing and Materials, West Conshohocken, PA, USA. BS 7448-3:2005, 2005. Fracture Mechanics Toughness Tests, Part. Method for Determination of Fracture Toughness of Metallic Materials at Rates of Increase in Stress Intensity Factor Greater than 3.0 MPa∙m 0.5 s -1 , BSI. Böhme, W., Mayer, U., Reichert, T, Offermanns, S., Allmendinger, A., Hug, M., Schüler, J. and Siegele, D., 2012. “Überprüfung und Weiter entwicklung von Bewertungsmethoden für dynamische Rissinitiierung und Rissarrest, (Verification and further development of assessment methods for dynamic crack initiation and crack arrest),” BMWi -Vorhaben Nr. 150 1368. Böhme, W., Reichert, T. and Mayer, U., 2013. „Assessment of dynamic fracture toughness values K Jc and reference temperatures T 0,X determined for a German RPV steel at elevated loading rates according to ASTM E1921“, 22nd Int. Conf. on Structural Mechanics in Reactor Technology, SMiRT-22, San Francisco, USA, August 18-23, 2013. Mayer, U., 2012 . “Determination of Dynamic Fracture Toughness at High Loading Rates, ”Proceedings of the ASME 2012 In ternational Mechanical Engineering Congress & Exposition”, IMECE2012 -85383, Houston, Texas, USA, November 9-15, 2012. Mayer, U., Offermanns, S., 2013. “Definition of Loading Rate and Effects on Determination of Dynamic Fracture Toughness and Transition Temperature T 0,X according to ASTM E1921 at elevated Loading Rates, SMiRT-22, San Francisco, California, August 18-23, 2013. Mayer, U., 2015. “Considering the Statistical Distribution of Dynamic Fracture Toughness Data and the Actual Loading Rate at Fracture Initiation when applying ASTM E1921 at Elevated Loading Rates”, 15th International ASTM/ESIS Symposium on Fatigue and Fractur e Mechanics (40th National Symposium on Fatigue and Fracture Mechanics), Anaheim, CA, USA, May 20-22, 2015. Roos, E., Eisele, U., Lammert, R., Restemeyer, D., Schuler, X., Seebich, H.-P., Seidenfuß, M., Silcher, H. and Stumpfrock, L., 2006. „Kritische Überprüfung des Masterkurven- Ansatzes im Hinblick auf die Anwendung bei deutschen Kernkraftwerken“, Forschungsvorhaben BMWi FKZ 1501240, Abschlussbericht MPA Stuttgart. Schindler, H. J. and Kalkhof, D., 2013. “Lower bounds and saturation effects of dynamic fracture toughness in the brittle-to ductile transition regime of ferritic steels”, 22nd Int. Conf. on Structural Mechanics in Reactor Technology, SMiRT-22, USA, August 18-23, 2013. Wallin, K., Rintamaa, R. 1998, “Master Curve based Correlation between Initiation Toughness K IC and Crack Arrest Toughness K Ia 24 th MPA Seminar, Stuttgart, October 8 and 9, 1998. Wallin, K., 2011, “ Fracture Toughness of Engineering Materials – estimation and application, EMAS Publishing, Warrington, UK.