The effect of notch depth on CTOD values in fracture tests of structural steel elements

• Autorzy: Kowalski J. , Kozak J.

Identyfikatory

DOI

10.2478/pomr-2018-0058

• Języki publikacji: EN

Abstrakty

EN

In elements of steel structures working at low temperatures, there is a risk of appearance of brittle fracture. This risk is reduced through the use of certified materials having guaranteed strength at a given temperature. A method which is most frequently used to determine brittle fracture toughness is the Charpy impact test, preformed for a given temperature. For offshore structures intended to work in the arctic climate, the certifying institutions more and more often require Crack Tip Opening Displacement (CTOD) tests instead of conventional impact tests, especially for steel and welded joints of more than 40 mm in thickness in the case of high-strength steel, and more than 50 mm for the remaining steels. The geometry of specimens and the test procedure are standardised; however, these standards provide some margin for specimen notch depth. The paper analyses the effect of notch depth difference, within the range permitted by the standards, on the recorded CTOD values of a given material. The analysis was performed via numerical modelling of destruction of specimens with different notch geometries and further verification of the obtained numerical results in laboratory tests. The calculations were carried out at the Academic Computer Centre in Gdansk.

Słowa kluczowe

EN

brittle fracture; CTOD; numerical modelling; laboratory tests

• Wydawca: Gdańsk University of Technology, Faculty of Ocean Engineering & Ship Technology
• Czasopismo: Polish Maritime Research
• Rocznik: 2018
• Tom: nr 2
• Strony: 85--91
• Opis fizyczny: Bibliogr. 15 poz., rys., tab.

Twórcy

autor

Kowalski J.

• Gdansk University of Technology Faculty of Ocean Engineering and Ship Technology Narutowicza 11/12 80-233 Gdansk Poland

autor

Kozak J.

• Gdansk University of Technology Faculty of Ocean Engineering and Ship Technology Narutowicza 11/12 80-233 Gdansk Poland

Bibliografia

• 1. S. Kocańda and J. Szala, Fundamentals of fatigue calculations (in Polish), Warsaw: Wydawnictwo Naukowe PWN, 1997.
• 2. ASTM, E23 – 16b Standard Test Methods for Notched Bar Impact Testing of Metallic Materials, West Conshohocken (PA): ASTM International, 2016.
• 3. Polish Committee for Standardisation, PN-EN ISO 148-1:2017-02 Metals – Charpy impact test – Part 1: Test method (in Polish), Warsaw: Polish Committee for Standardisation, 2017.
• 4. Polish Register of Shipping, Rules for the Classification and Construction of Sea-going Ships, Part IX – Materials and Welding (in Polish), Gdansk: Polish Register of Shipping, 2017.
• 5. J. R. Rice i D. M. Tracey, “On the ductile enlargement of voids in triaxial stress fields,” in J. Mech. Phys. Solids, 17, 1969.
• 6. EEMUA, Publication 158 Construction Specification for Fixed Offshore Structures In The North Sea, Londyn: The Engineering Equipment And Materials Users’ Association, 2014.
• 7. G. Sih, “Methods of analysis and solutions of crack problems, Vol1.,” Noordhoff Int. Publishing, Leyden, ISBN 9001798608., 1973.
• 8. W. T. Bao Y., “A Comparative Study on Various Ductile Crack Formation Criteria,” in Transactions of the ASME, Vol. 126, 2004.
• 9. British Standard, BS 7448-1:1991 – Fracture mechanics toughness tests. Method for determination of KIc, critical CTOD and critical J values of metallic materials, London: BSI, 1991.
• 10. ISO, ISO 12135 Metallic materials – Unified method of test for the determination of quasi-static fracture toughness, Geneva: Polish Committee for Standardisation, 2002.
• 11. A. Neimitz, Fracture Mechanics (in Polish), Warsaw: Wydawnictwo Nakowe PWN, 1998.
• 12. British Standard, BS 7910:2005 Guide to methods for assessing the acceptability of flaws in metallic structures, Londyn: BSI, 2005.
• 13. NORSOK STANDARD, M-101, Structural steel fabrication, Lysaker: Standards Norway, 2011.
• 14. Polish Committee for Standardisation, PN-EN ISO 15653:2010 Metallic materials – Test method to determine quasi-static brittle fracture toughness of welds (in Polish), Warsaw: Polish Committee for Standardisation, 2010.
• 15. Dassault Systèmes, Abaqus 6.14 Documentation, Providence, RI: Dassault Systèmes, 2014.

Uwagi

PL

Opracowanie rekordu w ramach umowy 509/P-DUN/2018 ze środków MNiSW przeznaczonych na działalność upowszechniającą naukę (2018).