The prediction of size effect on J R curve for Eurofer97 steel by simplified mechanical model

0450456 - ÚFM 2016 RIV US eng C - Konferenční příspěvek (zahraniční konf.)
Stratil, Luděk - Šiška, Filip - Hadraba, Hynek - Dlouhý, Ivo
The prediction of size effect on J R curve for Eurofer97 steel by simplified mechanical model.
ASME 2015 Pressure Vessels and Piping Conference. Boston: ASME, 2015, s. 1-9. ISBN 978-0-7918-5692-5.
[PVP 2015 Pressure Vessels & Piping Conference. Boston (US), 19.07.2015-23.07.2015]
Grant CEP: GA MŠMT EE2.3.20.0197; GA ČR GJ15-21292Y
Institucionální podpora: RVO:68081723
Klíčová slova: Schindler’s model * Eurofer97 * J-R curve * size effect
Kód oboru RIV: JL - Únava materiálu a lomová mechanika

The possibilities to derive fracture toughness from small specimens are naturally limited due to constraint requirements which are especially restrictive in toughness testing. The loss of constraint at the crack tip is more likely to occur as specimen size decreases. Application of miniature specimens in fracture toughness testing thus requires a suitable methodology or correction procedure to deal with phenomenon of the constraint loss. Schindler et al. have proposed a simplified mechanical model that can be used to scale up the key test characteristics from miniature specimen to the larger one. The model is applied to the miniature bending specimens to describe size effect on J R curve of the Eurofer97 steel. The examined steel exhibits quite high toughness values at upper shelf region of fracture toughness. As a result, experimentally determined J R curves of three different sizes of pre cracked bending specimens showed high values of J integral, which were significantly different each other. Using semi empirical definition of the exponent of the power law function of J R curve the performance of the Schindler’s model was quite successful. It was shown that the model is able to handle with size effect of tested pre cracked three point bend specimens.
Trvalý link: http://hdl.handle.net/11104/0252381