The size effect on J-R curve for construction steels and its prediction by simplified mechanical model

0495908 - ÚFM 2020 RIV US eng C - Conference Paper (international conference)
Stratil, Luděk - Šiška, Filip - Hadraba, Hynek - Dlouhý, Ivo
The size effect on J-R curve for construction steels and its prediction by simplified mechanical model.
PROCEEDINGS OF THE ASME PRESSURE VESSELS AND PIPING CONFERENCE, 2018,. VOL 6B. New York: ASME, 2019 - (Qian, H.; Brongers, M.; Uddin, M.), č. článku UNSP V06BT06A066. ISBN 978-0-7918-5168-5.
[ASME 2018 - Pressure Vessels and Piping Conference. Prague (CZ), 15.07.2018-20.07.2018]
R&D Projects: GA ČR(CZ) GA17-13573S; GA MŠMT EE2.3.20.0197
Institutional support: RVO:68081723
Keywords : Fracture toughness * J-R curve * P91 * Eurofer97 * size effect * Schindler's model
OECD category: Audio engineering, reliability analysis

Evaluation of mechanical properties from a small amount of test material is essential in a process of development of new alloys and monitoring of degradation and damage of in-service components. Miniaturization of test specimen together with a specimen reconstitution technique enable direct method of evaluation of mechanical properties if only a limited amount of material is available. Modern types of construction steels and alloys possess improved metallurgical and mechanical properties and also demonstrate a high level of fracture toughness. In these cases, correlation and correction of size effect on fracture toughness between different specimen sizes are needed. Within this contribution the size effect of J-R curve for two sizes of three-point-bend specimens is solved. The J-R curves of three-point-bend specimens with cross-section 10×10 mm and 3×4 mm of P91 and Eurofer97 steel were determined at room temperature. The existence of size effect is proven as larger specimens demonstrate higher J-R curves than smaller specimens for both steels. Simplified mechanical model based on fracture energies initially proposed by Schindler et al. is applied to describe experimentally determined J-R curves and to predict the observed size effect between used specimen sizes.
Permanent Link: http://hdl.handle.net/11104/0289507