Determination of fatigue crack growth in the near-threshold regime using small-scale specimens

0557098 - ÚFM 2023 RIV NL eng J - Článek v odborném periodiku
Blason, S. - Werner, T. - Kruse, J. - Madia, M. - Miarka, Petr - Seitl, Stanislav - Benedetti, M.
Determination of fatigue crack growth in the near-threshold regime using small-scale specimens.
Theoretical and Applied Fracture Mechanics. Roč. 118, APR (2022), č. článku 103224. ISSN 0167-8442. E-ISSN 1872-7638
Grant CEP: GA ČR(CZ) GA20-00761S
Institucionální podpora: RVO:68081723
Klíčová slova: tensile * Fatigue crack growth * Small-scale specimens * Intrinsic fatigue propagation threshold * Near-threshold regime * High-strength steel * Alternative test procedure
Obor OECD: Construction engineering, Municipal and structural engineering
Impakt faktor: 5.3, rok: 2022
Způsob publikování: Omezený přístup
https://www.sciencedirect.com/science/article/pii/S0167844221003207?via%3Dihub

A complete description of the experimental procedure for characterizing the intrinsic fatigue crack propagation threshold (delta(Kth,eff)) as well as the fatigue crack growth rate (FCGR) in the near-threshold regime using small-scale specimens is presented. A comparative study is carried out on the high strength steel S960QL considering different single edge notch bend (SENB) specimen geometries. On one hand, the reference dimensions of 6 mm thickness (B) and 19 mm width (W) are analysed and referred to as conventional specimens. On the other hand, small-scale specimens with B = 3 mm and W = 4 and 6 mm are also considered. Several loading configurations (3, 4-and 8-point bending) are used and a load ratio R = 0.8 is applied to avoid crack closure effects. The direct current potential drop (DCPD) technique is used to monitor the crack length. The reduced dimensions of the small-scale specimens imply the necessity of implementing a modified testing procedure compared to the recommendations of current standards for the generation of FCGR data. The results show a good agreement between tests conducted on different specimen sizes, which opens new perspectives in the use of small-scale specimens for characterizing the fatigue crack growth properties in metallic materials. Recommendations and limitations of the procedure are provided and discussed.
Trvalý link: http://hdl.handle.net/11104/0331179