TY - JOUR A1 - Pourheidar, A. A1 - Patriarca, L. A1 - Madia, Mauro A1 - Werner, Tiago A1 - Beretta, S. T1 - Progress in the measurement of the cyclic R-curve and its application to fatigue assessment JF - Engineering fracture mechanics N2 - The cyclic R-curve describes the resistance of a material to fatigue crack propagation fromthe short to the long crack regimes and it is therefore an essential ingredient in any fracturemechanics-based fatigue assessment procedure. This work presents different testing proceduresemployed in the experimental determination of the cyclic R-curve, especially focusing onthe comparison with long fatigue crack propagation thresholds obtained by means of thecompression precracking load reduction (CPLR) procedure. The tests were performed on theEA4T steel considering different stress ratios. The results show a good reproducibility of thecyclic R-curves at every stress ratio and for any testing procedure. In addition, the cyclicR-curves were used in a fracture mechanics-based assessment to predict the fatigue limits ofspecimens containing micro-notches. KW - Cyclic R-curve KW - Fatigue limit KW - Fatigue propagation threshold KW - EA4T steel KW - Digital image correlation PY - 2022 DO - https://doi.org/10.1016/j.engfracmech.2021.108122 SN - 0013-7944 VL - 260 SP - 1 EP - 17 PB - Elsevier CY - Kidlington AN - OPUS4-54208 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Bergant, M. A1 - Werner, Tiago A1 - Madia, Mauro A1 - Yawny, A. A1 - Zerbst, Uwe T1 - Short crack propagation analysis and fatigue strength assessment of additively manufactured materials: An application to AISI 316L JF - International Journal of Fatigue N2 - This paper presents the application of short crack propagation models based on the cyclic R-curve for assessing the fatigue strength of additively manufactured (AM) materials containing fabrication defects. Chapetti’s and IBESS models were implemented in combination with Murakami’s √area parameter, considering recently published data on laser powder bed fusion processed AISI 316L stainless steels. Estimated S-N curves and Kitagawa-Takahashi diagrams predict fairly well the experimental data, especially the origin of the failure from internal or surface defects. These results provide an indication that the methods based on the cyclic R-curve constitute suitable tools for fatigue behavior assessment of AM materials. KW - AM 316L stainless steel KW - Cyclic R-curve KW - Chapetti’s and IBESS model KW - S-N curve KW - Kitagawa-Takahashi diagram PY - 2021 DO - https://doi.org/10.1016/j.ijfatigue.2021.106396 VL - 151 PB - Elsevier Ltd. AN - OPUS4-53082 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -