TY - CONF A1 - Duarte, Larissa A1 - Madia, Mauro A1 - Zerbst, Uwe T1 - The use of effective fatigue crack propagation data obtained at closure-free conditions for component assessment N2 - The knowledge of fatigue crack propagation data in terms of their effective values is important for a conservative and safe life assessment of components subjected to cyclic loading. To overcome issues related to the precise consideration of the crack-closure effects on experimental data obtained at small R ratios, closure-free data have been obtained at R ≈ 0.8 by different experimental procedures. The statistical analysis of the intrinsic fatigue crack propagation threshold obtained experimentally has shown a small data scatter and good agreement between procedures. When compared with effective values obtained from analytical corrections of closure-affected data, the data obtained at R ≈ 0.8 should lead to a conservative life estimation. T2 - 43rd International Conference on Materials Mechanics CY - Sani, Greece DA - 05.06.2022 KW - Component assessment KW - Effective crack propagation data KW - Experimental procedure KW - Crack-closure PY - 2022 SP - 104 EP - 108 AN - OPUS4-56851 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zhu, Jiangchao A1 - Madia, Mauro A1 - Schurig, Michael A1 - Fedelich, Bernard A1 - Schlums, H. A1 - Zerbst, Uwe T1 - Burst Behaviours Of Aero Engine Turbine Disk At Overspeed Conditions N2 - Aero-engine turbine disks are safety-relevant components which are operated under high thermal and mechanical stress conditions. The actual part qualification and certification procedures make use of spin-tests conducted on production-similar disks. The aim of this work is to present part of a fracture mechanics-based procedure under development which aims at replacing the tests on production-similar disks with lab tests on fracture mechanics specimens. The finite element simulation of the cracked disk considers the real thermal and mechanical loading conditions. In order to design a lab representative specimen, beside the crack driving force, expressed in terms of 𝐽-integral, also the constraint to plastic deformation e.g., stress triaxiality, at the crack-tip must be similar for the same crack in the specimen and in the disk. This has been achieved and as expected, both the highest 𝐽 -integral and constraint factor are calculated at the same location along the crack front for both disk and specimen. The results of the structural integrity assessment in the form of a Failure Assessment Diagram (FAD) show good agreement between designed specimen and disk both in terms of expected failure mode and value of the critical speed. In addition, probabilistic aspects are also considered in the calculations. T2 - 43rd Int. Conference on Materials Mechanics, June 5-10, 2022, Greece CY - Sani, Chalkidiki, Greece DA - 05.06.2022 KW - Structural integrity KW - Turbine disk KW - Fracture mechanics KW - Overspeed PY - 2022 SP - 1 EP - 13 AN - OPUS4-57279 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -