Due to the severe operational environment, gas turbine engine structural components are usually required to be designed using lifetime failure-free criterion, with the use of tools such as the Goodman diagram and the modified Goodman diagram which are usually constructed using uniaxial fatigue data. The Goodman diagram is a plot of alternating stress versus mean stress and represents the fatigue properties of a given material for a given number of cycles. Typical uniaxial fatigue tests on a servohydraulic tensile test machine operate at 60 Hz, requiring approximately 46 h to accumulate 107 cycles for each data point on the Goodman diagram. Therefore, significant amounts of time are required to characterize the fatigue properties of typical aerospace structural materials. To address this concern, a novel vibration-based fatigue testing concept was proposed for assessing turbine engine material fatigue strength. The idea is to accumulate stress cycles on a base-excited plate specimen at high-frequency resonant modes such as the two-stripe mode (frequency range: 1200 Hz - 1600 Hz), frequencies that cannot be achieved in conventional fatigue test machines. This goal can be achieved in three steps: (1) a geometrical design procedure, incorporating a finite element model, to characterize the shape of the specimen for ensuring the required stress state/pattern; (2) a vibration feedback empirical procedure for achieving the high-cycle fatigue (HCF) experiments with variable-amplitude loading; and (3) a pre-strain procedure for achieving various uniaxial stress ratios. The performance of the methodology is demonstrated with experimental results for mild steel, 6061-T6 aluminum, and Ti-6Al-4V plate specimens subjected to a fully reversed bending, uniaxial stress state.
Goodman diagram via vibration-based fatigue testing
Goodman-Diagramm über die schwingungsbasierte Ermüdungsprüfung
2005
7 Seiten, 13 Bilder, 7 Tabellen, 8 Quellen
Article (Journal)
English
British Library Conference Proceedings | 2016
|To goodman Chappels supplication
GWLB - Gottfried Wilhelm Leibniz Bibliothek | 1552
|To goodman Chappels supplication
TIBKAT | 1552
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