Modification of a Defect-Based Fatigue Assessment Model for Al-Si-Cu Cast Alloys
AbstractCast parts usually inherit internal defects such as micro shrinkage pores due to the manufacturing process. In order to assess the fatigue behaviour in both finite-life and long-life fatigue regions, this paper scientifically contributes towards a defect-based fatigue design model. Extensive fatigue and fracture mechanical tests were conducted whereby the crack initiating defect size population was fractographically evaluated. Complementary in situ X-ray computed tomography scans before and during fatigue testing enabled an experimental estimation of the lifetime until crack initiation, acting as a significant input for the fatigue model. A commonly applied fatigue assessment approach introduced by Tiryakioglu was modified by incorporating the long crack threshold value, which additionally enabled the assessment of the fatigue strength in the long-life fatigue regime. The presented design concept was validated utilising the fatigue test results, which revealed a sound agreement between the experiments and the model. Only a minor deviation of up to about five percent in case of long-life fatigue strength and up to about 9% in case of finite-lifetime were determined. Thus, the provided extension of Tiryakioglu’s approach supports a unified fatigue strength assessment of cast aluminium alloys in both the finite- and long-life regimes. View Full-Text
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Aigner, R.; Leitner, M.; Stoschka, M.; Hannesschläger, C.; Wabro, T.; Ehart, R. Modification of a Defect-Based Fatigue Assessment Model for Al-Si-Cu Cast Alloys. Materials 2018, 11, 2546.
Aigner R, Leitner M, Stoschka M, Hannesschläger C, Wabro T, Ehart R. Modification of a Defect-Based Fatigue Assessment Model for Al-Si-Cu Cast Alloys. Materials. 2018; 11(12):2546.Chicago/Turabian Style
Aigner, Roman; Leitner, Martin; Stoschka, Michael; Hannesschläger, Christian; Wabro, Thomas; Ehart, Robert. 2018. "Modification of a Defect-Based Fatigue Assessment Model for Al-Si-Cu Cast Alloys." Materials 11, no. 12: 2546.
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