PSI - Issue 23

A. Karolczuk et al. / Procedia Structural Integrity 23 (2019) 69–76 Author name / Structural Integrity Procedia 00 (2019) 000 – 000 7 Fig. 1). This means that parameter ( ) varies from 0.11 up to 0.42 within the experimental fatigue life range. The concept of life-dependent material parameter ( ) applied to 2124-T851 aluminum alloy considerably improves the consistency of the calculated and experimental fatigue lives (see Fig.3b). The global scatter band factor (0.95) is reduced from 5.7 to 2.0 if the life-dependent material parameter concept is applied. 75

Fig. 3. Comparison of experimental and calculated fatigue lives with the application of the Matake criterion (a) with a constant material parameter; (b) with a life-dependent ( ) material parameter. 5. Conclusions  The constant weight coefficients used by multiaxial fatigue criteria applying at least two material parameters should not be applied to the finite fatigue life calculation since these parameters, in general, should vary with the number of cycles to failure.  Life-dependent material parameters can be applied to stress-, strain- and energy-based multiaxial fatigue models.  The calculated fatigue lives of 2124-T851 aluminium alloy coincide with the experimental data if the Matake criterion is used with life-dependent material parameters.

Acknowledgements

The study presented here was financed from a grant from the National Science Centre, Poland (Decision No. 2017/25/B/ST8/00684). Jan Papuga acknowledges support from ESIF, EU Operational Programme Research, Development and Education, and from the Center of Advanced Aerospace Technology (CZ.02.1.01/0.0/0.0/16_019/0000826), Faculty of Mechanical Engineering, Czech Technical University in Prague.

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