Page 505 - Biaxial Multiaxial Fatigue and Fracture

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Fig. 3. Anticlastic bending fixtures.

Material
The material used in this programme was a commercial aviation graded aluminium alloy 2024-
T351. This material was chosen to further validate the subsurface model that was previously
used only with a structural steel (EN15) [19], and it was more suitable for the development of
the new testing facility since it has a lower strength in comparison to the structural steel.
The monotonic and cyclic mechanical properties of the aluminium al 2024-T351 are listed
in Table 2. Fatigue properties for this material were obtained from the literature [22]. A cyclic
stress-strain curve of the material was used for the elastic-plastic fatigue analysis instead of the
monotonic response.
Table 2. Estimated material properties for the AI 2024 -T351 from [22]

Property Symbol Value Unit
Yield Strength 00 379 MPa
Ultimate Strength 0, 455 MPa
Cyclic Elastic Modulus E 73100 MPa
Cyclic Strength Coefficient H' 662 MPa
Strain Hardening Exponent n' 0.070
Fatigue Strength Coefficient 0; 927 MPa
Fatigue Strength Exponent b -0.113
Fatigue Ductility Coefficient E; 0.409
Fatigue Ductility Exponent c -0.713