Page 207 - Biaxial Multiaxial Fatigue and Fracture
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Estimation of the Fatigue Life of High Strength Steel Under ...
1
Ew(t) =-v--o,,(t)
E
1 1
E,(t) =--Yxy(t) =--z,(t)
2 2G
where v is the Poisson’s ratio and G is the shear modulus.
400
\ \
\
300 Tat
Oaf
Nf [cycles]
200 f
1 o4 1 o5 1 o6 1 o7
Fig.3. Exemplary WiShler’s curves for torsion and tension-compression
Having the stress and strain tensor we can determine for push-pull with torsion the normal
stress and strain in any direction of unit vector 3 described by the direction cosines i,,,m,,,fi,,
[2 - 6,8,9,20,22] with respect to the coordinate system of specimen Oxyz (stage 3)
