max] is the maximum nominal stress
applied on the specimen) is used.
displacement curve acquired, the nominal stress
0] = s, s is the initial nominal stress
(initial load of one LI), [[?
nom] is the nominal stress
calculated by equation [[sigma].
A theoretical, or geometrical, stress concentration factor Kt or Kts is used to relate the actual maximum stress at the discontinuity to the nominal stress
The regression equations of S-N curves (applied nominal stress
In view of equation (33), the nominal stress
, S say, will then be represented in a particularly convenient form by
Global features such as nominal stress
, excess compliance, and fastener load are connected with local conditions that affect fatigue and fretting, including contact pressures, interface slips, residual stresses, and the intensity and location of the stress concentrations.
The nominal stress
approach cannot be used for complex component geometries, because nominal stress
cannot be defined explicitly for complex geometries.
Woehler then plotted the nominal stress
versus the number of cycles to failure, which came to be known as the SN diagram, and it is still widely used today.
Then repeatable nominal stress
was difficult to be determined within a range of smaller nominal strain.
Starting from the hypothesis that the theory of critical distances is useful for the prediction of fracture for the problems where the nominal stress
field is linear-elastic (high cycle fatigue, ceramic materials fracture), respectively the strains are elastic, excepting of a small area at the concentrator tip, the possibility of applying thid theory for the fracture of polymetric materials was studied (Taylor et al.