Fatigue Crack Paths 2003

Figure 3. External longitudinal-like (a)-(c) and transversal-like (d)-(f) surface fl a win a

notched shell (sizes in mm).The coloured area indicates the notch location.

W101) :Kuo/ (%frn) J5)

(3)

whereore/[0,) : 1 and KKn), related to the n-th load case, is obtained froma F Eanalysis.

A napproximate expression of the dimensionless SIF for a complexstress distribution,

o'1(L) (w), where the subscript (L) indicates the generic load case, is given by [8]:

_ _ 16

(4)

K *1(L) — qrefu) ‘2.03am ‘K *I(n)

with the coefficients BML) expressed by :

B (L) _an. i d w a l u fl w )

(5)

n _

d(w)(n)

n!

whereas o'ref(L) is the reference stress for the the generic load case (L) considered.

In the following, two particular shells (cylindrical and spherical) subjected to an

internal pressure are examined.