PSI - Issue 28

384 J. Serra et al. / Procedia Structural Integrity 28 (2020) 381–392 Author name / Structural Integrity Procedia 00 (2019) 000–000 Where da/dN is the flaw growth rate with cycles in mm/cycle; C and m are constants of Paris Law; Δ is the stress intensity factor range in N/mm 3/2 ; is the geometric factor, Δ is the applied stress range (in N/mm 2 ) for the case of fatigue and is the crack size in mm. The standard BS 7910:2013+A1:2015 provides a solution to the multiplication of the geometric factor and the stress range, � Δ � .     1 w tm km m m tb kb b b m m Y Mf k M M k M M k                 (3) Where the bulging correction factor; � the finite width correction factor; � , �� , � and �� are stress intensity magnification factors, � and � the membrane and bending components of stresses range ( in N/mm 2 ), respectively; �� and �� the membrane and bending stress concentration factors, respectively; and � the stress intensity factor due to misalignment. Expressions for M, f w , M m and M b are given for different types of flaws in different configurations. M km and M kb apply when flaw is in a region of local stress concentration. The stress intensity factor solutions for plates containing surface semi-elliptical flaws and embedded flaws are given by equations from 4 to 9. The bulging correction factor M is equal to 1 for both flaw positions. Equations 5 and 8, applicable up to 2c/W=0.8, given the finite width correction expression, f w , for surface and embedded flaw positions, respectively. Membrane stress intensity magnification factor, M m , is given by the expressions 5 and 8, for surface and embedded flaw positions, respectively. And the equations 7 and 9 represented the bending stress intensity magnification factors, M b , also for the two flaw positions, surface and embedded, respectively. 4

0.5

   

    

0.5



  

c a W B            

sec   

f

(4)

w



2

4

  

   

gf

1 a a M M M M B B               2 3 m



(5)

  

b m M HM 

(6)

0.5

   

    



  

0.5

c a W B             

sec   

f

(7)

w



2

4

  

   

gf

1 a a M M M M B B                   2 3 m



(8)



3 pa B B B                         4 2 p a

     

1 2   

   

M



(9)

b



Where W is the structure half-width in plane of flaw in mm; c is the half flaw length in mm; a is half height for