Issue 14

M.N

. James et alii,

Frattura ed Inte

grità Strutturale

, 14 (2010) 5-1

6; DOI: 10.3221/

IGF-ESIS.14.01

   

 iv       2 B E z  

1 2

1

1 2

C Ez lnz 

F z

 2 u    z    Az   

  2 2 B E z 

2 4 Ez  

2

4

4 C F z     

1/2

1/2 Ez ln  

(5)

2 C F z    

1/2

1/2 Dz ln 

1/2 2 z Dz  

wh   u,v   z A, Cas exa K S , fou

ere:

= s = f = h = a = c = u

hear modulu unction of Po orizontal and uxiliary funct omplex coor nknown coe ese terms allo correlation t llows (note t -direction an

s, MPa isson’s ratio vertical disp ions in Musk dinate in the fficients and ws direct co echniques (F hat when usi d T y in y-dire

ν lacements

   , z z  B, C, D, E , F ting the CJP mple, using K R and the T nd as compo

helishvili‘s m plane z=x+iy D+E = 0 mparison wi ig. 1). Expr ng displacem ction):

odel

model in th digital image -stress as fo nents T x in x

th full field c essions can b ent data rath

rack tip disp e directly ob er than stres

lacement fiel tained from s data, the T

ds measured, Eq. 5 giving -stress has to

for K F , be

Figure 1 : full-fiel

Displacement d fitting betwe a crack 29.3

field around a en model and mm long und

crack tip mea experimental er a load of 12

sured using D data. A 2 mm 0 N. The mea

IC techniques thick alumini surement regi

. The pattern um specimen i on is 17.7 mm

of points is us s used which c by 13.2 mm.

ed for the ontains

  



  

1 2

 2 A B 



 

 8 E

K

r

Er l

n r

l im 2 

2

3  











I

y



r

0



(6)











 

 

r  

A B 

K

l im 2





xy

S r

2

0



3

2 

 r  







 

 

3 D E 

K

l    R r

im 2

x

0



C

T T

X

F

 

y

It i pla

s not yet clea sticity-induce

r whether th d growth rat

e CJP mode e perturbatio

l, based on t ns, or lead to

he plastic inc a reconcilia

lusion conce tion of confl

pt, will prov icting views

ide a means of plasticity-i

sing tip

of characteri nduced crack

8