Issue 55

F. Hamadouche et alii, Frattura ed Integrità Strutturale, 55 (2021) 228-240; DOI: 10.3221/IGF-ESIS.55.17

    a i i F K

(1)

where i F is the stress correction factor or form factor, taking into account the geometry of the crack as well as the type of stress applied on the structure, σ is the applied stress, and a is the crack length or the crack depth [20].

Figure 2: Specimen and pad in complete contact

E QUIVALENT DOMAIN INTEGRAL (EDI)

T

he integral J is a measure of variation of potential energy, which in linear elasticity, can be directly related to the stress intensity factor SIF [21]:



 

u x





j



 Wdx t (

J

d

(2)

Г )

Г

i

2

1

W is the strain energy density, Г is the contour around the end of the crack,  i t =  ij j n . For an elastic material, this integral is identical to the rate of energy release G [19] contour, i t stress vector given by 

i u displacement vector at a point of the

        2 2 2 ' ' 2 I II III T I II III K K K J G G G G E E

(3)

where:

E'=E in plane constraints

(4)

  2 1 E

in plane deformation

(5)

E'=

   2 1 E

is the shear modulus

(6)

µ = 

The Equivalent Domain Integral method use all the area A* showed in Fig.3, it is well applied to solve problems of solid in 3D with crack [18].

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