non-planar interface crack under general loading ii. … · rev. ivoir. sci. technol., 30 (2017) 1...

36
Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 1 ISSN 1813-3290, http://www.revist.ci P. N. B. ANONGBA NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. CLIMB-TYPE SINUSOIDAL EDGE DISLOCATION P. N. B. ANONGBA U.F.R. Sciences des Structures de la Matière et de Technologie, Université F.H.B. de Cocody, 22 BP 582 Abidjan 22, Côte d’Ivoire _______________________ *Correspondance, e-mail : [email protected] ABSTRACT This study's objective is to analyse the conditions of propagation of an oscillatory front crack along a non-planar interface, under mixed mode I + II + III loading. The crack model consists of a continuous distribution of three families of non-straight dislocations having the shape of the crack front : families 1 and 2 are edges (on average) and family 3 is screw. The associated Burgers vectors j b (j=I, II, III) are directed along the applied tension and shears 2 x , 1 x and 3 x directions, respectively. The dislocations are aligned along the 3 x direction and spread in 3 2 x x planes in a small oscillating form ) , ( 3 1 x x at an average elevation ) ( 1 x h . It is sufficient to investigate a simpler model where the interface is in the form of a corrugated sheet and the dislocations have a sinusoidal form. The first part I of this study has provided expressions for the displacement and stress fields of sinusoidal dislocations with I b (glide-type edges) and III b (screws). Those ) ( m u and ) ( ) ( m of dislocation family 2 with II b (climb-type edges) are the subject of this part II. It is shown that in order to guarantee conditions of continuity of the elastic fields at the crossing of the interface, the relative variation of volume must be continuous at the crossing of the interface with well-defined non-zero values which depend on Poisson’s ratios. This results in an estimated mismatch, far from the interface, between the displacements ) ( m u and ) ( m u ; the latter corresponding to the field due to the same dislocation in a totally homogeneous medium. Keywords : linear elasticity, interface dislocations, Galerkin vector, three- dimensional biharmonic functions, Fourier forms, linear systems of equations.

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Page 1: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 1 ISSN 1813-3290, http://www.revist.ci

P. N. B. ANONGBA

NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING

II. CLIMB-TYPE SINUSOIDAL EDGE DISLOCATION

P. N. B. ANONGBA

U.F.R. Sciences des Structures de la Matière et de Technologie, Université

F.H.B. de Cocody, 22 BP 582 Abidjan 22, Côte d’Ivoire

_______________________

*Correspondance, e-mail : [email protected]

ABSTRACT

This study's objective is to analyse the conditions of propagation of an

oscillatory front crack along a non-planar interface, under mixed mode I + II +

III loading. The crack model consists of a continuous distribution of three

families of non-straight dislocations having the shape of the crack front :

families 1 and 2 are edges (on average) and family 3 is screw. The associated

Burgers vectors j

b

(j=I, II, III) are directed along the applied tension and shears

2x ,

1x and

3x directions, respectively. The dislocations are aligned along the

3

x direction and spread in 32

xx planes in a small oscillating form ),(31

xx

at an average elevation )(1

xh . It is sufficient to investigate a simpler model

where the interface is in the form of a corrugated sheet and the dislocations

have a sinusoidal form. The first part I of this study has provided expressions

for the displacement and stress fields of sinusoidal dislocations with I

b

(glide-type edges) and III

b

(screws). Those

)( mu

and )(

)(m

of dislocation family

2 with II

b

(climb-type edges) are the subject of this part II. It is shown that in

order to guarantee conditions of continuity of the elastic fields at the crossing

of the interface, the relative variation of volume must be continuous at the

crossing of the interface with well-defined non-zero values which depend on

Poisson’s ratios. This results in an estimated mismatch, far from the interface,

between the displacements )( m

u

and )( m

u

; the latter corresponding to the field

due to the same dislocation in a totally homogeneous medium.

Keywords : linear elasticity, interface dislocations, Galerkin vector, three-

dimensional biharmonic functions, Fourier forms, linear systems

of equations.

Page 2: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

2 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

RÉSUMÉ

Fissure d'interface non plane sous sollicitation extérieure arbitraire

II. Dislocation coin de type montée

La présente étude se fixe pour objectif d'analyser les conditions de propagation

d'une fissure de front oscillatoire le long d'une interface non plane sous

sollicitation en mode mixte I+II+III. Le modèle de fissure adopté, est une

distribution continue de trois familles de dislocations non rectilignes ayant la

forme du front de fissure : les familles 1 et 2 sont des coins (en moyenne) et la

famille 3 est vis. Les vecteurs de Burgers infinitésimaux associés j

b

(j= I, II, III) sont suivant les directions2

x , 1

x et 3

x , correspondant à la tension

et aux cisaillements appliqués, respectivement. Les dislocations sont suivant la

direction 3

x et s'étalent dans les plans 32

xx dans la forme ),(31

xx à la hauteur )(1

xh

. Il suffit d’analyser un modèle de fissure plus simple dans lequel l’interface a la forme

d’une tôle ondulée et les dislocations sont sinusoïdales. La première partie de cette

étude a fourni les expressions des champs de déplacement et contrainte des

dislocations sinusoïdales avec I

b

(coins de type "glissile") et

IIIb

(vis). Ceux de la

famille 2 avec II

b

(coins de type "montée") sont l’objet de cette partie II. On montre

que, dans le but de garantir la continuité des champs élastiques à la traversée de

l’interface, la variation relative de volume doit être continue au passage de l’interface

avec une valeur bien définie, non nulle, laquelle dépend des rapports de Poisson des

milieux environnants. Il en résulte un écart estimé, loin de l’interface, entre les

déplacements )( m

u

et )( m

u

; le dernier correspondant aux champs de la même

dislocation dans un milieu totalement homogène.

Mots-clés : élasticité linéaire, dislocations d'interface, Vecteur de Galerkin,

fonctions biharmoniques à trois dimensions, expansions en séries

de Fourier, systèmes d'équations linéaires.

I - INTRODUCTION

This study is involved with the determination of the elastic fields of a

non-planar interface crack model in equilibrium under an externally applied

general loading. The model of crack and its pertinence to represent large real

cracks have been introduced in part I of this work [1] ; it consists of two

infinitely extended elastic mediums R1 and R2 firmly welded along a

non-planar interface R (Figure 1). With respect to a Cartesian coordinate

systemi

x , the crack extends from ax 1

to a, fluctuates on average about

31xOx -plane; its front runs indefinitely in the

3x - direction and spreads in

32

xx planes in the Fourier series form f, written as

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Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3

P. N. B. ANONGBA

hhxxf

n

nnnn

33cossin (1)

where n is a positive integer; h, n

, n

and n

are real numbers that depend

on position 1

x along the crack length. The system is subjected to remote applied

Figure 1 : Schematic illustration of the crack front in two elastic solids (1)

and (2) welded along a non-planar wavy surface that contains an

interface crack. The crack fronts lie in 32

xx planes in the form f

(1); in this geometry, the system is subjected to mixed mode I+II+III

loading with the applied tension in the 2

x direction. The average

fracture surface (dashed) is shown perpendicular to that direction

general loading, corresponding to a tension along2

x , and two shears

(parallel to 31

xx ) directed along1

x and3

x , respectively. Our method of analysis

consists in representing the crack by a continuous distribution of three families

of non-straight infinitesimal dislocations having the form f. Families 1 and 2

are edges (on average) and family 3 is screw. The associated Burgers vectors

jb

(j=I, II, III) are directed along the applied tension and shears

2x ,

1x and

3x

directions, respectively. It is sufficient to investigate a simpler model where the

interface is in the form of a corrugated surface S and the dislocations have a

sinusoidal form n

A given by

3sin xA

nnn . (2)

The applied loadings and dislocation Burgers vectors are unchanged. The case

of a general shape, with crack front f (1), is achieved by superposition [1]. From

the elastic fields of the dislocations, the crack-tip stress and crack extension

force can be evaluated. Such analyses, with variable complexity of the crack

front, exist in the case of an infinitely extended isotropic medium ([2 - 9],

Page 4: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

4 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

among others). We plan to extend the analysis to non-planar interface cracks

under general loading (mixed mode I+II+III). The first part I of this study [1]

has provided expressions for the displacement and stress fields of sinusoidal

dislocations with I

b

(glide-type edges) and

IIIb

(screws). Those of dislocation

family 2 with II

b

are the subject of this part II. For the various types of

dislocation, the general geometry is that of Figure 2; because )0,0,(bbII

is

out of the 32

xOx –plane of location of the dislocation, this is a climb-type edge.

In what follows, the methodology and elastic field expressions form Section 2

and 3, respectively. Discussion and conclusion form Section 4 and 5

respectively. The third part III of the work will deal with crack-tip stresses and

crack extension force when the non-planar interface crack is loaded in mixed

mode I+II+III.

II - METHODOLOGY

We seek the elastic fields of a dislocation ( )0,0,(bbII

) lying on a non-planar

interface S having the form of a corrugated sheet that separates two firmly

welded elastic solids S1 and S2 of infinite sizes. S is defined by the point

),sin,(3321

xxxxPnnS

and S1 and S2 occupy the regions 32

sin xxnn

and32

sin xxnn

, respectively. The situation is shown in Figure 2 where S1

and S2 are confined for illustration purpose in a parallelepiped of finite sizes.

The dislocation is located at the origin, runs indefinitely in the 3

x direction

and spreads in the 32

xx plane in the formn

A (2).

Figure 2 : Two elastic mediums (1) and (2) welded along a non-planar

sinusoidal surface and containing an interface sinusoidal

dislocation at the origin. The dislocation lies in the 32

xOx

plane in the formn

A and runs indefinitely in the 3

x direction

Page 5: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 5

P. N. B. ANONGBA

The methodology has been detailed in different places [1, 10, 11]. The elastic

fields ( )( mu

, )()(

m ) are assumed to be the difference between two quantities

( )( mu

, )()(

m ) and ( Wm

u)(

, Wm )()( ):

Wmmm

Wmmmuuu

)()()(

)()()(

)()()(

. (3)

The former with corresponds to the fields of a sinusoidal dislocation

(edge or screw) in an infinitely extended homogeneous solid (m); the latter with

W satisfies the equations of equilibrium and is constructed in such a way that :

(a) ( )( mu

, )()(

m ) are continuous at the crossing of the interface, implying that

)()()1()2()1()2(

S

WWW

SPuuuuuPu

)()()()()()()()()1()2()1()2(

S

WWW

SPP

; (4)

(b) ( )( mu

, )()(

m ) tends to ( )( m

u

, )()(

m ) when one moves far away from the

interface in the 2

x direction. This means that

0)(

0

)(

)(

Wm

Wmu

(5)

when 2

x . ( )( mu

, )()(

m ) may be taken from [6, 7]; they are given to linear

expressions with respect ton

. The associated terms ( ))(0( mu

, ))(0()(

m ) of zero

order correspond to the fields of a straight dislocation and second terms ( )( mAnu

,

)()(

mAn ) are proportional to either

nA or its spatial derivative

3/ xA

n . Hence, we

have

n

n

A

S

A

S

P

uuPu

)()()()(

)(

)0(

)0(

(6)

on the interface point ),sin,(3321

xxxxPnnS

; Appendix A below gives the

complete list, component by component, for the climb-type sinusoidal edge dislocation; the corresponding values for the glide-type edge and screw sinusoidal

dislocation have been given in [1, 10, 11]. ( Wmu

)(, Wm )(

)( ) are obtained with the

help of Galerkin vectors; these are available for the glide-type edge and screw

(see [1, 10, 11]). For the climb-type sinusoidal edge, we arrive at Galerkin vectors

V

with only one non-zero

1x component, arranged in the form

xkixkiexkekxV

.

21

.

11)()()( (7)

Page 6: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

6 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

under the condition 02

3

2

2

2

1

2 kkkk

that ensures the biharmonicity of

1V .

For 1

V to cancel far from the interface, we write

2

3

2

1

1)(

22)1( kkikk

mm

(8)

with 1m when 32

sin xxnn

(half-space 1) and 2m when

32sin xx

nn (half-space 2). We use the notations

),,(3

)(

21

)(kkkk

mm

, )(

)(

1

)(

1

mmk

, )(

)(

1

)(

1

mmk

;

hence for half-space 1 (32

sin xxnn

), solid (1)

xkixkiexexVxV

.

2

)1(

1

.)1(

1

)1(

11

)1()1(

)()(

and for half-space 2 (32

sin xxnn

), solid (2)

xkixkiexexVxV

.

2

)2(

1

.)2(

1

)2(

11

)2()2(

)()( .

The elastic fields corresponding to 1

V (7) may be first calculated; then, more

general forms Vmu

)( and Vm )(

)( are constructed from the previous ones by

superposition over 1

k and 3

k ; we may write

BAmBmAmVm

BAmBmAmVmuuuu

)()()()(

)()()()(

)()()()(

(9)

where terms with A and B refer to 1

and 1

in (7) respectively. For Vmu

)( and

Vm )()( to conform with )( m

u

and )()(

m , the summation over

1k is

continuous and that over 3

k is discrete. 3

k takes three values: n

, 0, n

. The

fields corresponding to 03k are denoted Vm

u))(0(

and Vm ))(0()( , and terms

associated with n

k 3

and n

are merged to form expressions denoted byVmA

nu)(

and VmAn

)()( ; this is made possible by requiring that

)()()(

1

)(

1 n

m

n

m , )()(

)(

1

)(

1 n

m

n

m . (10)

In (10), )()(

1 n

m stands for ),,(

)(

211 n

mkk . We write

VmAVmVm

VmAVmVm

n

nuuu

)())(0()(

)())(0()(

)()()(

(11)

Page 7: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 7

P. N. B. ANONGBA

introducing subsequently the notation Amu

))(0( , AmA

nu)(

, Bmu

))(0( , BmA

nu)(

and

even for the stress. Vmu

))(0( and Vm ))(0(

)( are 3

x independent; VmAnu

)( and

VmAn

)()( are proportional to the sinusoid )(

3xA

n or to its spatial derivative

3/ xA

n . Here also, for points

SP on the interface, V

u

and V)( are

expanded up to terms of first order with respect to 2

x in a similar manner

as in (A.2) (see Appendix A) for u

and

)( . Requiring uu

V and

)()(

V lead to the following equations, writing first the conditions

corresponding to 03k (i.e.

)0()0(

i

V

iuu and

)0()0(

ij

V

ij ).

)0(

1

)0(

1uu

V

0)1()1(

4

1

)1(

11

2

)2(

12

1

)1(

1

2

)2(

1

1

k (a)

2

1

1

1

)1(

11

2

)2(

12

1

)1(

1

2

)2(

1

1

)sgn(

4

)45()45(

k

kibCk

(b)

)0(

2

)0(

2uu

V

2

1

1

1

)1(

1

2

)2(

1

1

)1(

1

2

)2(

1

1

)sgn(

4 k

kibCk

(c)

02

1

)1(

1

2

)2(

1

1

)1(

1

2

)2(

1

1

k (d)

)0(

11

)0(

11

V

0)2(2)2(2)1(

11

)2(

12

)1(

1

)2(

11 k (e)

2

1

1)1(

11

)2(

12

)1(

1

)2(

11

)sgn(6)25()25(

k

kQk

b

(f)

)0(

22

)0(

22

V

0)1(2)1(2)1(

11

)2(

12

)1(

1

)2(

11 k (g)

2

1

1)1(

11

)2(

12

)1(

1

)2(

11

)sgn(2)23()23(

k

kQk

b

(h)

Page 8: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

8 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

)0(

33

)0(

33

V

0)1(

11

)2(

12 (i)

2

1

1)1(

11

)2(

12

)sgn(2

k

kQ

c (j)

)0(

12

)0(

12

V (h) and (e) above (12)

where )1(2/mmm

bC , 4/)(12

CCiQb

, 4/)(1122

CCiQc

;

111/)sgn( kkk ;

m and

m are shear modulus and Poisson's ratio. In equations

(12 a to j) above, )(

1

m and )(

1

m stand for )0,,(

3

)(

211kkk

m and

)0,,(3

)(

211kkk

m , respectively. Other elastic field components are zero. The

conditions corresponding to

nnA

i

VA

iuu and

nnA

ij

VA

ij are now listed as :

nnAVA

uu11

1

)1(

11

2

)2(

1222

1

1

)1(

1

2

)2(

12

1

)1()1(4

n

kk

2/3

22

1

22

112

8n

nn

k

kkbC

(a)

2

2

2

12

2

)2(

1

1

)1(

1

2

)2(

122

1

2

11445

nnkkk

014452

1

2

11

1

)1(

1

nk

(b)

nnAVA

uu22

0

1

)1(

1

2

)2(

1

1

)1(

1

2

)2(

122

1

nk (c)

22

11

22

1

1

)1(

1

2

)2(

1

1

)1(

1

2

)2(

122

1

23

82

n

nn

n

kk

kbCk

(d)

nnAVA

uu33

(c) above and

2/3

22

11

22

1

1

)1(

1

2

)2(

12

8n

nn

kk

kbC

(e)

Page 9: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 9

P. N. B. ANONGBA

nnAVA

1111

)1(

11

)2(

12

22

1

)1(

1

)2(

1

2

1)2()2(2

nkk

2/3

22

1

22

11)43(

n

nnb

k

kkiQ

(f)

)2(

1

2

2

2

12

)1(

1

)2(

1

22

1

2

1)2(2)25(

nnkkk

0)2(2)25()1(

1

2

1

2

11

nk (g)

nnAVA

2222

)1(

11

)2(

12

)1(

1

)2(

1

22

1)1()1(2

nk

22

11

22

1)2(

n

ncbn

kk

QkQi

(h)

0)23()23()1(

11

)2(

12

)1(

1

)2(

1

22

1

nk (i)

nnAVA

3333

)1(

11

)2(

12

22

1

)1(

1

)2(

1

22

nnk

2/3

22

11

422

1

2

12)4(2

n

ncnbccn

kk

QQQkQki

(j)

)2(

1

2

2

2

12

)1(

1

)2(

1

22

1

2)21(2

nnnkk

0)21(2)1(

1

2

1

2

11

nk (k)

nnAVA

1212

)2(

1

2

2

2

12

)1(

1

)2(

1

22

1

2

1)1(2)23(

nnkkk

0)1(2)23()1(

1

2

1

2

11

nk (l)

)2(

1

2

2

2

12

)1(

1

)2(

1

22

1

2

1)1()2(2

nnkkk

22

1

22

11)1(

1

2

1

2

11

)23()1()2(2

n

nnb

n

k

kkiQk

(m)

nnAVA

1313 (l) above and

Page 10: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

10 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

)1(

11

)2(

12

22

1

)1(

1

)2(

1

2

1)1()1(2

nkk

2/3

22

1

22

11)2(

n

nnb

k

kkiQ

(n)

nnAVA

2323

0)1(

1

)2(

1

)1(

1

)2(

1

22

1

nk

(o)

)1(

1

)2(

1

)1(

1

)2(

1

22

12

nk

22

11

22

12)2(

n

ncbcn

kk

QkQQi

(p) (13)

Next, we are concerned with satisfying boundary conditions : (12) leads to the

displacement and stress fields due to an interface straight edge dislocation

( )0,0,(bbII

) parallel to the

3x direction at the origin; the interface is the

31

xOx plane. (13) provides the complementary terms (to first order in n

) in

the elastic fields of an interfacial sinusoidal climb-type edge dislocation.

III - CALCULATION RESULTS

III-1. Displacement and stress fields of an interface straight edge

dislocation

Four distinct couples of values for ),()(

1

)(

1

mm are extracted from (12). These

are (j= a to d) :

)(

13

1

)(

)(

1

m

j

m

jm

k

)(

12

1

1)()(

1

)sgn( m

j

m

j

m

k

k (14)

where

4

)(

CiDmm

a , 0

)(

m

a ;

4

)65()( bmm

b

Q

,

4

3)1(

1)( bmm

b

Q ;

Page 11: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 11

P. N. B. ANONGBA

m

cm

m

c

m

cmm

c

QQQDiC

)89(

22

1

1

22

1

2

11

2)( , m

cmm

c

Q

1)()1(

;

m

c

m

c

m

cmm

d

QQQDiC

3

22

1

1

22

1

2

11

2)( , )()( m

c

m

d (15)

whereij

is the Kronecker delta and )1(2/mmmm

CbD . The couples

),()(

1

)(

1

m

j

m

j , j=a to d, are obtained from (12a to d) associated with the

displacement, (12 e to h) associated with stresses, (12 a, b, i, j) and (12 c, d, i, j), respectively. None of these values satisfies the entire (12). The associated

elastic fields denoted Vm

dau

))(0(

to

and

Vm

da

))(0(

to)( are displayed below. A superposition

of these partial fields will provide the complete form of the solution. We have

at position ),,(321

xxxx

( Vm

j

Vmuu

))(0())(0( , Vm

j

Vm ))(0())(0()()( ; j=a to d):

2

21

)(

2

11

)()(

))(0(

1tan

)1(4)1(

r

xxi

x

xiu

m

m

j

m

m

jm

mm

jVm

j

,

2

2

2

)(

21

)()(

))(0(

2

)1()(ln

)1(

r

xixx

iu

m

m

j

m

A

m

m

j

m

j

m

Vm

j

,

)()()2(2)1(2

212

2)()())(0(

11xx

r

xi

A

m

jm

mm

j

Vm

j

4

2

2

2

12

)()(2

r

xxxim

j

,

)()()1(2)1(2

212

2)()())(0(

22xx

r

xi

A

m

jm

mm

j

Vm

j

4

2

2

2

12

)()(2

r

xxxim

j

,

)()(4)1(

212

2)())(0(

33xx

r

xi

A

m

jm

mVm

j ,

)()()23()1(2

22

1

12

1)()())(0(

12x

r

xJ

r

xi

A

m

jm

m

j

mVm

j

4

2

212

)()sgn(4)1(

r

xxxim

j

m

; (16)

0

1111sin dkxkJ .

Here,iii

xxx /)sgn( , )(1

x is the Dirac delta function andA

has the

Page 12: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

12 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

following definition: 0)(2

xA

when 02x and 1)(

2x

A when 0

2x ;

2

2

2

1

2xxr . Constant terms are omitted in the displacement. The other elastic

fields are zero. We define the elastic fields )())(0(

xum

and )()())(0(

xm

of an

interface straight edge dislocation as

Wmmm

uuu))(0())(0())(0(

Wmmm ))(0())(0())(0()()()(

(17)

with

daj

Vm

j

m

j

Wmuu

to

))(0()())(0(

daj

Vm

j

m

j

Wm

to

))(0()())(0()()( . (18)

Again ))(0( mu

and ))(0()(

m are due to a straight edge )0,0,(bb

II

parallel to

the 3

x direction at the origin in an infinite medium (see [7] for example);

Vm

dau

))(0(

to

and Vm

da

))(0(

to)( are given in (16). )(

to

m

da are real, to be determined by the

condition that the elastic fields satisfy the following relations :

)())(0(

xum

and )()())(0(

xm

are continuous when crossing the 31

xOx plane.

bdum

))(0(

1 for a closed contour in

21xx encircling the dislocation.

Wmu

))(0(vanishes far from the interface (i.e. when

2x ).

It is easy to show that the second condition above correspond to ))(0(

1

mu constant

with m on the interface. All the stresses involved in ))(0(

)(m

and Vm

da

))(0(

to)(

vanish at infinity. Under such conditions, )())(0(

xum

and )()())(0(

xm

correspond

to an interface straight edge dislocation. Next, we express the quantities

involved in the above-mentioned requirements and proceed to satisfy these.

),0,(),0,(321

)2)(0(

1321

)1)(0(

1xxxuxxxu

17

))(0()()()1(4

1eme

m

j

m

j

m

j

m

;

)2)(0(

2

)1)(0(

2uu

27

))(0()()()1(2)12(

1emeiC

j

m

j

m

j

m

mm

m

;

)2)(0(

11

)1)(0(

11

Page 13: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 13

P. N. B. ANONGBA

37

))(0()()()2(2 eme

m

j

m

j

m

j ;

)2)(0(

22

)1)(0(

22

47

))(0()()()1(2 eme

m

j

m

j

m

j ;

)2)(0(

33

)1)(0(

33

57)( eme

m ;

)2)(0(

12

)1)(0(

12

67

))(0()()()23()1(2 emeiC

m

j

m

j

m

j

m

m

(19)

where

)()1(7

))(0()(me

j

m

j

m

j

m .

Here, the subscript j takes the values a to d. The continuity of an elastic field

requires associated i

e constant with m at the crossing of the interface. The

additional condition, ))(0( mu

tends to ))(0( mu

when 2

x , corresponds to

vanishing )())(0(

xuWm

far from the interface. This gives

)())(0(

xuWm

vanishes when 2

x

0/)(7

))(0(

2

m

Wmmieu . (20)

This condition is due to the 2

x component of the displacement )())(0(

xuWm

only; the other 1

x component tends to zero. Because )(7

me is a constant in

medium (m), imposing its value to be identically zero is not mandatory; elastic

displacements, differing only by a constant, are admissible in elasticity.

Instead, we shall choose a value to )(7

me that ensures strongest continuity of

the elastic fields at the crossing of the interface. We have checked that

0)(7

me leads to poor continuity (i.e. only a restricted number of elastic field

components, ))(0( m

iu and

))(0( m

ij , are continuous when crossing the interface). A

best continuity behaviour of the elastic fields at the interface is presented as

follows. The relative volume variation))(0(

)/(m

VV at arbitrary position

),0,(31

xx is obtained to be

Page 14: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

14 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

)0(

131

))(0(

)(2),0,(R

m

iVxxxV

V

(21)

with

),,(21)(21

31

))(0(

27

)0(xxiumeV

Wm

m

m

m

R

.

It has a singularity given by the Dirac delta function )(1

x . We demand )0(

RV to

be constant with m = 1 and 2; this gives a value to )(7

me that is m dependent.

We have

2

1

7

7

21

21

)1(

)2(

e

e (22)

where 12

/ . The expressions for )(1

me and )(6

me in (19)

are merged to read

)()()1(26

)0(

1meVmeiC

Rm

m

m . (23)

We seek continuity of the elastic fields on the interface, hence we impose

)(1

me and )(6

me to be constant with m; this leads, with the help of (23), to

21

1221

6

CCe ,

)0(

21

12

1

2

)(

RV

CCie

. (24)

These expressions are unchanged by inverting the elastic constants. We isolate

j

m

j

m

j

))(0()( with the expression for

1e in (19) and obtain

)0(

12

12))(0()(

21

)23(

2

)(

R

m

mmm

j

m

j

m

jV

CCi

. (25)

Introducing (25) in the expression for )(2

me in (19) and imposing )(2

me to be

constant with m, provide a value to )0(

RV in the form

)1)(1(8

)21)(21(

21

21)0(

ibV

R. (26)

Page 15: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 15

P. N. B. ANONGBA

This relation is unchanged by inverting the elastic constants. The other elastic

parameters are obtained as

)0(

1221

122211

2

))(21)(21(

)21)(1()21)(1(4

RV

ibe

,

)0(

12

12

3

212

)()(

R

m

mmV

CCime

,

)0(

12

12

4

212

)()(

R

m

mmV

CCime

,

)0(

5

21)(

R

m

mmVme

. (27)

The continuities at the interface of ))(0(

1

mu ,

))(0(

2

mu , ))(0(

12

m and ))(0(

)/(m

VV are

achieved. The elastic fields, at position ),,(321

xxxx

, are :

)0(1

2

21

2

11

1

1

21))(0(

1

21

1)1(

2tantan

2R

m

m

m

mmiV

C

r

xx

x

xie

x

xbu

,

)0(

1

1

12

12

21

1

11)1)(0(

2

21

1

4)(ln2ln

2

)21(

RAiV

CCxxr

Cu

)0(

11

1

2

2

2

21

1

2R

iVC

r

x

,

)(2)()()3(

3212

2

4

2

1

2

22))(0(

11miexx

r

x

r

xxxC

Am

m

)0(

4

2

2

2

122

21)1(

)(

R

m

mmiV

r

xxx

,

)(2)()(21

2)1(

)(

4212

2

)0(

4

2

2

2

12))(0(

22miexx

r

xiVC

r

xxx

A

m

Rmm

m

m

,

)0(

212

2

2

2))(0(

334

21)()(2

R

m

mm

Amm

miVxx

r

x

r

xC

,

12

121

22

1

12

1

4

2

2

2

11

1

)1)(0(

12

)()()(

)(

CCx

r

xJ

r

x

r

xxxC

A

)0(

1

1

4

2

21

24

21)sgn(

RiV

r

xxx

,

Page 16: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

16 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

))(0(

33

))(0(

22

))(0(

11

))(0(

)1(2

21mmm

mm

m

m

V

V

m

Rm

RA

iV

r

xxxiVxx

r

x

1

2)1(

)(2)()(

)0(

4

2

2

2

12)0(

212

2

2

2)21(

r

xC

m

mm

. (28)

Corresponding expressions for half-space 2m are obtained by inverting the

elastic constants. The relations between )(mei

and )0(

RV are taken from relations

(21) and (27); the value of )0(

RV is given by (26). Other elastic fields are zero.

Dirac delta function )(1

x is present in ),0,(31

))(0(xx

m

ii (i=1 to 3) and

))(0()/(

mVV , on the interface. The only stress component with a singularity

1/1 x on the interface is

))(0(

12

m .

III-2. Elastic fields of an interface climb-type sinusoidal edge dislocation

Five values for ( )()(

1 n

m , )(

)(

1 n

m ) are extracted from (13); these are

a) )(

122

1

2

22

11

)(

1)(

11

mA

a

n

n

n

m

anm n

kkk

l

, )(

1

)(

10

mA

a

m n ;

b) )(

12

1

2

1

)(

4

2

22

1

)(

3

2

)(

222

11

)(

1)(

1 ~mA

b

nb

m

bn

n

m

bnm

b

n

m

bnm n

k

l

k

ll

kk

l

,

)(

12

1

2

1

1

22

1

1

)(

1

)(

1 ~

~1 mA

b

nb

b

n

m

bn

m n

kkkt

;

c) )(

122

1

2

22

11

)(

1)(

121

mA

c

n

n

m

n

m

cnm n

kkk

l

nA

c

n

bnm

k

kiQ

122

1

1)(

1

2

independent of m;

d) )(

122

1

)(

3

2

)(

222

11

)(

1)(

1

mA

d

n

m

dnm

d

n

m

dnm n

k

ll

kk

l

,

)(

122

1

1)(

1

)(

1

mA

d

n

m

dn

m n

k

kt

;

e)

22

1

)(

4

2

1

2

1

)(

3

2

2

2

1

)(

2

22

1

1

)(

1)(

1

nm

m

e

n

m

e

n

m

e

n

m

enm

rk

l

rk

l

rk

l

k

kl

Page 17: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 17

P. N. B. ANONGBA

)(

12

1

22

1

42 mA

e

c

n

b n

k

Q

k

Q

)(

122

1

22

1

)(

11)(

1

2

mA

e

n

b

nm

m

enm n

k

Q

rk

tki

(29)

where

16/)1(1)(

1bCl

m

mm

a

, )1/(1)1/(1

21

C ,

mmmr /)1(

,

1221 mmm , )21)(1()21)(1(/)1)(1(4

~

1221211

b;

)~

1)(1)(1(4/)1(121

)(

1

1)(

1 b

m

a

mm

bll

,

)~

21)(1)(1(4)1(~

)()~

1(121

1

1211

)(

2 b

m

bb

m

bl

,

bb

mm

bl

121121

1)(

3

~)()

~1)(1)(1(4)1(

,

bb

m

b

m

bl

121121

12

1

)(

4

~)()

~1)(1)(1(8)1(

~

,

)(

11

)(

1)1(

~2

m

bmb

m

blt ;

2/)1()(

1 b

mm

ciQl ;

)1()1(2/)1(2112

)(

1 il

mm

d,

)1()1()1()1(23421122112

)(

2

bmmc

m

dQQl ,

)1()1(2342112

)(

3

bmmc

m

dQQl ,

)(

1

1)(

1)1(2)1(

m

dmc

mm

dlQt

;

4/)1(1)(

1il

mm

e

, )1/()/(

221

)(

2

rQQl

bcm

m

e ,

)1/()/(112

)(

3

rQQl

bcm

m

e , )1/()/5(

)(

4

mbcm

m

erQQl ,

)1/()/1()(

1

mbcm

m

erQQt . (30)

None of these couples satisfies the entire conditions (13). For each couple, we

give in Appendix B the associated oscillating elastic fields BmAAmAVmA

nnn uuu)()()(

and BmAAmAVmAnnn

)()()()()()( defined in (11).

A superposition of these partial fields will provide the complete form of

solution (to first order inn

). The elastic fields )()(

xum

and )()()(

xm

of an

interface sinusoidal edge dislocation may be written as

)())(0()( mAmm nuuu

)())(0()(

)()()(mAmm n . (31)

))(0( m

u

and ))(0()(

m (28) correspond to the fields of a straight edge dislocation

Page 18: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

18 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

lying on a planar interface; )( mAnu

and )(

)(mA

n are oscillating expressions

proportional to either the sinusoid )(3

xAn

or its spatial derivative 3

/ xAn

in

the forms

WmAmAmA

WmAmAmA

nnn

nnn uuu

)()()(

)()()(

)()()(

(32)

with

eaj

VmA

j

mA

j

WmAnnn uu

to

)()()(

eaj

VmA

j

mA

j

WmAnnn

to

)()()()()( . (33)

VmA

ea

nu)(

to

and

VmA

ea

n)(

to)( are given in Appendix B (for )( mA

nu

and )()(

mAn , see [7])

; )(

to

mA

ea

n are real to be determined by the requirement that the elastic fields be

continuous when crossing the interface. It is sufficient to write this condition

for points on the average interface plane. Before displaying the corresponding

equations, we stress what follows.

Both ),0,(31

)(

1xxu

mAn and ),0,(

31

)(

13xx

mAn contain terms with singularity

1/1 x only; the associated coefficients n

Ae

1and n

Ae

8, respectively, have

been taken constant.

),0,(31

)(

2xxu

mAn , ),0,(

31

)(

12xx

mAn and ),0,(

31

)(

23xx

mAn are bounded

functions. Under such conditions, we have considered their linear forms

with respect to 1

x and posed the terms proportional to 1

x constant with

m=1 and 2.

),0,(31

)(

11xx

mAn , ),0,(

31

)(

22xx

mAn and ),0,(

31

)(

33xx

mAn have terms with

singularities 2

1/1 x and

1ln x ; the associated coefficients ( n

Ae

41, n

Ae

51and

nA

e61

) and ( nA

e42

, nA

e52

and nA

e62

), respectively, have been set constant.

),0,(31

)(

3xxu

mAn contains a term with the singularity

1ln x only. The

associated coefficients nA

e3

is taken constant.

We may write :

),0,(),0,(31

)2(

131

)1(

1xxuxxu nn

AA

Page 19: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 19

P. N. B. ANONGBA

)~

1()1(4)1(44)23(1

1

)(

1

)(

2

)(

1

)()(

1

)(

b

m

bm

mm

b

m

b

mA

b

m

a

mA

amm

m

tlllC nn

)1(4)1(4)23(4)(

1

)(

2

)(

1

)()(

1

)(

m

mm

d

m

d

m

d

mA

dm

m

c

mA

ctlll nn

nnA

b

m

em

m

cb

m

e

m

e

m

e

m

e

mA

eeQtiQQllll

1

)(

1

1)(

4

)(

3

)(

2

)(

1

)())(1(2)1(]42[4

;

)2(

2

)1(

2

nnAA

uu

)1~

()()1(22)1(1 2

1

)(

1

)(

4

)(

3

)(

1

)()(

1

)(

b

m

b

m

b

m

b

m

b

mmA

b

m

a

mmA

a

m

tllll nn

)(

1

)(

3

)(

1

1)()1(2

m

d

m

d

m

d

mmA

dtlln

nnA

m

m

ebbm

m

e

m

e

m

e

m

e

mmA

eertQiQrlrlrll

2

)(

1

)(

41

)(

32

)(

2

)(

1

)()(]2[2)1(

;

)2(

3

)1(

3

nnAA

uu

)21(444)21(1 )(

1

)()(

2

)(

1

)()(

1

)(

m

m

c

mA

c

m

b

m

b

mA

b

m

a

mA

amm

m

llllC nnn

nnnA

cb

m

e

m

e

m

e

m

e

mA

e

m

d

m

d

mA

deQQllllll

3

)(

4

)(

3

)(

2

)(

1

)()(

2

)(

1

)(]42[44 ;

)2(

11

)1(

11

nnAA

)~

1)(2(2)1(4431

)(

1

)(

2

)(

1

)()(

1

)(

bm

mm

b

m

b

m

b

mA

b

m

a

mA

amtlllC nn

)2(2)1(412)(

1

)(

2

)(

1

)()(

1

)(

m

mm

d

m

d

m

d

mA

d

m

c

mA

ctlll nn

nnA

b

m

em

m

cb

m

e

m

e

m

e

m

e

mA

eeQtiQQllll

41

)(

1

1)(

4

)(

3

)(

2

)(

1

)())(2()1(]42[4

,

)~

1)(2(2)1()(22

1

)(

1

)(

4

)(

3

)(

2

)(

1

)(

bm

m

b

mm

b

m

b

m

b

m

b

mA

bmtllllC n

)2(2)1()(24)(

1

)(

3

)(

2

)(

1

)()(

1

)(

m

mm

d

m

d

m

d

m

d

mA

d

m

c

mA

ctllll nn

)1()1([21

)(

32

)(

2

)(

1

)( rlrll

m

e

m

e

m

e

mA

e

n

nA

m

m

ebm

m

cbm

m

eertQiQQrl

42

)(

1

1)(

4))(2()1(]44)1(

;

)2(

22

)1(

22

nnAA

)~

1)(1(2)1(441

)(

1

)(

2

)(

1

)()(

1

)(

bm

mm

b

m

b

m

b

mA

b

m

a

mA

amtlllC nn

)1(2)1(44)(

1

)(

2

)(

1

)()(

1

)(

m

mm

d

m

d

m

d

mA

d

m

c

mA

ctlll nn

nnA

b

m

em

m

cb

m

e

m

e

m

e

m

e

mA

eeQtiQQllll

51

)(

1

1)(

4

)(

3

)(

2

)(

1

)())(1()1(]42[4

,

)1~

)(1(2)1()(44)21(2

1

)(

1

)(

4

)(

3

)(

1

)()(

1

)(

bm

m

b

mm

b

m

b

m

b

mA

b

m

a

mA

ammtllllC nn

)1(2)1(4)21(4)(

1

)(

3

)(

1

)()(

1

)(

m

mm

d

m

d

m

d

mA

dm

m

c

mA

ctlll nn

nnA

m

m

ebm

m

bm

m

e

m

e

m

e

m

e

mA

eertQiQrlrlrll

52

)(

1

)(

41

)(

32

)(

2

)(

1

)())(1()1(]2[4

;

Page 20: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

20 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

)2(

33

)1(

33

nnAA

)(

1

)(

1

1)(

1

)(4)

~1()1(4

m

cm

mA

cbm

mm

b

mA

bmmltC nn

nnnA

b

m

em

mmA

em

mm

d

mA

deQtit

61

)(

1

)(1)(

1

)()()1(2)1(4

,

)1~

(2)1(442

1

)(

1

)(

2

)(

1

)()(

1

)(

bm

m

b

mm

b

m

b

mA

b

m

a

mA

amtlllC nn

m

mm

d

m

d

m

d

mA

d

m

c

mA

ctlll nn 2)1(44

1)(

1

)(

2

)(

1

)()(

1

)(

nn

A

m

m

ebm

m

cb

m

e

m

e

m

e

m

e

mA

eertQiQQllll

62

)(

1

)(

4

)(

3

)(

2

)(

1

)()()1(]42[4

;

)2(

12

)1(

12

nnAA

)~

()1(22)1(2/1

1

)(

4

)(

3

)(

1

)()(

1

)(

b

m

b

m

b

m

b

mmA

b

m

a

mmA

allll nn

]~

)23(~

)1(21[2/5

1

2/3

1

)(

1 bmbm

m

bt

nnnAm

e

m

b

mA

e

m

d

m

d

m

d

mmA

deiliQtll

7

)(

1

1)()(

1

)(

3

)(

1

1)(4)1(1)1(2

;

)2(

13

)1(

13

nnAA

)~

1)(1(2)1(441

)(

1

)(

2

)(

1

)()(

1

)(

bm

mm

b

m

b

m

b

mA

b

m

a

mA

amtlllC nn

)1(2)1(44)(

1

)(

2

)(

1

)()(

1

)(

m

mm

d

m

d

m

d

mA

d

m

c

mA

ctlll nn

nnA

b

m

em

m

cb

m

e

m

e

m

e

m

e

mA

eeQtiQQllll

8

)(

1

1)(

4

)(

3

)(

2

)(

1

)())(1()1(]42[4

;

)2(

23

)1(

23

nnAA

)1~

()()1(22)1(2

1

)(

1

)(

4

)(

3

)(

1

)()(

1

)(

b

m

b

m

b

m

b

m

b

mmA

b

m

a

mmA

atllll nn

)(

1

)(

3

)(

1

1)()1(2

m

d

m

d

m

d

mmA

dtlln

nnA

m

m

ebbm

m

e

m

e

m

e

m

e

mmA

eertQiQrlrlrll

9

)(

1

)(

41

)(

32

)(

2

)(

1

)()(]2[2)1(

. (34)

All )( me nA

i are constant with m=1 and 2 (i.e. )2()1( nn

A

i

A

iee ).We seek values

for )(

to

mA

ea

n that provide continuity at the interface for the largest number of the

elastic field components )( mA

i

nu and )( mA

ij

n . We shall proceed in a manner like

that for ))(0( m

iu and

))(0( m

ij in Section 3.1. Restricting ourselves to terms that are

singular, the trace )()(

mA

r

nT of the stress matrix )()(

mAn takes the form

2

)(

2

2

2

0

131

)()()(),0,()(

xmt

x

ImtAxxT

zA

Rn

A

Rn

mA

r

nnn (35)

Page 21: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 21

P. N. B. ANONGBA

With

)(2)()(2

1)(

6151411memememt nnnn

AAAA

R ,

)()()(22

1)(

6252422memememt nnnn

AAAA

R .

The associated oscillating part of the relative volume variation)(

)/(mA

nVV at

position ),0,(31

xx has the same form (35) with similar coefficients

)()1(2

)21()(

11mtmV nn

A

R

mm

mA

R

,

)()1(2

)21()(

22mtmV nn

A

R

mm

mA

R

. (36)

Several relations, interconnecting the )( me nA

i and )(

to

mA

ea

n , are involved in the

procedure under way; these are (by using (34))

)()()1(8

)21()()(

4

)21()(

311411mememememV nnnnn

AA

m

mA

m

A

mm

mA

R

; (a)

)(21

2)(

161mVme nn

A

R

m

mmA

; (b)

)(21

4)()(

14151mVmeme nnn

A

R

m

mAA

; (c)

)2(4)1()()(1)(

851 bc

mmA

e

AAQQimeme nnn

; (d)

)()()()()()()()(

7279mmmemememe

b

mA

be

mA

e

AA

m

AAnnnnnn ,

mmmmcmmmbe

rrrQrrrQi

m /3//32

)(1122212112

,

)~

2)(1)(1(4~

)~

1(2)(2/1

121

2

1

2/1

1

)(

1 bbb

m

bblm

b12121

~4)(32 ; (e)

)(

1

1

11

)(

21)1)(

~1(

~4

2

21)()(

m

b

m

bb

mA

b

m

mA

R

A

RtmVmV nnn

m

m

e

mmA

etin /)1(2

)(

1

1)( ; (f)

Page 22: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

22 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

)(

1

)(

1

)(

1

)(

14)

~1(4)1(

2

21)(

m

c

mA

cb

m

b

mmA

bm

m

mA

RltCmV nnn

)()1(2)1(4)(

1

)()(

1

)(

b

m

e

mmA

e

m

d

mmA

dQtit nn . (g) (37)

We impose the relative volume variation to be continuous at the crossing of the

interface implying that nA

RV

2and1 (36) are constant with m=1 and 2. This provides

values to )(2and1

mt nA

R that are m-dependent. Using (36) and (37 a, b, c) under n

Ae

1

also constant with m, we obtain successively

)(

)1()21()2()21(

2121

4112241211

1

nn

n

AA

A eee ,

)(4

)2()1()21)(21(

2121

14124121

1

nn

n

AA

A

R

eeV ,

nnA

R

mm

mmA

RVmt

1

1122

111222

1

)21()21(

)1()1(2)(

,

nn

A

R

mmm

mmmAVme

1

1122

111222

61

)21()21(1

)1()1(2)(

,

nnn

A

R

mmm

mmAAVmeme

1

1122

111222

4151

)21()21(1

)1()1(4)()(

. (38)

These expressions depend on )1(41

nA

e and )2(41

nA

e ; nA

e1

and nA

RV

1are unchanged by

inverting the elastic constants, as required. The only oscillating stress that has

a singularity 1

/1 x at ),0,(21

xx is nA

13 ; hence, this stress contributes a non-zero

value to the crack extension force when a non-planar interface crack (see Figure 1) is

subjected to general loading (this will be the subject of part III of our study).

Consequently, we demand nA

13 to be continuous at the interface; this requires the

associated coefficient nA

e8

(34) to be constant with m=1 and 2. Inspection of (37 d)

tells us that taking 0)(

mA

e

n leads to )()(518

meme nnAA

, an expression of which is

displayed in (38). Imposing )()(518

meme nnAA

constant opens the possibility to find

a relation between )1(41

nA

e and )2(41

nA

e . In this way, we find

)21()1(

)21()1()1()2(

212121

122112

4141

nn

AAee . (39)

Page 23: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 23

P. N. B. ANONGBA

Further progression comes from (37 e). It tells us that first )()(29

meme nnA

m

A

and second )()(79

meme nnAA

; to see this, it is sufficient to write down three

equations corresponding successively to m=1 and 2, and (third) the one that

results from the inversion of the elastic constants in equation for m=1;

summing, member by member, the two last equations yields )2()2(79

nnAA

ee

and in like manner )1()1(79

nnAA

ee . Furthermore, we work with the value zero

for nA

e , this implies that n

A

b must be zero. A link between n

A

RV

1 and n

A

RV

2

emerges from (37 f). Hence, we write

)()()(279

mememe nnnA

m

AA ,

00)()(

mA

b

mA

e

nn ,

nnA

R

A

RVV

12 . (40)

Under nA

e and n

A

b equal to zero, we have the following relation :

)1(2)1()(4)21/()(2)(

1

)(

3

)(

2

)(

1

)(

1 m

mm

d

m

d

m

d

m

d

mA

dm

A

RmtlllmV nn

)()1(2)(7

1

8meme nn

AmA . (41)

It remains to find values to )1(41

nA

e and )(7

me nA . This can be done by providing

first a value to )( mA

d

n ; for this purpose, we use (37 g) in which 0)(

mA

c

n ( nA

e

and nA

b are equally zero from (40)) and obtain

nnA

R

m

m

m

m

m

mA

dVC

CC1

1

2211

1221)(

21

2)1(

)1(

)1()1(

. (42)

Introducing this value in (41) and imposing )(7

me nA

(as also nA

e8

) to be constant

with m=1 and 2 yields a value to )1(41

nA

e in the form

)(

)()1(

41

41

41n

n

n

A

A

A

eDe

eNue (43)

with

)()1)(1(2)1()21(2)(212121221141

CCQeNuc

An

)1()1()1()1(22111221

CCQb

,

)21()21()1)(1()()(1221212141

c

AQeDe n

Page 24: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

24 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

)21)(1()21)(1()1()1(1222111221

b

Q .

Using (43) and (39), (38) provides values

n

n

n

nA

RA

R

A

RA

RV

VDe

VNuV

2

1

1

1

)(

)( (44)

with

)()1)(1(2)21)(21()(2121211

CCQVNuc

A

R

n

)1()1()1()1(22111221

CCQb

,

)21()21()1)(1(2)(1221211

c

A

RQVDe n

)21)(1()21)(1()1()1(1222111221

b

Q ;

)(

)(

8

8

518n

n

nn

A

A

AA

eDe

eNuee (45)

With

)()1)(1(2)1()21)(21(2)(2121

2

2121218CCQeNu

c

An

)1()1()1()1(22111221

CCQb

,

)21()21()1)(1())(()(12212121218

c

AQeDe n

)21)(1()21)(1()1()1(1222111221

b

Q .

These values are unchanged by inverting the elastic constants, as expected. The

associated nA

e7

and )(2

me nA

are

))(21)(1(

)1()2(

22)(

112212

112

2

22112118

297

CC

CCVemeee

nn

nnn

A

R

A

A

m

AA

)1(4

)21(

))(21)(1(

)1()2(

2

1221

1122

12

221121

221

2

121212

CCC

CCCC

CC

)1(4

)21(

1

2112

CCC. (46)

Beginning with five parameters )(

to

mA

ea

n , only survive )( mA

a

n and )( mA

d

n ; the

others are zero. Using (34), we have

Page 25: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 25

P. N. B. ANONGBA

)(

1

)(

3

)(

1

1)(

7)(

1

)()1(2

2

1)1(

m

d

m

d

m

d

mmA

d

A

m

a

mmA

atlle

l

nnn

. (47)

Here,

)( mA

d

n and nA

e7

are given by (42) and (46). With )( mA

a

n (47) and )( mA

d

n

(42), the elastic fields )( mAnu

and )(

)(mA

n (32) are completely determined, thus

providing the elastic fields )()(

xum

and )()()(

xm

(31) of an interface

sinusoidal climb-type edge dislocation.

IV - DISCUSSION

In the present study, we considered two welded infinitely extended elastic

media S1 and S2 (Figure 2), with an interface S having the form of a corrugated

sheet. We have considered a sinusoidal dislocation running indefinitely on this

surface and have studied the elastic displacement and stress fields ( )()(

xum

and

)()()(

xm

) produced in the surrounding media. The elastic fields are

decomposed individually, in the linear approximation with respect to the

amplitude of the sinusoid, into two terms. The first terms correspond to the

elastic fields ( )())(0(

xum

and )()())(0(

xm

) of a straight dislocation on a flat

interface and the second ones ( )( mAnu

and )(

)(mA

n ) constitute an oscillating

part, proportional to the sinusoid or to its spatial derivative with respect to the

direction where the dislocation runs. We left with an initial vision that the

elastic fields are continuous at the crossing of the interface and join those of a

sinusoidal dislocation in a homogeneous infinite medium, far from the

interface. In Section 3.1, expressions (28) for )())(0(

xum

and )()())(0(

xm

have

been obtained. The result is that in order to ensure the continuity of the elastic

fields at the crossing of the interface, the relative variation of volume at the

interface ))(0(

)/(m

VV exhibits a spatial dependence proportional to the delta

function of Dirac )(1

x , with a coefficient of proportionality )2()0(

RiV (26),

well-defined, dependent on the Poisson ratios and which remains unchanged at

the crossing of the interface. In addition, the following result holds

)1)(1)(21(8

)21)(21(),,(),,(

21

21

31

))(0(

231

))(0(

2

m

mm bxxuxxu . (48)

In other words, under conditions of continuity at the interface, the displacement

component))(0(

2

mu (far from the interface) differs from that of a straight

dislocation ))(0(

2

mu in an infinitely extended homogeneous medium. The

difference observed is constant, well defined, depends on the Poisson ratios of

Page 26: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

26 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

the two media and changes from medium S1 to medium S2. Moreover, this

difference is related to the relative variation of volume at the interface, in the

vicinity of dislocation. The properties which we have just described apply only

when the conditions of continuity are observed. In the contrary case, for

example if 0)0(

RV , the expression of ))(0(

2

mu (28) is not constant with m=1 and

2 on the interface; as a result, ))(0(

2

mu and ))(0(

2

mu meet far from the interface.

The elastic fields )( mAnu

and )(

)(mA

n are completely determined in Section 3.2,

thus providing the elastic fields )()(

xum

and )()()(

xm

of an interface

sinusoidal climb-type edge dislocation. One may wonder if the proposed solution

is the best under condition of continuity of the elastic fields at the interface. The

answer is yes because it is not possible to increase the number of elastic field

components constant with m=1 and 2 at the interface. This is because relations

interconnecting the parameters )( me nA

i exist. The relation (37a) shows that if n

A

RV

1

and nA

e1

are constant with m, then )(41

me nA

and )(3

me nA

will depend on m; similarly,

)(61

me nA

depends on m if nA

RV

1is constant with m, by the relation (37b). It will also

be noted that the relation )()(29

meme nnA

m

A (40) indicates that if n

Ae

9 is constant

with m then )(2

me nA

depends on m. In our study, the constant oscillating elastic

fields with m at the interface are : )(

1

mAnu ,

)()/(

mAnVV ,

)(

22

mAn ,

)(

12

mAn ,

)(

13

mAn

and )(

23

mAn ; the others

)(

2

mAnu ,

)(

3

mAnu ,

)(

11

mAn and

)(

33

mAn are not.

V - CONCLUSION

This study considers two elastic solids S1 and S2, of infinite sizes, firmly

welded along a non-planar interface S having the form of a corrugated sheet

and provides expressions for the elastic fields (displacement and stress) of a

dislocation lying indefinitely on that interface in the sinusoidal direction with

a Burgers vector II

b

(Figure 2) perpendicular to its shape (climb-type

sinusoidal edge dislocation). The proposed solutions ()( m

u

, )(

)(m

: Section 3)

are sums of terms ())(0( m

u

, ))(0(

)(m

) corresponding to a straight interfacial edge

dislocation and ()( mA

nu

, )(

)(mA

n ) proportional to the sinusoid n

A (2) or its

spatial derivative 3

/ xAn

. It is shown that optimum continuity of the elastic

fields at the crossing of the interface is achieved when the relative variation of

volume is continuous at the interface and expressions of the elastic fields are

written under such conditions. The forthcoming work will deal with the crack-

tip stress and the crack extension force when a non-planar crack defined in Section 1 (Figure 1) is loaded in mixed mode I +II +III (work under way, part III).

Page 27: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 27

P. N. B. ANONGBA

REFERENCES

APPENDIX A : DIFFERENCE OF THE VALUES OF )( mu

AND )()(

m

(CLIMB-TYPE EDGE) WHEN CROSSING THE INTERFACE

Our purpose here is to write down the differences u

and

)( (4) on

crossing the interface at arbitrary point ),sin,(3321

xxxxPnnS

. We use the

notation 2

x (3

sin xnn

small) and take the MacLaurin series

expansions of the elastic fields up to terms of first order with respect to ; this

means that

),0,(),0,(),,(31

2

31321xx

x

uxxuxxxu

,

),0,()(

),0,()(),,()(31

2

31321xx

xxxxxx

. (A.1)

)( m

u

and )()(

m are taken from our previous works [7]. We obtain (

iu is the i-

component of vector u

and ij

the ij-element of the stress matrix )( ; i, j= 1 to 3)

n

A

iiiuuxxxu

)0(

321),,(

n

A

ijijijxxx

)0(

321),,(

as

11

)0(

1

11)sgn(8

dkekibC

uxik

,

[1] - P. N. B. ANONGBA, Rev. Ivoir. Sci. Technol., 28 (2016) 24 - 59

[2] - B. A. BILBY and J. D. ESHELBY, In : ‟Fracture”, Ed. Academic Press

(H. Liebowitz), New York, Vol. 1, (1968) 99 - 182

[3] - P. N. B. ANONGBA, Physica Stat. Sol. B, 194 (1996) 443 - 452

[4] - P. N. B. ANONGBA and V. VITEK, Int. J. Fract., 124 (2003) 1 - 15

[5] - P. N. B. ANONGBA, Int. J. Fract., 124 (2003) 17 - 31

[6] - P. N. B. ANONGBA, Rev. Ivoir. Sci. Technol., 14 (2009) 55 - 86

[7] - P. N. B. ANONGBA, Rev. Ivoir. Sci. Technol., 16 (2010) 11 - 50

[8] - P. N. B. ANONGBA, J. BONNEVILLE and A. JOULAIN, Rev. Ivoir.

Sci. Technol., 17 (2011) 37 - 53

[9] - P. N. B. ANONGBA, Rev. Ivoir. Sci. Technol., 26 (2015) 76 - 90

[10] - P. N. B. ANONGBA, Rev. Ivoir. Sci. Technol., 25 (2015) 34 - 55

[11] - P. N. B. ANONGBA, Rev. Ivoir. Sci. Technol., 26 (2015) 36 - 75

Page 28: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

28 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

12/322

1

22

11

1

112

8dke

k

kkibCAu

xik

n

n

n

An

;

1

1

)0(

2

111

8dke

k

bCu

xik

,

122

1

22

1

2

1123

8dke

k

kbCAu

xik

n

n

n

An

;

0)0(

3

u ,

12/322

1

22

1

3

3

112

8dke

k

kbC

x

Au

xik

n

nnAn

;

11

)0(

11

116 dkekiQxik

b

,

12/322

1

22

1

2

1

11

11)43(

2 dke

k

kkAiQ

xik

n

n

nb

An

;

11

)0(

22

112 dkekiQxik

b

,

122

1

22

1

22

112

2 dke

k

QkQiA

xik

n

ncb

n

An

;

11

)0(

33

114 dkekiQxik

c

,

12/322

1

422

1

2

1

33

11

2

2)4(24 dke

k

QQQkQkiA

xik

n

nccbnc

n

An

;

11

)0(

12

11)sgn(2 dkekQxik

b

,

122

1

22

1

112

1123

2 dke

k

kkQA

xik

n

n

bn

An

;

0)0(

13

,

12/322

1

22

1

1

3

13

112

2 dke

k

kkQ

x

A xik

n

n

b

nAn

;

0)0(

23

,

12/122

1

22

1

3

23

112)2(

2 dke

k

QkQQi

x

A xik

n

ncbcnAn

; (A.2)

Page 29: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 29

P. N. B. ANONGBA

where

)]1/(1)1/(1[21

C , 4/)(12

CCiQb

,

4/)(1122

CCiQc

, )1(2/mmm

bC ;

111/)sgn( kkk ;

m and

m are shear modulus and Poisson's ratio.

APPENDIX B : PARTIAL OSCILLATING ELASTIC FIELDS

(CLIMB-TYPE EDGE)

The couple ),()(

3

)(

3

mA

a

mA

a

nn is obtained from (13 a, b, c and e) associated with

the displacement. We have at position ),,(321

xxxx

( VmA

a

VmAnn uu

)()( ,

VmA

a

VmAnn

)()()()( ):

aniiniii

m

m

aVmA

iaI

xA

xx

lu n

1

2

2

1

31

3

32

1

1

)(

1)()(

1

2

0

1

2)1(

n

m

iI ,

2

12

231

4

31

2

0

21

)(

1

)()()()(2

xI

x

IlA

niianiiii

m

an

VmA

iia

n ,

1

2

0

1

)(

1

)(

12)1(2

n

mm

an

VmA

aI

xlAn ,

1

2

021

2

2

1

1

1

)(

1

3

)(

3)1(2

n

m

janj

m

a

nVmA

ajII

xxl

x

An ; (B.1)

122

1

122

1

)1(

11

2

22

1

11

2

22

1

dkezk

edke

zk

e xik

n

xk

xik

n

xk

z

nn

m

,

1

2

11

)1(

0

2112

22

1112

22

1

Kr

xdkeedkeeI

nxikxkxikxknn

m

,

12/3

22

1

12/322

1

)1(

1

11

2

22

1

11

2

22

1

dke

k

edke

k

eI

xik

n

xk

xik

n

xk

a

nn

m

.

Terms in brackets are operators acting on n

A and others, separately; 1

is

the value of z

for z=1, 2

2

2

1

2xxr and subscripts i=1 to 3 and j=1 and 2;

][ xKn

is the nth-order modified Bessel function usually so denoted and ij

is

Page 30: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

30 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

the Kronecker delta. We stress that the various integrations (such as in a

I1

and

z ) performed in the present study are given for spatial positions satisfying

the condition 0)1(2 x

m (i.e. )sgn()1(2

1x

m

) with 1m when

32sin xx

nn (half-space 1) and 2m when

32sin xx

nn (half-space 2).

However, this makes no difference in the elastic fields to first order in n

. The

pair ),()(

3

)(

3

mA

b

mA

b

nn is obtained using (13 a to d) associated with the

displacement. We have (using the similar notations)

b

m

b

m

b

m

bb

a

m

bn

m

m

b

n

AmA

b

bn

lll

xIl

x

lAu

1

~)(

41

)(

4

)(

21

2

1

)(

3

2

1

)(

1)(

1 ~1

)~

1(1

,

b

n

bm

m

m

m

b

n

BmA

b

xx

tAu

1

~11

21

)(

1)(

1

~)1(4)1(

b

bnnbIx

1

~2

1

2

1

2

012

~)1

~( ;

b

n m

bn

m

bn

m

b

m

m

m

bnAmA

bllIl

lAu

1

~)(

4

2

1

)(

3

2

0

)(

2

)(

1)(

2)1(

,

b

n

bnnb

m

m

m

bnBmA

bI

xx

tAu

1

~2

1

2

1

2

01

2

2

1

)(

1)(

2

~)

~1()1(1

;

b

m

b

m

b

m

bb

a

m

bn

m

m

bnAmA

b

bn

lll

xIl

l

x

Au

1

~)(

41

)(

4

)(

21

2

1

)(

3

2

)(

1

3

)(

3 ~1

)~

1(1

,

b

n

bnnb

m

m

bnBmA

bIx

t

x

Au

1

~2

1

2

1

2

012

)(

1

3

)(

3

~)

~1(

;

1

1

)(

4)(

3

)(

2

2

0

)(

2

2

1

)(

3

4)(

1

)(

11 ~1

2

b

m

bm

b

m

bn

m

ba

m

bn

m

bn

AmA

b

lllIl

xIllAn

b

b

b

m

bnl

1

~

1

1

)(

4

2

~1

~

,

b

n

bnnbm

mm

bn

BmA

bI

xtA

1

~2

1

2

1

2

01

2

)(

1

)(

11

~)

~1()2(2)1(2

b

bnnbnbI

xx

1

~3

1

4

1

4

02

1

2

1

2

12

~)

~1()1

~( ;

Page 31: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 31

P. N. B. ANONGBA

b

n m

bn

m

bn

m

b

m

bn

AmA

bllIl

xlA

1

~)(

4

2

1

)(

3

2

0

)(

2

2

)(

1

)(

222

,

b

n

bnnbm

mm

bn

BmA

bI

xtA

1

~2

1

2

1

2

01

2

1)(

1

)(

22

~)

~1()1(2)1(2

b

bnbnbI

x

x1

~2

1

4

02

2

2

1

2

12

~)

~1()

~1( ;

a

m

bn

m

b

m

bb

m

b

b

n

m

bn

AmA

bIllll

xlA

b

n

1

)(

3

2~

)(

41

)(

41

)(

2

21

2)(

1

)(

331

)~

1(~1

12 ,

b

n

bnnbm

m

n

m

bn

BmA

bI

xxtA

1

~2

1

2

1

2

01

2

2

2)(

1

)(

33

~)

~1(2)1(2

;

b

n m

bn

m

bn

m

b

mm

bn

AmA

bllIl

xlA

1

~)(

4

2

1

)(

3

2

0

)(

2

1

)(

1

)(

12)1(2

,

b

n

bmn

m

bn

BmA

b

xtA

1

~11

2

1

)(

1

)(

12

~)1(22

bbnnb

m

mI

xx

1

~2

1

2

1

2

01

2

2

1 ~)

~1()1(23 ;

a

m

bn

b

m

b

m

bb

m

bm

b

nAmA

bIl

lll

xxl

x

Abn

1

)(

3

2

1

~)(

41

)(

41

)(

2

21

)(

1

3

)(

13

1~

)~

1(

21

,

b

n

bnnb

m

b

nBmA

bIx

xt

x

A

1

~2

1

2

1

2

012

1

)(

1

3

)(

13

~)

~1(2

bbm

m

x 1

~11

2

1 ~)1(2)1( ;

b

n m

bn

m

bn

m

b

mm

b

nAmA

bllIll

x

A

1

~)(

4

2

1

)(

3

2

0

)(

2

)(

1

3

)(

23)1(2

,

b

n

bnnb

mm

b

nBmA

bI

xxt

x

A

1

~2

1

2

1

2

01

2

2

1)(

1

3

)(

23

~)

~1()1(12

; (B.2)

The couple ),()(

1

)(

1

mA

c

mA

c

nn is obtained using (13 f, g, l and m) associated with

stresses. We obtain

Page 32: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

32 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

1

2

1

2

1

)(

1)(

1)21(

xI

x

lAu

man

m

m

c

n

AmA

c

n

,

01

2

21

21

)(

1)1(4)1(

2Ix

xx

iQAu

nm

m

m

b

n

BmA

c

n

;

1

2

0

)(

1)(

2)21()1(

nm

m

m

m

c

n

AmA

cI

lAu n

,

01

2

2

2

1)(

2)1(1

2I

xx

iQAu

n

m

m

b

n

BmA

c

n

;

1

2

1

2

)(

1

3

)(

3)21(

xI

l

x

Au

man

m

m

cnAmA

c

n

,

01

2

2

3

)(

3

2Ix

iQ

x

Au

n

m

bnBmA

c

n

;

01

2

2

1

4)(

1

)(

11)21()1(22 I

xIlA

mnman

m

cn

AmA

c

n ,

01

2

2

)(

11)2(2)1( I

xiQA

nm

m

bn

BmA

c

n

1

2

0

2

02

1

2

2 nnII

xx ;

01

2

2

)(

1

)(

22)21(2 I

xlA

mn

m

cn

AmA

c

n

,

02

1

2

21

2

0

2

)(

22)1(2)1( I

xxI

xiQA

nm

m

bn

BmA

c

n ;

1

2

1

22)(

1

)(

33)21(2

xIlA

mann

m

cn

AmA

c

n ,

1

2

0

2

1

2

2)(

332)1(

nm

m

nbn

BmA

cI

xxiQAn ;

1

2

0

1

)(

1

)(

12)21()1(2

nm

mm

cn

AmA

cI

xlAn ,

Page 33: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 33

P. N. B. ANONGBA

1

2

0

2

2

1

1

2

1

)(

12)1(23)1(2

n

m

mmnbn

BmA

cI

xx

xiQAn ;

anm

m

c

nAmA

cI

xxl

x

An

1

2

2

1

1

)(

1

3

)(

13)21(2 ,

1

2

02

2

1

13

)(

13)1(2)1(

nm

m

b

nBmA

cIx

xxiQ

x

An ;

1

2

0

)(

1

3

)(

23)21()1(2

nm

mm

c

nAmA

cIl

x

An ,

1

2

0

2

2

1

3

)(

23)1(1

n

m

b

nBmA

cI

xxiQ

x

An ; (B.3)

The pair ),()(

1

)(

1

mA

d

mA

d

nn is calculated from (13 h, i and o, p) associated with

stresses. We have

a

m

dn

m

d

m

m

d

n

AmA

dIl

xl

x

lAu n

1

)(

3

2

2

1)(

2

1

)(

1)(

1

,

1

2

02

2

11

1

)(

1)(

1)1(4)1(

nm

m

m

m

d

n

BmA

dIx

xx

tAu n

;

1

)(

3

2

0

)(

2

)(

1)(

2)1(

m

dn

m

d

m

m

m

d

n

AmA

dlIl

lAu n

,

1

2

0

2

2

1

)(

1)(

2)1(1

n

m

m

m

d

n

BmA

dI

xx

tAu n

;

a

m

dn

m

d

m

m

dnAmA

dIl

xl

l

x

Au n

1

)(

3

2

2

1)(

2

)(

1

3

)(

3

,

1

2

02

)(

1

3

)(

3

n

m

m

dnBmA

dIx

t

x

Au n

;

a

m

dn

m

d

m

dn

m

d

m

dn

AmA

dIlllIl

xlAn

1

)(

3

4

1

)(

3

)(

2

2

0

)(

2

2

)(

1

)(

11)(2 ,

1

4

02

1

2

2

21

2

0

2

)(

1

)(

11)2(2)1(2

nnnm

mm

dn

BmA

dI

xxI

xtAn ;

Page 34: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

34 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

1

)(

3

2

0

)(

2

2

)(

1

)(

222

m

dn

m

d

m

dn

AmA

dlIl

xlAn ,

2

1

0

2

21

2

0

2

1)(

1

)(

22)1(2)1(2

x

IxI

xtA

nm

mm

dn

BmA

d

n ;

a

m

dn

m

dn

m

dn

AmA

dIl

xllAn

1

)(

3

2

2

1)(

2

2)(

1

)(

332 ,

1

2

0

2

1

2

2)(

1

)(

332)1(2

nm

m

n

m

dn

BmA

dI

xxtAn ;

1

)(

3

2

0

)(

2

1

)(

1

)(

12)1(2

m

dn

m

d

mm

dn

AmA

dlIl

xlAn ,

1

2

0

2

2

1

1

2

1

)(

1

)(

12)1(23)1(22

n

m

mmn

m

dn

BmA

dI

xx

xtAn ;

a

m

dn

m

d

m

d

nAmA

dIl

xl

xl

x

An

1

)(

3

2

2

1)(

2

1

)(

1

3

)(

132 ,

1

2

02

2

11

1

)(

1

3

)(

13)1(2)1(2

nm

mm

d

nBmA

dIx

xxt

x

An ;

1

)(

3

2

0

)(

2

)(

1

3

)(

23)1(2

m

dn

m

d

mm

d

nAmA

dlIll

x

An ,

1

2

0

2

2

1)(

1

3

)(

23)1(12

n

mm

d

nBmA

dI

xxt

x

An ; (B.4)

The couple ),()(

3

)(

3

mA

e

mA

e

nn is obtained from (13 j, k, and n, l ) associated with

stresses. We have (here, we write m

r for

mr , m=1 and 2)

2

)(

)(

4

2

)(

1

1

)(

3

2

)(

2

2

)(

2

1

)(

1)(

1

111

12

xr

rl

xr

rl

xr

rl

x

lAu

mnr

m

m

m

er

m

er

m

e

m

m

e

n

AmA

e

abncb

m

m

e

m

e

m

eIQ

xQQ

r

l

r

l

r

l

1

2

2

1

)(

4

1

)(

3

2

)(

2242

111 ,

)(

2

1

2

2)(

1

1

)(

1)1)(1(4

2m

n

r

m

mmn

m

e

m

nBmA

e

xxrt

x

iAu

Page 35: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 35

P. N. B. ANONGBA

1

2

2

2)(

20

)(

12)1)(1(4)(

xxtIQtx

m

mn

m

eb

m

e ;

)(

)(

4)(1

)(

3)(2

)(

21

2

)(

1)(

212

2)1(m

n

rm

m

er

m

er

m

ebn

m

m

m

enAmA

erlrlrlQ

lAu

0

)(

4

)(

3

)(

242 IQQlll

cb

m

e

m

e

m

e ,

1)(

)(

1

2

0

)(

1

2

2

1)(

2)()1(1

2

brm

m

enb

m

e

m

m

nBmA

eQrtIQt

xx

iAu

m

n

;

2

)(

)(

4

2

)(

1

1

)(

3

2

)(

2

2

)(

2

)(

1

3

)(

3

111

12

xr

rl

xr

rl

xr

rll

x

Au

mnr

m

m

m

er

m

er

m

e

m

m

enAmA

e

abncb

m

m

e

m

e

m

eIQ

xQQ

r

l

r

l

r

l

1

2

2

1

)(

4

1

)(

3

2

)(

2242

111 ,

1)(

)(

1

2

0

)(

12

3

)(

3)(

2

brm

m

enb

m

e

m

nBmA

eQrtIQtx

i

x

Au

m

n

;

2

)(

2)(

4

2

)(

1

2

1

)(

3

2

)(

2

2

2

)(

22)(

1

)(

11

1112

12

xr

rl

xr

rl

xr

rllA

mnr

m

m

m

er

m

er

m

e

n

m

en

AmA

e

abnb

m

m

m

e

m

e

m

e

nIQ

xQ

r

rl

r

rl

r

rl

1

4

2

1

)(

4

1

1

)(

3

2

2

)(

2222

111

1

2

0

2

)(

4

)(

3

)(

242

ncb

m

e

m

e

m

eI

xQQlll ,

2

1

2

2

2

1)(

11)2(2)1(

xx

xiA

m

m

n

BmA

e

n

1)(

)(

1

2

0

)(

1)(

brm

m

enb

m

eQrtIQt

m

;

)(

)(

4)(1

)(

3)(2

)(

21

2

2

)(

1

)(

2212

22m

n

rm

m

er

m

er

m

ebn

m

en

AmA

erlrlrlQ

xlA

0

)(

4

)(

3

)(

242 IQQlll

cb

m

e

m

e

m

e ,

2

2

2

2

2

)(

22)1(2)1(

x

xx

iAm

m

n

BmA

e

n

1)(

)(

1

2

0

)(

1)(

brm

m

enb

m

eQrtIQt

m

;

Page 36: NON-PLANAR INTERFACE CRACK UNDER GENERAL LOADING II. … · Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36 3 P. N. B. ANONGBA f x x h h n n n n n ¦ [ N G N { [ 3 3 sin cos (1) where

36 Rev. Ivoir. Sci. Technol., 30 (2017) 1 - 36

P. N. B. ANONGBA

2

)(

)(

4

2

)(

1

1

)(

3

2

)(

2

2

)(

22)(

1

)(

33

1112

12

xr

rl

xr

rl

xr

rllA

mnr

m

m

m

er

m

er

m

e

n

m

en

AmA

e

abncb

m

m

e

m

e

m

eIQ

xQQ

r

l

r

l

r

l

1

2

2

1

)(

4

1

)(

3

2

)(

2242

111 ,

2

2

2

1)(

332)1(

nm

m

n

BmA

ex

xiAn

1)(

)(

1

2

0

)(

1)(

brm

m

enb

m

eQrtIQt

m

;

)(

)(

4)(1

)(

3)(2

)(

21

2

1

)(

1

)(

1212

2)1(2m

n

rm

m

er

m

er

m

ebn

mm

en

AmA

erlrlrlQ

xlA

0

)(

4

)(

3

)(

242 IQQlll

cb

m

e

m

e

m

e ,

2

1

21)(

)(

1

2

1

)(

12)1(23)1(2

xxQt

xiA

m

mbr

m

emnn

BmA

em

n

1)(

)(

1

2

0

)(

1)(

brm

m

enb

m

eQrtIQt

m

;

2

)(

)(

4

2

)(

1

1

)(

3

2

)(

2

2

)(

2

1

)(

1

3

)(

13

1112

12

xr

rl

xr

rl

xr

rl

xl

x

Amn

r

m

m

m

er

m

er

m

em

e

nAmA

e

abncb

m

m

e

m

e

m

eIQ

xQQ

r

l

r

l

r

l

1

2

2

1

)(

4

1

)(

3

2

)(

2242

111 ,

1)(

)(

1

213

)(

13)1(2)1(

br

m

em

mnBmA

eQt

xxi

x

A

m

n

1)(

)(

1

2

0

)(

12)(

brm

m

enb

m

eQrtIQtx

m

;

)(

)(

4)(1

)(

3)(2

)(

21

2)(

1

1

)(

2312

2)1(2m

n

rm

m

er

m

er

m

ebn

mm

e

nAmA

erlrlrlQl

x

A

0

)(

4

)(

3

)(

242 IQQlll

cb

m

e

m

e

m

e ,

1)(

)(

1

2

0

)(

1

2

2

3

)(

23)(1)1(

brm

m

enb

m

e

mnBmA

eQrtIQt

xxi

x

A

m

n ; (B.5)

122

1

)(

11

2

22

1

dkezk

e xik

n

xk

z

n

.