Issue 61

K. Belkaid et alii, Frattura ed Integrità Strutturale, 61(2022) 372-393; DOI: 10.3221/IGF-ESIS.61.25





4

2 2 C C c s C s 

4

2 2   

11 C C c 11

12

66

22

  2 2 4 4   C C C C c s C c s 4 (   

)

12

11

22

66

12





 





2

2 2

2 C s cs 22

16 C C c 11 

 

  c

2 C C s

12

66





4

2 2 C C c s C c 

4

2 2   

22 C C s 11

12

66

22









4

2 2

4 C c cs 22 )

26 C C s 11 

 

  s

12 66 2 ( C C c

  2 2 2 2   C C C C c s C c s 4 (   

)

66

11

22

12

66

2

2

44 44 55   C C c C s   45 55 44   C C C cs

2

2

55 55 44   C C c C s



  s



c

cos ,

sin

and  is angle between global axis and local axis for each laminate layer.

where



E

12 2 E

E

1

2







C

C

C

;

;

;

66 12 55   C G C G C G 13 44 ; ; 

11

12

22

23

 

 

 







1

1

1

12 21

12 21

12 21

Figure 1: Geometry and coordinate system of the sandwich plate

The differential equilibrium equations for transverse stress analysis are given as follows [2]:

     k xy

   

k

n h







k

xx



 

dz

 

xz





x

y

h



k

1



k

1

  k

k

   

  

 

n h



xy

yy

k



 

 

dz

(4)

yz





x

y

h



k

1



k

1

376