Issue 43

F. Majid et alii, Frattura ed Integrità Strutturale, 43 (2018) 79-89; DOI: 10.3221/IGF-ESIS.43.05

   * P

P

(

)



r

max



1

    ( ) D

P P P

 ; 0,



u a u

 c P P  max ; u

       



1

 c





   * P

P

*

r

max





1

P P P

u a u

 

 

 

 ( )

  , c

D

;

(8)

Pa



1

    D





 ( ) 1;



,1

Pa

    

So:

    ( * P

P

P

)

   D

 ; 0,



r

max

max

 ( )

 c

;

u

 P P max a

 

 c





    * P

P

P

*



r

max

max



 

 

 ( )

  , c

 

D

(9)

;

Pa

 P P max a

 

  

 

 ( ) 1;



D

,1

  

Pa

So:



P

*

   D

 ; 0,



r

 ( )

 c

;

u

 P P P P   max max a

 

 c







P

*

*



r

max



 

 

 ( )

  , c

 

D

(10)

;

Pa

 P P max a

  





 ( ) 1; ( ),1 P 

D

a

  

In addition:

P P



 ( )   D

 ; 0,

   ; c

a r



:

  

  

 c







 

 

*

  







 ( )

  , c

D

(11)

;

Pa

  

  





 ( ) 1;



D

,1

Pa

  

86