Issue 53

Y. Saadallah, Frattura ed Integrità Strutturale, 53(2020) 417-425; DOI: 10.3221/IGF-ESIS.53.32



  /





  /



  

e 

f 



e 

d   



d 



f 

F

D

/ e e E    ;

;

(1)

f

f

Axial section

Tangential section

Radial section

Figure 1: Scanning electron micrographs of the three sections of cork [5].

Figure 2: Test set-up and cork specimen.

where E, F, D are respectively the slopes of the three different domains. e  , f  , d  and e  . ,,  d represent respectively the stresses and strains at the boundaries of each of the three domains. So, we write the behavior model as follows:

  

E

  





      

e

   E F F E E F    

  

 



 e

 

.

(2)

 

e

f

 F D

  

  

  

  

D

D

  





 

 f



 f

 

e

d

EF

F

419