Issue 59

T. Cuong-Le et alii, Frattura ed Integrità Strutturale, 59 (2022) 232-242; DOI: 10.3221/IGF-ESIS.59.17

   

   

3

  

  

 t

( ) 1 w

w

w



2 c c w w

 3 2 c

 

 

c

e

1 c e (1 )

(5)

1

f

w

w

tm

c

c

where   1 2 3, 6.93 c c and wc is the critical crack opening which can be considered as the fracture crack opening given in Eqn. (6).

G f

 5.14 F

w

(6)

c

tm

Based on the curve of stress-crack opening relationship, it can be obtained a new curve having the feature of stress-strain through Eqn. (7). Thus, the strain  t at tensile strength  tm can be evaluated from crack opening. Where eq l can consider as a length of element (meshed size). After this assumption, the stress-strain curve relationship given in Fig. 3.

w

    t tm

(7)

l

eq

Figure 3: Behavior in tension.

Compressive damage and tension damaged component Compression damage variable ( dc ) This parameter is used to specify compressive stiffness degradation damage, c d is determined through plastic strain  pl c and a using a constant factor c b with 0 < c b ≤ 1.



1



E

1/ 1 c c b

  1

d

(8)





c



pl

1

 c



 

c c E

c

 0.7 c b to evaluate the parameter c d . Fig. 4 illustrates the relationship between compressive

In this paper, assumption

 35 cm f calculated in Eqn. (8).

damage parameter and inelastic strain with concrete having strength

235