Issue 22

S. Bennati et alii, Frattura ed Integrità Strutturale, 22 (2012) 39-55; DOI: 10.3221/IGF-ESIS.22.06

0  w and 

u w respectively mark the beginning of interface softening

the instants such displacement exceeds the values

and debonding behaviour.

a)

b)

c) Figure 10 : Relative displacement  w ( z ) and tangential stress  ( z ): a) stage 1:

0 M M  ; b) stage 2:

0.9  u M M ; c) stage 3:

1.01  u M M .

Fig. 11 shows a plot of the bending moment in the beam, M , as a function of the abscissa, z , for four values of the applied couple, M , corresponding to the four stages of behaviour described in the previous section. Note that with increasing M and the consequent progressive detachment of the reinforcement, the strengthened beam’s response tends towards that of a beam lacking any reinforcement.

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