PSI - Issue 47

Umberto De Maio et al. / Procedia Structural Integrity 47 (2023) 469–477 Author name / Structural Integrity Procedia 00 (2019) 000–000

473

5

adhesive (see Fig. 2). The plate and the adhesive have Young’s modulus of 235 GPa and 1 GPa, respectively, while the tensile strength of the CFRP sheet is 4200 MPa. From the computational point of view, three different kinds of discretization procedures have been used. In particular, three-node triangular bulk elements arranged in a Deaulanay tessellation and 1D two-node truss elements have been used for the concrete and steel rebars, respectively. Moreover, a mapped mesh has been employed for the reinforcement system, adhesive included. Cohesive elements are placed along the boundaries of the finite element mesh in the concrete phase and along the concrete/FRP interface. The parameters of the traction-separation law required by the cohesive elements are given in Table 1. It is important to note that, the mode II fracture parameters are not available in the experimental results taken as reference (Hamad et al., 2015), and they are set following the calibration procedures reported in (De Maio et al., 2019b).

Fig. 2. Geometry, set-up, and boundary conditions of the FRP-plated RC beam.

Table 1. Parameters required by the cohesive traction-separation law.

0 n K [N/m 3 ]

0 s K [N/m 3 ]

c n t [MPa]

c s t [MPa]

I c G [N/m]

II c G [N/m]



1.3162e14

1.3162e14

2.1

4.2

150

1500

225

Quasi-static simulations under plane stress assumption have been performed on a control RC beam (beam without FRP plate) and a FRP-plated RC beam, reporting the obtained numerical results, in terms of load-deflection curve, in Fig.3.

70

L12

B

60

L11

L10

A

50

C

40

L9

L8

30

L7

Load [kN]

L6

20

L5

L4

L3

L2

Control beam Loading path FRP-plated beam Unloading path FRP-plated beam

10

L1

0

0

5

10

15

20

25

30

35

40

45

Deflection [mm]

Fig. 3. Load-deflection curves of the control and FRP-plated RC beams with the performed unloading paths.