PSI - Issue 47

Francesco Ascione et al. / Procedia Structural Integrity 47 (2023) 460–468 Author name / Structural Integrity Procedia 00 (2019) 000–000

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meaning that only the displacement jump in the rebar direction (i.e. the slip) is considered as an active degree of freedom of the zero-thickness steel/concrete interface element.

Fig. 2. Schematic representation of the steel/concrete interaction: (a) bond-layer model; (b) adopted bond-slip relation taken from the CEB-FIP Model Code (CEB-FIP, 2013).

3. Numerical results In this Section, the proposed model has been first validated by performing a double lap shear test (Section 3.1) and then adopted to simulate the mechanical behavior of a nano-enhanced FRP-plated RC beam. Suitable comparisons with experimental works have been carried out to demonstrate the effectiveness and reliability of the proposed model to analyze such kinds of nano-enhanced structures. 3.1. Validation of the proposed model A concrete prism bonded with an FRP sheet and subjected to a double lap shear test, analyzed by (Irshidat and Al Saleh, 2016), is simulated for validating the proposed model. The geometry and boundary conditions of the test are reported in Fig. 3a. Concrete and steel with Young’s modulus of 30 GPa and 300 GPa, respectively, have been used. The Poisson’s ratio has been set at 0.25 for both materials. The reinforcement system is made of a 1 mm thick FRP sheet having a tensile E-modulus of 230 GPa.

a

b

Mesh 1

Mesh 2

Mesh 3

P

Steel support

100

100

FRP sheet

100 25

nano-enhanced epoxy

150

25

Cohesive elements

Fig. 3. The double lap shear test: (a) geometric and boundary conditions of the tested specimens; (b) computational discretizations employed for the mesh sensitivity analysis.