PSI - Issue 64

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Nicola Nisticò et al. / Procedia Structural Integrity 64 (2024) 2238–2245 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Figure 11. Concrete cube specimen. (a) Model construction: Particle random placement; (b) Voronoi and (c) Delunay geometrical models; (d) observed damage; (e) numerical results. (Fascetti et al., 2018)

3.2. Microplane model applications The applications presented here are based on the model (Fig. 7) proposed in Ožbolt et al. (2001) implemented in the software MASA ( Ožbolt, 1988) . Initially, this model was applied (Gambarelli et al., 2016b) to capture the effect of confinement (Fig. 12) in concrete specimens wrapped by Carbon Fiber Reinforced Polymers (CFRP). Subsequently (Gambarelli et al., 2016c), it was used (Fig. 13) to model concrete specimens, at the mesoscale, as bi-phase composite materials, combining a random aggregate structure with mortar, modeled using a microplane approach . In both cases, the numerical results were compared against experimental data reported in Wang et al. (2008). Additionally, Nisticò et al. (2016) investigated the effect of CFRP reinforcement in reinforced concrete beams, comparing (Fig. 14) the numerical results with experimental data reported in (Bocciarelli et al., 1996).

Fig. 12. CFRP wrapped concrete specimen. Numerical vs experimental results. (a) Stress-strain relationship; (b) Typical failure; (c) numerical modeling (Gambarelli et al., 2016b).

Fig. 13. Concrete specimen: Mesoscale approach. (a) Numerical vs experimental results: stress-strain relationship; (b) FEM modeling; (c) results of the numerical simulation (Gambarelli et al., 2016c).

Fig. 14. (a) Load-displacement curves: comparison between the experimental one (thin line) and the numerical curve (thick line) obtained using either linear or nonlinear contact Elements (b) numerical predication of crack propagation at 15 and 40 mm (Nisticò et al., 2016).