Issue 31

H.F.S.G. Pereira et alii, Frattura ed Integrità Strutturale, 31 (2015) 54-66; DOI: 10.3221/IGF-ESIS.31.05 60 ultimate slip obtained during pullout was almost 5 mm and 1000 mm, Fig. 9 and 10, respectively. In Fig. 10 it was opted to depict only the load - slip relationship up to a slip of 1 mm, nevertheless the pullout load kept constant practically up to the ultimate displacement (1000 mm). In both simulations, and excluding Mesh 1, the maximum pullout load was reached approximately for a slip of 0.2 mm, and the value was of 63.9 and 66.3 kN for the simulations carried out with and without bond stress degradation with slip, i.e. with an ultimate local slip of 5 and 1000 mm, respectively. Considering no degradation of the bond, stress increased in nearby 5% de maximum pullout load. Figure 9 : Pullout load - slip relationship with a 5 mm displacement at failure. Figure 10 : Pullout load - slip relationship with a 1000 mm displacement at failure. After carrying out the simulations considering an elastic behaviour of the concrete surrounding the rebar, it was assessed the influence of the mesh refinement when using the Concrete Damage Plasticity model to model the surrounding concrete behaviour. For this purpose, three meshes were used, in particular, Mesh 3 and 4 that were the same used in the simulations when considering an elastic behaviour for concrete, and another mesh with a higher refinement in the rebar zone and a coarser refinement in the concrete farther from the interface zone. Regarding the interface cohesive behaviour, the adopted damage evolution also was of the type displacement with linear softening and maximum degradation. The value of displacement at failure was 5 mm. Tab. 6 includes the number of nodes and elements, as well as the computational time for completing the simulation of the pullout test. Mesh Element quantity Nodes quantity Computational Time 3 4100 5100 3h 36min 4 21960 25010 51h 40min 5 20500 24580 29h 46min Table 6 : Mesh parameters.