Issue 29

L. Contrafatto et alii, Frattura ed Integrità Strutturale, 29 (2014) 196-208; DOI: 10.3221/IGF-ESIS.29.17 205 assumed, on the basis of the experimental evidence. The cubic function in Fig. 15, depending only on two constitutive parameters, was selected. 0 1 2 3 4 5 DISPLACEMENT [mm] 0 10 20 30 40 PULL-OUT FORCE [kN] Experimental Mohr-Coulomb SDA Figure 14 : SDA simulation by code FracSDA8 of test B-10-3. Pull-out force and stress distribution at the peak load. 2 3 0 0 0 0 0 5 4.5 1.4 0 1.9 t t t t t t t t du du du f f if du du du du du f if du du                                       Figure 15 : Bond slip model. Interface stress versus shear slip. Table 3 reports the parameters value assumed in the calculations. The predictions were once again accurate, both in the estimation of the pull-out strength and in the prediction of the failure mechanism. For example, in Fig. 16 the results concerning test B-14-10 are reported. The maximum value of parameters in Table 3 were used. The steel bar rupture and the corresponding anchor strength are correctly reproduced, as it can be observed by the comparison between pictures 16 and 5. Initial Tangent Stiffness 5 f t /  d u 0 [N/mm 3 ] Constant 1.9 f t [N/mm 2 ] Shear Slip d u 0 [mm] Basalt 50000 35 ÷ 50 0.1 ÷ 1 Limestone 20000 15 0.1 ÷ 1 Sandstone 11000 2 ÷ 5 0.1 ÷ 1 Table 3 : Bond slip model parameters 0 5 du f t