Issue 51

A. Chiozzi et alii, Frattura ed Integrità Strutturale, 51 (2020) 9-23; DOI: 10.3221/IGF-ESIS.51.02 19 Case study Masonry material parameters Masonry/FR P bond strength (f b ) [MPa] Compressive strength (f k ) [MPa] Tensile strength (f t ) [MPa] Shear strength (f vk0 ) [MPa] SB01, SB02 [25,51,52] 8.00 0.32 0.32 0.30 Table 1: Material parameters. Every node position is controlled by two parameters, with the exception of one-parameter edge-nodes and the four fixed vertex-nodes. Thus, also relying on the symmetry of the problem, the optimization problem is governed by fourteen parameters, which can be reduced to nine for to symmetry. A collapse load  2.69 p kN/m 2 has been coputed for the unreinforced case. Fig. 8(a) and Fig. 8(b) respectively depict the computed failure mechanism obtained by means of the proposed GA-NURBS approach and the homogenized FE limit analysis technique proposed in [25]. Moreover, a good agreement can be found when comparing the obtained results from the proposed GA-NURBS approach with the outcomes of both original experiments and different numerical procedures found in the literature [27]. In particular, it can be seen that the proposed GA-NURBS approach slightly overestimates the actual collapse load. Figure 8: SB01 masonry panel without openings tested in [51]. (a-c) Unreinforced and reinforced case, respectively: collapse mechanism with the GA-NURBS approach; (b-d) Unreinforced and reinforced case, respectively: collapse mechanism with the homogenized FE limit analysis proposed in [25].