Issue 48

J.P.S.M.B. Ribeiro et alii, Frattura ed Integrità Strutturale, 48 (2019) 332-347; DOI: 10.3221/IGF-ESIS.48.32 336 Property AV138 2015 7752 Young’s modulus, E [GPa] 4.89±0.81 1.85±0.21 0.49±0.09 Poisson’s ratio,  0.35 a 0.33 a 0.30 a Tensile yield stress,  y [MPa] 36.49±2.47 12.63±0.61 3.24±0.48 Tensile strength,  f [MPa] 39.45±3.18 21.63±1.61 11.48±0.25 Tensile failure strain,  f [%] 1.21±0.10 4.77±0.15 19.18±1.40 Shear modulus, G [GPa] 1.81 b 0.70 b 0.19 b Shear yield stress,  y [MPa] 25.1±0.33 14.6±1.3 5.16±1.14 Shear strength,  f [MPa] 30.2±0.40 17.9±1.8 10.17±0.64 Shear failure strain,  f [%] 7.8±0.7 43.9±3.4 54.82±6.38 Toughness in tension, G IC [N/mm] 0.20 c 0.43±0.02 2.36±0.17 Toughness in shear, G IIC [N/mm] 0.38 c 4.70±0.34 5.41±0.47 a manufacturer’s data b estimated from the Hooke’s law using E and  c estimated in reference [26] Table 3: Mechanical and fracture properties of the adhesives Araldite ® AV138, Araldite ® 2015 and Sikaforce ® 7752 [26-28]. Joint dimensions, fabrication and testing Fig. 2 illustrates the dimensions and geometry of DCB, ENF and SLB specimens, whereas Fig. 3 represents the geometry and dimensions of the SLJ and DLJ. Figure 2: Geometry and dimensions of the DCB (a) , ENF (b) and SLB specimens (c) . The specimens’ dimensions were as follows next (in mm): total length or mid-span L =180 (SLJ and DLJ), L =140 (DCB) or L =100 mm (ENF and SLB), initial crack length a 0 ≈40 mm (DCB) or a 0 ≈60 mm (ENF and SLB), adherends’ thickness h =3, adhesive thickness t A =0.2, joints’ width B =25 and overlap length L O =12.5, 25, 37.5 and 50 (SLJ and DLJ only). In the present work, the DLJ were fabricated with equal h in the middle and outside adherends, which is not consistent with the