Issue 50

F. Larbi Chaht et alii, Frattura ed Integrità Strutturale, 50 (2019) 331-341; DOI: 10.3221/IGF-ESIS.50.28 334 The elastic and carbon resistance properties of the epoxy are chosen from the library of the CADEC [19] which determines, according to the volume fraction, the properties of the carbon / epoxy composite, and which allows us to calculate the resistance parameters by changing the thickness. Figure 1: Geometrical modification of the composite plate E1 = 170000MPa ν12 = 0.342 G12 = 4800MPa XT =2050 YT=62 E2 = 9000MPa ν13 = 0.342 G13 = 4800MPa XC=1200 YC=190 E3 = 9000MPa ν23 = 0.342 G23 = 4500MPa SL =81 ST=81 Table 1 : For a 65% fraction and 0.25mm thickness [20]. E1 = 195000MPa ν12 = 0.32 G12 = 8167MPa XT = 2500 YT=74 E2 = 13450MPa ν13 = 0.32 G13 = 8167MPa XC= 1500 YC=224 E3 = 13450MPa ν23 = 0.32 G23 = 7137MPa SL =90 ST=90 Table 2 : For a 75% fraction and a 0.2mm thickness. E1 = 221500MPa ν12 = 0.31 G12 = 13540MPa XT = 3000 YT=82 E2 = 21670MPa ν13 = 0.31 G13 = 13540MPa XC= 2200 YC=236 E3 = 21670MPa ν23 = 0.31 G23 = 11790MPa SL = 97 ST=97 Table 3 :For a fraction of 85% and thickness of 0.125mm. E: Young’s modulus, ν: Poisson’s ratio, G: shear modulus XT: Longitudinal tensile strength, XC: Longitudinal compressive strength, YT: Transverse tensile strength YC: Transverse compressive strength, SL: Longitudinal shear strength, ST: Transverse shear strength Different ply orientations of the composite adherent are considered in this study to investigate their effect on the failure load. The value of θ (orientation angle) is taken from the longitudinal direction of the structure (x-axis) and varied from 0◦ to 90◦ (Table 1,2,3) with step of 15◦. Then, in the second case, some modifications were introduced and presented in Fig.8. All layers have the same matrix (epoxy) and the same fiber materials (carbon).