Issue 48

M. Bezzerrouki et alii, Frattura ed Integrità Strutturale, 48 (2019) 491-502; DOI: 10.3221/IGF-ESIS.48.47 493 ADEKIT A-140 Adhesive presents a high mechanical performance and is used in several industrial sectors, in aeronautics. Among these advantages:  Excellent mechanical and thermal performances up to 100°C  Excellent strength to dynamic loads (vibrations and impacts)  Product adapted to stringent ageing and aggressive environments The mechanical properties of the various substrates are taken from the tensile curves of aluminum plates and mass specimens of adhesive Adekit A-140 which are represented in Fig. 2, [16]. (a) (b) Figure 2 : S tress/strain curves: a) Aluminum plate 2024-T3; b) Adhesive Adekit A-140 [16]. Materials E: Young Modulus (GPa) G: Shear modulus (GPa)  : Poisson coefficient Aluminum: 2024-T3 69 36.92 0.3 Adhesive: Adekit A-140 2.690 0.99 0.3 Table 1 : Elastic properties of the Aluminum plate and the adhesive [16]. The adhesive bonded joints have several advantages compared to the mechanical assemblies (riveting and bolting) which ensures uniform stress distribution and transfer over the bonded surface following the absence of holes and avoids overweight bolts but it is necessary to prevent the stress concentration at the edge and the environment effects (temperature, moisture) which causes a degradation of their mechanical properties and which will consequently have a bad transfer of load and thus a disband. For our study, we tried to present a method for the bonding of the aluminum plates on the damaged surface; this method consists to remove a material from the aluminum plate over overlap area with a thickness of 0.2 mm on a single plate, which illustrated at assembly named: Model 2, as shown in the Fig. 3. And the second modification is to remove a thickness of 0.1mm of aluminum material from each plate which represented at assembly called: Model 3, as shown in the Fig. 4. This procedure covers the adhesive layer which can protect the assembly from the aging following the effect of temperature and moisture. Figure 3: Model 2: ASTM D1002 modified (reduction of 0.2 mm for one plate) 0.2 mm L o 2 mm 2 mm 0.2 mm Overlap area Overlap area.