Issue 52

H. Ghahramanzadeh Asl et alii, Frattura ed Integrità Strutturale, 52 (2020) 9-24; DOI: 10.3221/IGF-ESIS.52.02 21 For comparison of shear stresses, which is an essential mechanical property for SLJs, there was a dramatic decrease for AA compared to SS joints. While there is no significant difference between failure loads of these joints, there was almost 37% increase in shear stress in reference to AA joints. Lowest deformation in Y direction occurred at SS joints and this increased shear stress in adhesive. FEA Results AA FEA Results SS FEA Results AS Failure Load (kN) Displacement (mm) Failure Load (kN) Displacement (mm) Failure Load (kN) Displacement (mm) 1 mm/min 18.952 0.92 17.295 0.52 18.464 0.73 10 mm/min 19.359 0.87 20.038 0.62 19.206 0.73 25 mm/min 21.110 0.99 21.608 0.78 20.423 0.79 50 mm/min 22.250 1.22 22.503 1.193 20.639 0.89 Table 4: FEA failure loads and X-directional deformation values Figure 15: Peel and Shear Stress in adhesive values C ONCLUSION n this study, aluminum, steel, and aluminum-steel SLJs were bonded by using DP460NS epoxy adhesive and tested at different displacement rates. Joints surfaces and thickness were optimized to achieve the highest failure loads. Results are given as follows: 1. In order to determine the effect of surface roughness, different surface roughness was examined using AFM. Failure loads were not affected surface roughness’s lower than 200 nm. 2. Before tensile testing of adhesive joints under different displacement rates, three different adhesive thickness were investigated. Optimum adhesive thickness was determined as 0.13 mm. I