Issue 52

H. Ghahramanzadeh Asl et alii, Frattura ed Integrità Strutturale, 52 (2020) 9-24; DOI: 10.3221/IGF-ESIS.52.02 15 Figure 5 shows the boundary conditions of the analysis. The model was only allowed to displace through x-direction till failure. Stresses were derived from point A which is on the center top of the adhesive layer as shown in Fig. 6. Figure 5: Boundary conditions of single lap joint Figure 6: Critical points in the adhesive layer R ESULTS AND DISCUSSIONS Determining joint surface and adhesive thickness ifferent SS and AA surface quality were investigated. Results have been given in Fig. 7 for aluminum specimens. According to these results, from 600-grit to 1200-grit, there was an increase but from 1200-grit to 4000-grit there was not a significant improvement at failure loads. Also, for 4000-grit surface, results from samples had more fluctuation than 1200-grit surface. For this reason, 1200- grit SiC paper was employed for aluminum specimens. Figure 7: Failure load, a) Effect of the grit size b) Effect of adhesive thickness D