Tensile, bending and shear strength distributions of adhesive-bonded butt joint specimens

Adhesive bonding is becoming one of the popular joining techniques in metal industries since it offers different options over other techniques such as welding and diffusion bonding. Any dissimilar metals are easily adhesive-bonded together. In this study, experiments were carried out in order to provide the statistical data with strength evaluation methods: tensile, shear and four-point bending tests for thermosetting epoxy resin based adhesive-bonded butt joints. The certification of the probability in the adhesive strength that shows the tendency of brittle fracture is studied. The effect of the adhesive sectional area on the adhesive strength is evaluated. For the tensile and shear tests, the strength distributions of 5 × 6 mm2 sectional area specimens show higher probability than the 2 × 3, 3 × 4 and 4 × 5 mm2 area specimens, and Weibull modulus of 5 × 6 mm2, m = 4.049 and 4.412 for the tensile and shear tests respectively. For the four-point bending test, 3 × 4 mm2 specimens have the highest probability value than others. And the shear test is less affected by sectional area comparing with other test methods. The adhesive bonding strength distribution between 304 stainless steels with thermosetting adhesives shows the highest probability in four-point bending test. The strength testing methods that have higher probability of strength are four-point bending, shear and tensile tests in order.