The effects of bonding clearance and interference fit on the strength of adhesively bonded cylindrical components

Experimental Analysis of Static and Fatigue Strength Properties in Press-Fitted and Adhesively Bonded Steel–Aluminium Components

“…2. In light of this, ε θ can be related to p C by applying the thick walled cylindrical theory reported in equation (4), and well demonstrated by Croccolo et al [26].…”

“…These tests allow evaluating the mean strength of the purely anaerobic adhesive (τ ad ), without the interference contribution. The clearance value (difference between diameters) was realised in the range 0.02-0.05 mm since this value is associated with the maximum strength for SHJ, as showed by Sekercioglu et al [4]. Specimens were cleaned with Loctite 7061, which is a general purpose cleaner for preparing surfaces to be bonded with adhesive, then, specimens were cured for 24 h at 40 • C. All tested specimens showed an adhesion failure, like that reported in Fig.…”

“…1) is able to provide the range U min-max =0.013−0.037 mm. The actual coupling pressure p C was evaluated according to equation (4). Finally, the axial static friction coefficient μ A was calculated by applying equation (6), in which F int is given by the load cell of the hydraulic press at the initial release (movement) of the specimens, and the coupling surface A is equal to 1,257 mm 2 .…”

“…Results are reported in Table 3. A comparison between slip-fitted steel-steel joints [4] and slip-fitted aluminium-steel joints is reported in Fig. 6.…”

“…As a matter of fact, dry press-fitted couplings achieve only 20-30% of nominal surface contact (metal to metal), whereas the adhesive presence is able to fill the voids (air), reaching 100% of contact area [1]. However, the strength of HJ must be evaluated accurately, since it is affected by various factors, such as the coupling pressure [2], the type and the way of assembling [3,4], the type of materials in contact [5,6], the surface roughness [7], the curing type and the curing methodology [8], the operating temperature [9] and the loading type [10]. Most of literature about HJs is mainly focused on steel-steel components (Steel Hybrid Joints -SHJs) [2-5, 11, 12] and on their verification technique (non-destructive testing) [13,14].…”