Experimental and numerical assessment of tensile loaded tubular adhesive joints

Adhesive bonding is extensively used by several industries. A large number of joint architectures are available, of which the most typical ones are single-lap, double-lap and scarf joints, each one with their own benefits and limitations. Bonded joints are also widely used to join tubular components in the pipeline industry (petroleum production, energy and wastewater treatment), in vehicle frames (aeroplanes, cars and buses), in civil engineering truss structures and in space structures. This joint design is mainly subjected either to axial or torsional loads. For the design process of these joints, analytical or numerical predictive techniques can be used. This work performs a comprehensive experimental and numerical study of axially loaded tubular joints between aluminium adherends and bonded with three different adhesives. The effect of the overlap length between inner and outer tubes (L-O) was addressed in the experiments and numerical study. A conventional continuum-based finite element method analysis was undertaken to analyse peel (sigma) and shear stresses (tau) in the adhesive layer. Cohesive zone models were subsequently employed to perform a damage evolution analysis and to predict the joint strength. A comparison between axisymmetric two-dimensional and full three-dimensional simulations was undertaken. The cohesive zone model technique was positively validated for the strength analysis of tubular joints. It was also shown that the joints' geometry and type of adhesive highly influenced the joints' behaviour.