Geometrical and material optimization of tensile loaded tubular adhesive joints using cohesive zone modelling

Abstract

ABSTRACTBonding with adhesives is increasingly being used in the design of mechanical structures, because of the significant advantages of this technique compared to traditional joints. Different joint configurations are available, depending on the desired bond strength to be achieved and geometry of the parent structures. Tubular joints find applications in the piping industry, vehicle frames or thin-walled tubes, for instance, but they are seldom studied in the literature. This work numerically compares the performance of three structural adhesives on the tensile strength of aluminium tubular joints, after validation of the numerical tool with experiments. The numerical analysis consisted of using the Finite Element (FE) method to analyse peel (σy) and shear stresses (τxy) in the adhesive layer and cohesive zone models (CZM) to predict the maximum load (Pm). Numerically, the effect of the overlap length (LO) and the thickness of the inner and outer tubes (tSI and tSE, respectively) is addressed. Additionally, outer and inner chamfering of the tubes was tested to reduce peak stresses and increase Pm. The CZM technique was positively validated for the strength analysis of tubular joints. It was also shown that the joints’ geometry and type of adhesive highly influence the joints’ behaviour.