Closed-form solutions and stress analysis of stainless steel/aluminum hybrid joint

Abstract

Hybrid joints are a combination of adhesive bonding and mechanical fastening that are able to combine the advantages of both joint types. Today, hybrid joining is attractive in automotive applications as the technique can offer various benefits during manufacturing. A 3 mm thin plate of Aluminium A7075 and stainless steel 304 were used as the adherend material for experimental test and the adhesive used was high performance Araldite Epoxy adhesive. This research examines stainless steel/aluminium hybrid joints to be tested in two ways. First is by using ANSYS software application where it was employed to deal with stress analysis of the adhesive bonding of hybrid dissimilar joints using the finite element method. Hybrid dissimilar joint specimens were fabricated having five bond thicknesses; t (i.e., 0.4 mm, 0.8 mm, 1.2 mm, 1.6 mm and 2.0 mm). The effect of bond thickness was investigated by using the commercial finite element package in ANSYS. Various thicknesses of adhesive give different values of maximum von Mises stress. It is found that greater thickness results in higher maximum stress. Moreover, various thicknesses of adhesive also result in different values of deformation. This shows that more deformation occurs when the thickness of adhesive is increased. This analysis proves that increasing adhesive thickness reduces the joint strength, mainly because stress distribution is increased on adhesive surfaces. Before proceed to second approach, comparison between experiment and ANSYS was done. The purpose for this comparison is to prove that ANSYS analysis is similar with experiment and the result can be use. The second approach is to formulate a new equation using MATLAB tools for analysis of shear stress distribution along the bond line under effect of adherend thickness ratio and adherend Young’s modulus ratio. The solution is formulated based on the analysis of Paroissien Eric. The least stress intensities in the joint could be achieved with a suitable ratio of thickness and Young’s modulus of adherends. Result from both method ANSYS and analytical model were compared and the results were in agreement, which means that the analytical model can be used at least for the configuration considered in this study.