Analysis of Mixed Adhesive Bonded Joints Part II: Parametric Study

Mixed adhesive joints for low and high temperature applications have been studied in the past in numerical terms. However, for parametric studies and for design purposes, it is easier to work with an analytical model than with the more sophisticated finite element method. A model was developed for mixed adhesive single lap joints and for mixed adhesive double lap joints. The theoretical formulation of this model is presented in a preceding paper (Part I). The adhesive shear and peel stress distributions obtained by the analytical model were compared with a finite element analysis and very close agreement over the entire overlap length was obtained. In the present paper, the analytical model was used to assess the effect of the temperature varying continuously from low to high temperatures for a mixed adhesive single lap joint and for a mixed adhesive double lap joint with titanium adherends. To study a general case that contemplates any combinations of adhesives, the temperature variation was considered in terms of the low temperature adhesive Young's modulus/high temperature adhesive Young's modulus ratio, keeping constant the adherends Young's modulus. A low ratio corresponds to a high temperature and a high ratio corresponds to a low temperature. Other parameters such as the overlaps of the low and high temperature adhesives and the effect of the high temperature adhesive modulus were also investigated.