Numerical Simulation of Bi-Adhesive Lap Joints

The stresses in single-lap bonded joints are highest at the edges, where failure frequently originates, and lowest at the center. The stress concentration at the ends of a bonded lap joint is influenced by the relative stiffness of the adherend and adhesive used. The stress concentration is smaller and the joint strength may be increased the less stiff the adhesive used in the bond line for a particular adherend. With this technique, high joint strength can be attained. Adhesive joints have been used in a lot of investigations in the past. Numerous industries, including the automotive and aerospace sectors, conduct in-depth studies to ascertain how adhesive joints affect lap bonding. It has also been discovered that when bi-adhesive is utilized in a lap joint rather than mono adhesive, more uniform stress can be obtained. Bi-adhesive was applied with a firm adhesive in the overlap's center and a low-modulus adhesive at its edges, which were expected to undergo stress concentrations. A concentrated force was delivered to one side of the entire portion, which had one side fixed. The result shows that the stiffer adherend has higher strength. Through finite element modeling, the rise in apparent lap-shear strength was qualitatively predicted.