Minimization of Peeling Stress in an Adhesively Single-lap Joint Using the Bees Algorithm

In the present research work, the reduction of peel stress in the adhesively bonded single-lap joints has been studied. The distributions of normal and shear stresses generated in the adhesive joint were obtained using the two-dimensional elasticity theory, as well as the stress-strain and strain-displacement relationships. Minimization of the peel stress was performed using the bees algorithm, during which the process variables included the adhesive and adherends thicknesses.  The composite joint was loaded by a tensile force while the adherends and adhesive layers were considered to behave as isotropic materials with linear elastic properties. The results showed that based on an optimum thickness ratio of 2.54, the magnitude of the peel stress can be reduced by 36%. As Young's moduli ratio, and consequently, the asymmetric adhesion bonding increased, the maximum amount of peeling stress decreased. Also, the increase in Young's modulus of the bottom layer led to the disruption of stress distribution at the interface of the softer adherend (top layer) and the adhesive layer, while this effect was almost absent at the other interface.