Displacement Behavior of Single-lap Joints Made from Functionally Graded Polymeric Materials

For adhesively bonded joint security and long-term use of the joint, a precise stress analysis must be performed on single-lap joints. A single-lap joint, formed by joining two layers at a given lap length, is the most widely used adhesive joint type in practice. Nowadays, it is stated that the mechanical properties and joint strength can be increased by adding clay and graphite to the polymeric material used in single-lap joints, trying to estimate the joint strength for various loading conditions. This paper focuses on the bending moment behavior of a single-lap joint composed of newly designed functionally graded polymeric materials (FGPMs). For this purpose, the single-lap joint geometry subject to a bending moment is discussed. However, it is assumed that the bonded beams in the connection are composed of FGPMs. The beams are modeled using a new recently developed FGPMs. FGPMs forming the glued beams was obtained by adding PAM 96/98 and PV 60/65 graphite powders in epoxy resin at 3%, 6%, 9% and 12% volume ratios. The effects of graphite type and graphite volume ratio on maximum displacements were investigated in the joint subjected to bending moment. In addition, peeling stress (σy), Shear stress (τxy) and also von-Mises stress (σvon) occurring in the mid-plane of adhesive layer with PAM 96/98 and PV 60/65 graphite powder added were determined for each volume ratio and presented in graphs.