Experimental Study on the Effect of Bonding Area Dimensions on the Mechanical Behavior of Composite Single-Lap Joint with Epoxy and Polyurethane Adhesives

The effects of joint geometry parameters, such as adherend thickness (1.76, 3.52 mm), width (10, 20, 30 and overlap length 20 on the behavior single-lap joints (SLJs) under tensile loading are investigated in this study. Peak force, stiffness, shear stress, normal stress properties. SLJs manufactured with carbon fiber composite adherends two different types adhesives, polyurethane epoxy, which present a flexible rigid mechanical response. results showed that increasing all 3 geometric parameters (L, W, T) leads to significant increase load capacity (on average, 88.4, 101.5, 16.9%, respectively). For epoxy joints, these increases were 47.7, 100, 46%, respectively. According results, W is parameter most influence joints. However, it was observed an has no effect adhesive substrate’s stresses. Epoxy behave approximately elastically until failure, while SLJ load-displacement curves include initial linear elastic part followed by more ductile before failure. Joint stiffness affected for both types, except length, led negligible Moreover, damage surfaces analyzed internal stresses (shear peel) assessed using analytical model Bigwood Crocombe.