Bolted–bonded hybrid joints for complex connections beyond lap joints

This is the authors' abstract. We don't add key points for this paper.

Preloaded bolted-bonded hybrid joints have commonly been characterised using lap-joint specimens loaded predominantly in axial shear. However, many structural connections show complex shear, in which eccentricity and rotation induce additional torsional shear stresses. In this study, a preloaded hybrid joint in complex shear on hot-dip galvanised steel was investigated to extend experimental evidence beyond lap-joint typologies. A slip-resistant bolted reference without adhesive and hybrid configurations using two different epoxy adhesives were examined. Bolt edge distance ( e = 15, 25, 35 mm) and outer splice-plate thickness ( t o = 10, 15, 20 mm at e = 15 mm) were varied, and the response was characterised using both machine displacement and DIC-based relative displacement. Across all configurations, a consistent staged response was observed, comprising an initially steep rise, a stiffness transition, attainment of a peak load Fmax, a first pronounced load drop, and a sustained post-drop branch. Hybridisation increased Fmax substantially relative to the friction-only reference, ranging from about +50% at e = 15 mm to about +110% at e = 35 mm for Sikadur 370 (with Scotch-Weld 7240 showing smaller but consistent gains). Edge distance reduced peak resistance for all concepts, but the reduction was substantially stronger for the friction-only reference than for the hybrids, indicating a mitigation of rotation-driven localisation by hybridisation. Overall, adhesive selection was shown to influence not only load capacity but also the kinematic pathway into the post-drop regime, and the dataset was intended to serve as a benchmark for subsequent modelling.