Static strength prediction of curved composite joints under internal pressure

Nowadays, adhesive joints are largely applied in the automotive, aircraft and aerospace, civil, and naval industries. Although several applications involve flat (plane) adherends, curved joints play an important role in many engineering applications like civil and aircraft construction. This work aims to investigate three structural adhesives, ranging from brittle to ductile, applied in curved joggle-lap joints between carbon fibre reinforced polymer adherends and subjected to internal pressure, to validate a robust design procedure and provide project guidelines for this complex structural, geometrical, and loading system, which constitute the main novelty of the proposed work. A numerical cohesive zone model parametric analysis was undertaken by varying the overlap length, thickness of the adherends, and adherends' curvature, including the evaluation of peel and shear stresses in the adhesive, failure mode comparison, maximum load, and energy dissipated after failure. Validation of the cohesive zone model technique was initially performed using flat single-lap joint under tensile loads. A significant effect of the overlap length and thickness of the adherends on the maximum load was found, while the adherends' curvature effect on the maximum load was negligible. Ductile adhesives, although less strong, generally performed better in terms of maximum load and dissipated energy.

Automated summary

This work investigates the use of three structural adhesives with different properties in curved joggle-lap joints. The study validates a robust design procedure and provides project guidelines for the complex structural, geometrical, and loading system. A numerical cohesive zone model analysis examines the effects of overlap length, adherends' thickness, and adherends' curvature on the load-bearing capacity, failure mode, and energy dissipation. Ductile adhesives generally outperform brittle ones in terms of maximum load and energy dissipation.