Response of Perforated Tubular Members Repaired With CFRP to Bending Moment

Abstract In corrosive environments, like the ocean, offshore steel tubular structures operate for long periods without proper protection. Therefore, they are susceptible to perforation damage as consequence of concentrated corrosion, which compromises their structural integrity and increases the risk of progressive collapse. As an alternative to traditional hot-works, composite laminates are being considered for strengthening perforated steel tubular members. However, there is a lack of research on the structural capacity recovered for composite laminate repair for given damage dimensions and geometrical characteristics of tubular members subjected to bending loads. Studying the repair performance on structures subjected to bending loads is relevant because tubular members in offshore units constantly experience combinations of loads. Depending on the structure’s slenderness and damage extension, the bending moment may represent the dimensioning load for repair sizing. This study proposes to experimentally repair and test, under bending load, 1:3 scale samples of flare-boom offshore tubular structures with perforation damage using carbon fiber composite laminates. The responses from experiments and numerical models are compared to investigate strengthening performance and define a suitable patch size through a simplified parametric expression. The results indicate that simulated samples, whose repair was sized by the proposed expression, recovered the bending moment capacity, suggesting the feasibility of the repair and dimensioning procedure.