The literature states that the existing guidelines mainly focus on the ultimate strength of uniform corroded joints in the Jacket-type re-assessment. However, joints are non-uniformly corroded in different shapes in reality. Results derived from theoretical equations in these scenarios are significantly different from the actual capacity of the frame joints. This paper studies the influences of thickness and corroded area on the T- joint’s ultimate strength for a chord based on the numerical model ABAQUS. Numerical results show the effects of location and dimension at corroded areas on the tubular joint ultimate strength. Moreover, this research proposes a new formula based on API to estimate the strength of T-joints connected with non-uniform corroded compressive braces in certain conditions. This equation is validated by comparison of the numerical simulation in independent cases.

This paper presents a construction method regarding a tubular nano-mesh for which the anodic oxidation of aluminum (Al) wire is used. The first step of tubular-nano-mesh production is Al-wire anodization. A new anodizing device was made for the wire-based uniform anodization for this study, and a high-purity (99.999%) Al wire with a 2 mm diameter was used. Also, an electrolytic solution was used as a 0.07 M oxalic acid, while the electrolytic-solution temperature was maintained at -3℃. While the applied voltage and the process time were varied, the AAO (Anodic Aluminum Oxide) characteristics of the Al wire were observed. When 60 V was applied to the wire, alumina cracks were not evident, whereas the application of 100 V produced alumina cracks; this is because the growth rate of the nano-pore voltage affected the alumina shape. For the subsequent construction of the tubular alumina structure, an Al-etchant (HCl + H2O + CuCl2 + 2H2O) etched-Al portion of the anodized wire was employed. The final step is a pore-widening process that is implemented through the hole channel. The anodized wire was dipped in the alumina etchant, and the pore-wall removal was checked over time.