Mechanical Behavior of Corroded Aluminum Tanks Repaired with Composite Patches: A Numerical Investigation and Experimental Stiffness Validation

To enhance the structural durability of degraded metallic assets, this study investigates an advanced repair strategy for corroded aluminum tanks using composite patches. An epoxy matrix reinforced with four distinct fiber types high-performance synthetic (carbon, boron, glass) and eco-friendly natural (flax) is evaluated to balance mechanical restoration with environmental sustainability. The methodology relies on a combined numerical-experimental validation framework. Finite element analysis (FEA) is conducted via ABAQUS to comprehensively map Von Mises stress distributions within the repaired zone as a function of defect length, internal pressure, and three distinct defect orientations (longitudinal, transverse, and circumferential). In parallel, experimental tensile testing of repaired specimens is performed to assess the global mechanical response of the structure and to validate the effectiveness of the composite patching strategy under service-like loading conditions. The results reveal that corrosion orientation critically governs repair efficiency. Carbon/epoxy patches applied over circumferential defects yield the highest mechanical resilience, successfully restoring structural integrity. While the bio-based flax/epoxy patches exhibit lower absolute strength than their synthetic counterparts, they deliver substantial structural reinforcement. Ultimately, this validated framework provides a powerful tool to optimize composite patch repairs, paving the way for reliable, sustainable, and eco-friendly maintenance in industrial pressure vessel applications.