# Effect of CFRP on Buckling Performance of Thin-Walled Cylindrical Steel Tanks with Dents and Corrosion

## TL;DR

This study shows that carbon fiber reinforcement can significantly improve the buckling resistance of thin steel tanks damaged by dents and corrosion.

## Contribution

The novel contribution is demonstrating CFRP's effectiveness in restoring structural stability of corroded and dented thin-walled steel shells under external pressure.

## Key findings

- Corrosion and dents significantly reduced buckling capacity and structural stability of thin-walled steel shells.
- CFRP strengthening improved ultimate load, ductility, and postbuckling behavior in damaged specimens.
- SEM analysis revealed progressive corrosion from localized pitting to widespread delamination.

## Abstract

Thin-walled steel cylindrical shells offer excellent
strength-to-weight
ratios but are highly sensitive to mechanical imperfections and corrosion-induced
degradation. This study investigated the effects of dents and corrosion
on the buckling behavior of 0.45 mm-thick thin-walled cylindrical
steel shells, as well as the efficiency of carbon fiber-reinforced
polymer (CFRP) strengthening under external pressure. Nine specimens
were tested, including corroded samples exposed to 2.5% and 5% HCl
solutions to simulate material deterioration. The results revealed
that both corrosion and dents significantly reduced the buckling capacity
and structural stability of the specimens. However, in comparison
with earlier investigations on unstrengthened and partially strengthened
specimens, the external CFRP layers substantially mitigated capacity
losses, improving ultimate load, ductility, and postbuckling behavior.
Complementary SEM analysis provided microstructural insight into the
corrosion mechanism, illustrating the progressive surface degradation
from localized pitting to widespread delamination at higher corrosion
levels. Overall, CFRP confinement was confirmed as a highly effective
retrofitting solution for restoring strength and stability in imperfect
and corroded thin-walled steel shells.