<p>In this study, finite element and frame structure analyses were conducted to evaluate the effect of re-corrosion of thickness-reduced steel plates repaired using patch plates. In the analyses, some elements of the analytical model were eliminated to simulate re-corrosion under dead load. Based on the results of the finite element and frame structure analyses, the shared axial forces of the main and patch plates during re-corrosion were evaluated. It was found that even for re-corrosion of a thickness-reduced steel plate repaired by patch plates, frame structure analysis can be used to evaluate shared axial forces. In addition, cases of re-corrosion with eccentricity were evaluated in this study. Finally, it was shown that a part of the dead load induced in the thickness-reduced plate was redistributed to the patch plates, and the change in the dead load during the redistribution could be estimated by frame structure analysis.</p>