Residual ultimate strength of large opening box girder with pitting corrosion damage under torsion and bending loads

In this paper, the residual ultimate strength of large opening box girder with pitting corrosion under combined loads is investigated by ABAQUS software. A primary investigation was first conducted to compare the influences of corrosion types. Afterwards, effects of some studied parameters including the depth, density, volume, and location of the pit, which may affect the ultimate strength, were analyzed based on a series of FE results. It was concluded that the relative corroded volume loss has a non-negligible effect on the residual ultimate strength. For torsion and sagging cases, the side plates' pits significantly reduce the ultimate strength. For the hogging case, the effect of bottom plate pitting on the ultimate strength should be paid attention to. The interaction relationship between torsion and bending moment was analyzed. An interaction equation is proposed for evaluating the ultimate strength of large opening box girders with pitting damage under combined loads.