Investigation on failure mechanism of stiffened plates with pitting corrosion under uniaxial compression

摘要

The uniaxial compressive behavior of stiffened plates with pitting corrosion is investigated, with a specific concern about corrosion-caused transition within different failure modes. To control the geometrical parameters and distributions of corrosion pits, ten specimens with mechanically-drilled cylindrical corrosion pits near the weld seams are deliberately prepared and tested. During the test, the effects of these influential factors on the complete axial load vs. response curves and failure mechanism are studied. To develop a conceptualized model for physically addressing the coupled load-corrosion effect on the failure modes of stiffened plates, some necessary numerical simulations are supplemented. From the test and simulation results, corrosion can cause a significant variation in the redistribution of internal forces among the constituent components of the stiffened plates. If corrosion-induced damage in the stiffener and plate is comparable, a stiffened plate would experience a transition between plate buckling and eventual stiffener tripping. The proposed conceptualized model that consists of several segments with connecting rotational springs is capable of describing the controlling failure mechanisms of stiffened plates under various corrosion scenarios. On this basis, for the purpose of the identification of the failure modes of pitting corroded steel stiffened plates, a relative cross section loss factor is proposed and validated by a large number of the tested and simulated cases.