Advanced numerical modelling for predicting residual compressive strength of corroded stiffened plates

An advanced methodology for predicting the residual compressive strength of corroded stiffened plates is developed here using the non-linear finite element method. The non-uniform loss of a plate thickness is accounted for on a macro-scale. In contrast, mechanical properties are changed using the constitutive model to reflect the corrosion degradation impact on a micro-scale. Three different stiffened plate thicknesses are considered, and ultimate compressive capacity is analysed for different severity of corrosion degradation. First, the deterministic analysis is performed, and numerical results are validated against the experiment. Then, the corrosion fields are modelled with the use of random fields. Different statistical characteristics of the generated random fields are investigated to identify their impact on the resulting structural behaviour. It was found that severe corrosion degradation could cause an excessive reduction of structural capacity even at 50%. Finally, the results of the present study are compared with the already studied corrosion models showing a highly non-conservative solution of the latter, where the plate thickness is reduced only due to the corrosion degradation progress.