Ultimate strength of plates with random fields of corrosion

This paper presents a study of the collapse strength of corroded plates with random spatial distribution of corroded thickness. In alternative to the uniform reduction of plate thickness due to corrosion or a localised area of reduced thickness, it considers the spatial distribution of the thickness of the corroded plate represented by stochastic simulation of random fields. A non-linear time dependent corrosion model is used to define the probabilistic characteristics of the random fields based on corrosion data measured in plate elements at different locations of several bulk carriers. The random fields of corrosion are discretized and the collapse strength of the plate is then assessed by nonlinear finite element analysis. The importance of the spatial representation of the corrosion by random fields in alternative to the traditional approach based on a uniform reduction of plate thickness is demonstrated.