Ultimate strength of plates with random fields of corrosion

Abstract

This paper presents a study of the collapse strength of corroded plates with random spatial distributions of corroded thicknesses. As an alternative to the uniform reduction of plate thickness due to corrosion or a localized area of reduced thickness, the spatial distributions of the thickness of the corroded plate represented by stochastic simulations of random fields are considered. 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 non-linear finite element analysis. The importance of the spatial representation of the corrosion by random fields as an alternative to the traditional approach, based on a uniform reduction of the plate thickness, is demonstrated.