M. Mashayekhizadeh - MA, Isfahan University of Technology, Isfahan, Iran
M. Azhari - Professor, Isfahan University of Technology, Isfahan, Iran

The devastating effect of corrosion in steel structures in marine environments has made these structures so vulnerable in terms of loss of structural stability. The localized corrosion area generally leads to degradation in thickness, makes it stepwise in random positions, needing a reliable method to model and analyze the abrupt changes. Therefore, in this paper, buckling analysis of stiffened and unstiffened plates having step variation in thickness due to localized corrosion is considered. This analysis is based on the B3-spline finite strip method and in the context of the classical plate theory. Description is given by introducing the concept of multiple knots which makes the method versatile in dealing with any abruptly longitudinal change in the thickness of the strip element. The problem can be overcome by inserting multiple knots at the location of the changes. A number of numerical examples are presented to show the accuracy and efficiency of the method.

localized corrosion, multiple knots, stepped plate, B Spline functions