M. Mashayekhizadeh - M.Sc., Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran Author’s
M Azhari - Professor, Department of Civil Engineering, Isfahan University of Technology, Isfahan, Iran

In this paper, inelastic buckling of unstiffened and stiffened having step variation in thickness arbitrarily in both directions is presented. The problem is accomplished using the Ramberg-Osgood stress-strain relationship for the material and the deformation theory of elasticity for capturing the inelastic behavior is adopted. The analysis is based on the B3-spline finite strip method and in the context of the classical platetheory. Description is given by introducing the concept of multiple knots which modifies the shape functions on the steps positions making the method versatile enough in dealing with any longitudinal change in thickness of the strip element. The problem can be overcome by inserting the multiple knots at the location of the changes. A number of examples are presented to show the accuracy and efficiency of the method.

Inelastic buckling, B3-spline finite strip method, stepped plate, multiple knots