Improved characterization of the flexural and axial compressive resistance of welded steel box-section members

Abstract

The various existing methods for design of welded steel box-section members have major drawbacks with respect to their ability to represent the limit state responses, their generality in terms handling practical dimensions of box-section members, the ease of their application in real world designs, and the correlation between the resistance predicted by these methods and results from experimental tests and finite element test simulations. The objective of this research is the conceptual and theoretical development and improvement of methods for characterization of the flexural and axial compressive resistance of non-composite welded steel box-section members, and the evaluation of the performance of these methods using data compiled from existing experimental tests and generated from parametric studies performed using finite element test simulations. An important aspect of the calculation of flexural and axial compressive resistance of box-section members is obtaining a good quantification of the ultimate compressive resistance of longitudinally stiffened and non-longitudinally stiffened component plates. The proposed method for calculating the axial compressive resistance of longitudinally stiffened plates is derived using an orthotropic plate idealization, but is expressed as an intuitive and easy-to-use column on elastic foundation model. This model considers the contributions from the longitudinal bending stiffness, transverse bending stiffness, and torsional stiffness of the plate. The proposed methods for characterization of the flexural and axial compressive resistance of non-composite welded box-section members are comprehensive in terms of their handling of limit state responses of practical box-section members, and have a strong theoretical background, yet are simple and design-friendly. The strength predictions using the proposed methods show a good correlation with the results from experimental tests and from parametric studies performed using finite element test simulations.