05.10: Numerical model for the buckling behaviour of tapered steel members based on experimental tests

Abstract

ABSTRACTTapered steel members can provide optimum cross‐section utilization along the member length, which makes them an interesting alternative to prismatic members due to the economy of this solution. However, EN1993‐1‐1[1] does not provide a clear guidance for the stability design of such members. Recently, the authors have provided simplified stability verification methodologies for tapered columns and beams [2, 3]. The developed methodologies are based on analytical derivations which were validated with advanced numerical simulations.In order to improve the accuracy of the proposed procedures and extend them to members of Class 4 and beam‐columns, an experimental study on tapered columns, beams and beam‐column was carried out. The experiments are used to calibrate a numerical model, incorporating all relevant parameters, such as: geometrical imperfections (local and global) and material imperfections (residual stresses). Unfortunately, the available data on measurements of the material and geometrical imperfections is often found incomplete, even less information is available regarding tapered members. In this paper, firstly a global overview of the experimental programme carried out on web‐tapered steel member is given. The key results from each experiment are summarized; they are further used for the calibration of an advanced numerical model. Finally, an assessment to the magnitude of the adopted geometrical and material imperfections to the member resistance is carried out.