Analyse non linéaire par éléments finis des pièces comprimées et fléchies à parois minces

Abstract

A finite element analysis of the ultimate strength of steel thin-walled beam–columns is discussed in this paper. The numerical model used was developed by Akoussah, Beaulieu, and Dhatt and is based on a Lagrangian formula of thin-walled bars. In this model, the law of multiaxial elastic–plastic behaviour was adopted and incorporated on the section's surface by Radau or Gauss type points. Case studies were performed in which different parameters likely to influence the behaviour of beam–columns were used. Corresponding interaction curves were plotted. The results obtained were compared with those of other authors for H sections under biaxial bending, for square or rectangular tubular sections under biaxial bending, and for H sections bended in relation to each of the principal axes. The results emphasize the key role played by shear stress on the bearing capacity of open section compressed members under bending. Key words: shear, compression, finite elements, bending, interaction, elasticity, plasticity.