Large Displacement Inelastic Analysis of Beam-Columns

Abstract

The formulation of a variational virtual work equation for describing internal work for an arbitrary thin-walled beam of open cross section subjected to large displacements is reviewed. The equation is specialized to treat I-sections and is discretized by the finite element method in terms of twelve displacement coordinates per node. A procedure for solution with inelastic material properties (Shanley theory) is examined in detail, as well as some programming considerations. Solutions for a trilinear stress-strain relationship, including the effect of residual strains, are compared with experimental results. Good agreement is obtained for inelastic biaxial bending of a beam-column and for inelastic lateral buckling of a beam.