INTERACTIVE BUCKLING OF AN ELASTICALLY RESTRAINED TRUSS STRUCTURE

Interactive buckling of an elastically restrained truss structure is investigated by using an improved version of the Byskov-Hutchinson perturbation analysis. The mechanical model consists of two horizontal beams connected by rigid diagonals, whose out-of-plane displacements are prevented by a continuous distribution of linear springs. When the two horizontal beams are compressed, three buckling modes are possible: one overall in-plane mode and two local (lateral and torsional) modes which, for a particular choice of the geometry of the structure, may occur nearly simultaneously. Three nonlinear equilibrium equations are derived in the amplitudes of the three buckling modes and solved numerically for given initial imperfections.