ABSTRACT
A beam is often connected to other elements which participate in the buckling action, and significantly influence its buckling resistance. This chapter is concerned with the influence of out-of-plane restraints on the elastic buckling of simply supported beams. Braces are provided specifically for the purpose of increasing the buckling resistance, but many other elements, such as sheeting, which are primarily intended for other purposes, also have important restraining actions. Discrete restraints act at points where braces or other restraining elements are connected to the beam, and induce actions which resist the buckling deflections, rotations, and warping displacements. These restraints are usually assumed to be elastic, in which case they may be characterized by their elastic stiffnesses. There have been a number of studies of the effects of central translational or torsional restraints on the buckling of simply supported beams in non-uniform bending, including both the limiting stiffnesses required to cause antisymmetrical buckling.
