ABSTRACT
A truss appears to be a structural element in which small components are assembled into a larger form compatible with the distance to be spanned. Contemplation of the assembly process at once suggests a structural form totally different in kind from a beam. The fundamental structural logic underlying the adoption of a trussed form can be appreciated by considering what happens to the stress at the extreme fibres of a rectangular beam as it doubles its size. Castellated beams are frequently chosen by architects for the visual appeal of the repetition of the hexagonal voids where the beams are not concealed by a false ceiling. Several different sectional shapes are used in the fabrication of lattice girders, varying from angles, tees, channels and hollow sections. The reinforced concrete truss comes into its own as a Vierendeel girder, a structural form named after the Belgian engineer, Professor Arthur Vierendeel, who devised it in 1896.
