Trusses

Abstract

Trusses are flexural members, planar or three-dimensional (space frames), made up of separate members designed principally for axial loads. In most trusses, the members are articulated in triangular patterns; the primary elastic analysis is usually based on axial loads in all members with pin-connected ends. Member connections are made symmetrical about the neutral axes of members or are designed to resist the resulting minor eccentricities. For very large, non-pin-connected trusses, an analysis of bending moments created by axial length changes, and deflections in member with rigid end connections should be performed. Vierendeel trusses are a special type of truss in which web members, usually verticals only, are analyzed for shear, moment, and axial load. The geometry of Vierendeel trusses usually consists of parallel chords, and a square or rectangular pattern of web and chord members, although occasionally with a top chord steeply pitched in one or both directions.