ABSTRACT
Trusses are commonly used in the design of buildings, bridges, and towers. They are triangulated frameworks composed of slender bars whose ends are connected through bolts, pins, rivets, and so on. Truss structures create large, open, and uninterrupted space, and offer lightweight and economical solutions to many engineering situations. This chapter explores the bar elements which can be used in truss analysis. The concept of the shape functions is introduced and the derivations of the stiffness matrices using the energy approach are introduced. Given the fact that a truss is an assembly of axial bars, it is generally satisfactory to treat each truss member as a discrete element—bar element. The chapter formulates the equations for the bar element based on the 1-D elasticity theory. It derives the same stiffness matrix for the bar using a formal approach which can be applied to many other more complicated situations.
