Authors' Homepages:   Anthony Bedford  
Wallace Fowler  
Chapter 6: Structures in Equilibrium
"In engineering, the term structure can refer to any object that has the
capacity to support and exert loads. In this chapter we consider structures
composed of interconnected parts, or members. To design such a structure,
or to determine whether an existing one is adequate, it is necessary to
determine the forces an couples acting on the structure as a whole as well
as on its individual members. We first demonstrate how this is done for
the structures called trusses, which are composed entirely of two-force
members. The familiar frameworks of steel members that support some highway
bridges are trusses. When then consider other structures, called frames if
they are designed to remain stationary and support loads and machines if
they are designed to move and exert loads."