Virtual displacement and virtual force methods in structural analysis

Abstract

It was demonstrated in Chapter 1 that a satisfactory one-dimensional analysis, except for local effects, can be made for simple beams. However, the stress analysis was made only for the beam cross section so that only the equilibrium equations were needed to get the solution. If the simple beams are assembled into a truss type structure, or into a beam with many supports, then the analysis becomes complicated again because deflection equations as well as equilibrium equations may be needed to get the stresses in the structure. Because of these complicated redundant problems, various special methods have been developed to determine stresses and deflections in redundant beams, trusses, and plates.