ABSTRACT
The mathematical formulation of the displacement method and force method is similar, but from the point of view of economy of effort one or the other method may be preferable. The displacement method can be applied to statically determinate or indeterminate structures. The displacement or stiffness method of analysis can be applied to any structure but the largest economy of effort arises when the order of statical indeterminacy is high. The procedure is standardized and can be applied without difficulty to trusses, frames, grids, and other structures subjected to external loading or to prescribed deformation. The structure is assumed to be deformed in such a way that a displacement at one of the coordinates equals unity and all the other displacements are zero, and the forces required to hold the structure in this configuration are determined. These forces are applied at the coordinates representing the degrees of freedom.
