ABSTRACT
This chapter examines the equations necessary for analysis using the stiffness method and explains the procedure for analysis by considering beams, plane frames, and plane trusses. In the stiffness method, first of all, the compatibility conditions are used to relate the end displacements of the elements with the nodal displacements of the structure. In the stiffness method, the displacements are treated as independent variables. Hence in this method, coordinates indicate displacements. Global coordinates indicate the nodal displacements of the structure. The coordinates corresponding to active the degrees of freedom (DOF) and restrained DOF are known as active coordinates and restrained coordinates. The compatibility condition used in the stiffness method is that the geometry of the deformation must be such that the deformed elements of the structure should fit together at nodes. The stiffness method is more suitable for automatic analysis of structures.
