The Selection of Redundant Forces in Structures, with an Application to the Collapse Analysis of Frameworks

Two systematic methods of selecting redundant forces and moments are presented which are suitable for computer programs based on the ‘force’ method of structural analysis. To illustrate the application of the methods a computer program is described which calculates the rigid-plastic collapse load of a two-dimensional structural frame from a specification of its geometry and loading. The program also computes the mode of collapse and produces a drawing of the deformed structure on an automatic plotter.