Low cost analysis of building frames for lateral loads

Abstract

A new rational method for the analysis of plane frame by microcomputer is presented. The distribution of the vertical and rotational displacements at the nodes of a story is characterised by the concept of distribution factors which are relative nodal displacements. The distribution factors are allowed to vary from floor to floor and are determined by using three floors at a time. These are calculated once only for floors having identical members. By means of the distribution factors, the number of degrees of freedom is reduced to three at any one floor. Therefore, it is possible for a micro—computer to handle a large number of stories without difficulty. The resulting displacements and internal forces compared very well with full finite element analyses for a number of cases even with sudden changes of stiffness. The method should find applications in other regular structures with arbitrary stiffness distributions.