Approximate Analytical Model for Multistory Frames

In the preliminary design of tall, slender buildings, the member forces and displacements produced by the action of lateral loads on the structure are of prime importance in proportioning the members. For all but the simplest of structures, the analysis of the structure is a highly indeterminate and complex problem, and for its accurate study, in particular to find the effects of varying girder, column or bracing stiffnesses, electronic computers must be used. Complete analysis of the structural frame by computer programs is presently available. However, the preparation of input data and cost of computation time for investigating alternate framing and bracing schemes may not be justified within the budget of a given project. A method of analytically modeling multistory building frames to reduce the scale of the problem is presented herein. The modeling of large structures into smaller ones enables the designer to analyze very large structures efficiently and economically on a small computer.