# Minimum Cost Topological Design of Steel Sway Frames

*A method is given for the minimum cost design of rigidly jointed, multistorey steel sway frames in which economic and some architectural requirements determine their final shape. Appropriate ‘differential’ deflection constraints are imposed to control the sway in each storey. The object is to minimise the total cost of the constnrction, including material and any other handling costs. The latter is expressed as a Tied charge ’ to penalise a member retained in the final topology. The problem turns out to be that of non-linear, mixed variable integer programming. Suggestions are made to simplifr the mathematical approach, and examples are given to demonstrate the flexibility of the method.
K.I. Majid, P. Stojanovski and M. P. Saka*