Automated design of tier buildings

Abstract

A computer program for the automated design of frameworks in steel tier buildings is described and demonstrated. The design process commences with the input of any initial set of member sies for a given geometry: it is not necessary to begin with good estimates. Cyclic analyses of the building frame and revisions of member sizes then follow. The three-dimensional analysis of the building frame includes the effects of the finite dimensions of moment-resisting connections. Within each cycle of design, wide-flange members are selected on the basis of satisfying the dead- and live-load stress requirements of the 1969 AISC Specification for Structural Steel in Buildings. Each member is then checked for the most critical combination of vertical and lateral loading. The lightest satisfactory size within a prespecified range of sizes is ultimately selected. The output consists of beam and column schedules that show the final sizes and the design conditions leading to their selection. Sample three-story and twenty-story building designs show consistent and rapid convergence to a final design without human intervention between consecutive cycles. With highrise buildings becoming increasingly prevalent, an economical automated design procedure should be of great value to the practicing structural engineer.