COMPUTER-AUTOMATED DESIGN OF REINFORCED-CONCRETE FRAMEWORKS

This paper presents an efficient computer-based method for the optimal design of reinforced concrete building frameworks. The width, depth, and longitudinal reinforcement of member sections are taken as the design variables. The strength constraints for the design are formulated using both member capacity sensitivities and structure response sensitivities. An optimality criteria method is applied to minimize the cost of concrete, steel, and formwork subject to constraints on strength and stiffness. Two reinforced concrete framework examples are presented to illustrate the features of the design optimization method. It is shown that the design method provides an effective iterative optimization strategy that converges in relatively few cycles to a least-cost design of reinforced concrete frameworks satisfying all relevant requirements of the governing design code. The iterative process is insensitive to the (arbitrarily) selected initial design and converges smoothly to a final design involving member dimensions and reinforcement percentages consistent with usual design practice.