Efficient storey lateral stiffness estimate and gradient-based multi-objective optimization of reinforced concrete frames with hybrid semi-rigid precast connections

Abstract

By fully utilizing the designability of semi-rigid connections in precast concrete structures, the gradient-based interior point algorithm is applied to perform a two-stage optimization with the objectives of minimum material cost and a target interstorey drift ratio distribution. To obtain an efficient storey lateral stiffness estimate for optimization, the modified Muto’s method is further extended to address hybrid distributions of connections. Based on the characteristics of the modified Muto’s method, the dual objectives of attaining the target interstorey drift ratio distribution and minimizing the material cost are treated as two separate objectives in the optimization. A case study on precast concrete frames with different storeys, connection parameters and target interstorey drift ratio distribution patterns demonstrates the efficiency and accuracy of the proposed approach. Such an approach could be suitable for the preliminary design of precast concrete structures with hybrid semi-rigid connections.