Effect of Span Length on the Doubly Optimized Prestressed Concrete Beams

Abstract

The current work investigates the changes occurring in the optimized shape and cable layout of prestress concrete beams due to the change in span length. A single prestressed beam of fixed length is taken, and its span length is changed by placing supports along the length. The prestressed beam is then optimized for each case and the effect of the changed span over the optimized cable layout and concrete shape under different loading conditions is studied. The optimization of the prestressed beam is done using an indigenously developed software labeled “Simultaneous Shape and Cable Optimization” (SSCO). The software SSCO works on a fuzzy regulated integrated zero-order procedure where the concrete is simulated as a discretized continuum using nine noded Lagrangian elements, while the prestressing wire is represented as a curvilinear, three-noded bar element mapping a B-spline profile. The present objective of the optimization is to attain an optimized concrete shape and cable layout for a given predefined external load while removing the tensile stresses (< 0.5 N/mm2) in the prestressed beams and to find out the optimum number of spans which will strike a perfect balance between the amount of material saved due to optimized shape and the number of spans needed to be given. © 2024, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.