TWO-PHASE TOPOLOGY OPTIMIZATION OF CONCRETE SLABS REINFORCED WITH STEEL USING A BI-DIRECTIONAL EVOLUTIONARY STRUCTURAL OPTIMIZATION APPROACH

Resumo

This paper investigates the application of a two-stage Bidirectional Evolutionary Structural Optimization (BESO) method for the topology optimization of Reinforced Concrete (RC) slabs. The primary objective in a first stage is to achieve a minimum compliance design using only concrete. The second stage then strategically introduces steel reinforcement into highly stressed areas of the optimized concrete structure to improve its structural performance. A fast and efficient finite element analysis (FEA) code implemented in MATLAB, utilizing eight-node hexahedral elements with reduced integration, is employed for the structural analysis and to guide the Soft-Kill BESO process. The self-weight of the structure is considered in the analysis, and the optimization is performed under an approach that can accommodate multiple loading scenarios. A power law penalization scheme is adopted to enforce a clear distinction between solid material-void regions, in the first stage, and between solid-solid during the second stage optimization process. To calibrate the proposed algorithm, a benchmark example was selected from the literature, and the results are compared, demonstrating the accuracy of the implemented approach. The study showcases the capability of this methodology to generate innovative and efficient slab designs with an optimized distribution of concrete and steel, potentially leading to reduced material consumption and enhanced structural efficiency. Visualizations of the optimized material distribution, displacements, and stresses are presented to illustrate the effectiveness of the proposed approach.