Automatic Design of Steel and Composite Steel-Concrete Beams According to NBR 8800 Using Genetic Algorithms

Resumo

Technological advancements have driven the use of new computational techniques and tools in structural engineering, enabling the accurate simulation of the behavior of increasingly slender and complex structures. Making use of such tools, a Python routine was developed for the design of steel beams with non-slender webs, covering welded, rolled profiles, and mixed steel-concrete beams, in accordance with the NBR 8800:2008 standard. The routine incorporates a genetic algorithm (PyGad) for discrete parametric optimization, selecting the most suitable profile among commercial options. The weighting function considers parameters such as inertia, mass, modulus of elasticity, radius of gyration, and bending strength, with weights adjusted by the algorithm. The verification of serviceability limit states and vibration frequencies is also part of the process, offering a comprehensive approach to design and optimization.            After ensuring compliance with the NBR 8800:2008 standard requirements, it was possible to perform several additional analyses with the selected beam, such as cost, weight/performance ratio, boundary conditions, degree of utilization, as well as comparisons between different profile types and beam models. The case study involved the analysis of distinct beam models, allowing an effective comparison between different types of profiles and their characteristics. The results highlighted the program’s ability to provide optimized solutions, considering criteria such as price, weight, boundary conditions and utilization.