Modelagem numérica, análise estrutural e proposta de otimização de cobertura metálica

Abstract

In the design of a steel structure for an industrial shed, there is a wide range of possibilities that can be adopted for the structural arrangement of the building. In this context, the present work presents the structural analysis of a steel shed designed to house a healthcare facility of the polyclinic type, originally conceived with trapezoidal truss-type transverse frames. The objective was to critically analyze the initial structural design and assess its performance based on Brazilian technical standards, particularly NBR 8800:2008 and NBR 14762:2010. The main goal of this study was to evaluate the normative compliance of the original design and, based on that, propose and compare different typologies of transverse frames in terms of steel consumption and structural performance. The adopted methodology was based on numerical modeling and structural analysis carried out using the Cype3D software, through which both the original project and the comparative analysis were verified according to Ultimate Limit States (ULS) and Serviceability Limit States (SLS). A parametric study was developed with different structural alternatives for the transverse frames, including solid-web beam frames, parallel chord trusses, trapezoidal trusses, and arch trusses. All models were subjected to the same loading conditions, following the normative combinations required for structural design. The criteria adopted for comparative evaluation were the steel consumption rate, as an economic indicator, and structural displacements, as indicators of stiffness and overall performance. The methodology applied in this work enables not only the technical verification of an existing project but also the search for optimized and more efficient solutions for the structural design of steel sheds, contributing to safer, more economical projects in accordance with technical standards. The analyses revealed significant inconsistencies, such as members with utilization ratios exceeding 100%, slenderness indices above normative limits in compressed profiles, absence of stabilizing elements such as tie rods, and vertical displacements exceeding allowable limits. It was also found that the geometry adopted in the Truss (featuring a span-to-rise ratio of L/17 and a roof slope of only 8%) compromised the overall structural performance, leading to higher internal forces. The results of the parametric study showed that the solid-web beam frame presented the highest steel consumption, although it complied with verification criteria. The arch truss stood out for having the lowest vertical displacement, though with intermediate steel usage. The trapezoidal truss demonstrated the best overall performance, with the lowest steel consumption rate and acceptable displacement values, thus being considered the most efficient structural solution within the analyzed scope. The comparison between models highlighted the importance of properly selecting the structural typology, considering both mechanical behavior and the rational use of materials.