an COMPARATIVE ANALYSIS OF DISPLACEMENTS AND DEFORMATIONS IN PRATT, HOWE AND BELGIAN STEEL TRUSSES USING ROBOT STRUCTURAL ANALYSIS®

Abstract

The study of steel trusses is fundamental in civil engineering, as these structures offer an ideal combination of strength and material efficiency, being widely used in building roofs. Understanding the structural behavior of different types of trusses under various load conditions is essential to ensure the safety and efficiency of projects. This article conducts a comparative analysis of displacements and deformations in Pratt, Howe, and Belgian steel trusses using Robot Structural Analysis^® software. The adopted methodology included steps such as preparation, configuration, and conception of the structure in the software; definition of materials and sections; truss modeling; calculation and application of loads; execution of the analysis; and processing of the results. The considered loads include self-weight, trapezoidal roof tile weight, and wind action at 0° and 90°, following the NBR 6120:2019 and NBR 8800:2008 standards. The results indicated that the ELU_Comb1 combination caused the greatest displacements among the Ultimate Limit State combinations, while the ELSComb2 combination was the most critical among the Service Limit State combinations. Specifically, Model 3 (Belgian truss) showed the smallest displacement (δ_Max = 0.6 cm) and the best Ncsd/Ncrd ratio (0.167), standing out as the most efficient option. In contrast, the Howe truss exhibited the largest displacement (δ_Max = 0.8 cm) and a lower resistance ratio (Ncsd/Ncrd = 0.188). It is hoped that this study will contribute to the judicious selection of steel trusses in roofs, providing a solid foundation for future research and applications in engineering.