Influence of normative criteria on the design of timber trusses: comparative analysis between ABNT NBR 7190-1:2022 and NDS (2018)

Resumo

Timber structures are widely used in roofing systems due to their structural efficiency, low self-weight, and sustainable use potential. However, the performance of these structures depends directly on the normative criteria adopted during design, since different approaches can result in distinct structural responses for the same geometric configuration. In this study, a comparative analysis was performed between the design procedures established by ABNT NBR 7190-1:2022 and the National Design Specification for Wood Construction (NDS, 2018), applied to a Howe-type timber truss intended for a warehouse roof. The analyses focused on normal compression and tension stresses, and the displacement of the most stressed structural elements. The results indicated differences between the normative procedures, especially regarding load combinations, adjustment factors, and material properties considered. Close agreement was observed between the compression and tension values obtained by both approaches, while displacements showed a more significant divergence. Despite the quantitative differences verified, both standards led to the same conclusion regarding the structural inadequacy of the analyzed configuration under the studied conditions. The results highlight the influence of normative criteria on structural design and reinforce the importance of properly applying the corresponding technical procedures to the project context.