Influence of thermal properties on the numerical analysis of timber structures in fire

Resumo

The structural performance analysis of timber under fire conditions considers the changes in its thermal properties as the temperature rises. EN 1995-1-2 (2004) proposes values for thermal conductivity, specific heat, and the ratio between density and oven-dry density for softwoods, although other approaches are also presented in the literature. Therefore, this study aims to evaluate the thermal behavior of timber considering the thermal property proposals from Audebert et al. (2013), EN 1995-1-2 (2004) and Fernandes (2022), applied to thermal numerical models of timber beams under fire conditions, with validation against experimental models. The numerical modeling was performed using the finite element software Abaqus. The models were validated based on experimental results available in the literature, considering glued laminated timber elements made from two wood species (Pinus and Lyptus) and timber elements representing connections with metal dowels. Comparisons calculated from numerical, experimental and analytical estimates determined for the selected samples are presented. The proposals by Fernandes (2022) and Audebert et al. (2013) yielded more representative results considering the experimental analyses performed. These results highlight the importance of conducting in-depth studies with native species to establish specific values for thermal conductivity and specific heat.