Modelling the fire resistance of steel-to-timber dowelled connections loaded perpendicularly to the grain. (July 2019)

• Record Type: Journal Article
• Authors: Palma, Pedro; Frangi, Andrea
• Is Part Of: Fire safety journal. Volume 107(2019)
• Page Start: 54
• Page End: 74
• Publication Date: 2019-07
• Subjects: Timber -- Fire -- Connections -- Simulations -- Steel-to-timber connections -- Fire resistance; Fire prevention -- Periodicals; Incendies -- Prévention -- Recherche -- Périodiques; Fire prevention -- Research; Periodicals; 628.92205
• DOI: 10.1016/j.firesaf.2017.12.001
• Languages: English
• ISSNs: 0379-7112

Abstract

Abstract: A framework to model timber connections at normal temperature and in fire, based on combined finite-element (FE) heat-transfer analyses and temperature-dependent Johansen-type load-carrying models, was developed and applied in a parametric study of previously tested beam-to-column steel-to-timber dowelled connections. Comparison with experimental results shows that the FE heat transfer models provide good estimates of measured temperatures and the load-carrying model gives good approximations of the load-carrying capacity at normal temperature (for dowel and embedment failures) and under standard fire exposure. For the degrees of utilisation expected in fire E fi / R 20 ≈ 0.3, the developed models are able to predict the failure mode of each dowel and the expected load-carrying capacity. Simulation results showed a clear influence of the thickness of the side members on the fire resistance of the analysed connections. The influence of dowel spacing is not so clear, as it also depends on the dowel diameter. A smaller dowel diameter seems to slightly improve the fire resistance, namely for smaller degrees of utilisation or thinner side members, but compromises the load carrying capacity at normal temperature. Highlights: Framework to model timber connections in fire applied in parametric study of previously tested beam-to-column connections. Models provide good estimates of temperatures, load-carrying capacities, and failure modes. Results show a clear influence of the thickness of the side members on the fire resistance of the analysed connections. Influence of dowel spacing is not so clear, as it also depends on dowel diameter. Smaller dowel diameter slightly improves fire resistance, but compromises load carrying capacity at normal temperature.