Impact Loads in Steel Connections

After attacks on World Trade Center (2001), Madrid (2004), London (2005) and Mumbai (2008), special attention was given to the study of robust structures subjected at different accidental loads, allowing localized failure without being damaged to an extent disproportionate to the original cause. The collapse of the World Trade Center (WTC) showed problems in the design of structural elements: columns collapse, beams buckling and brittle failure of connections. Concerning this last topic, it was realised that the joint structural details plays very significant role behaviour in struc-tures subjected to accidentals loads. The accidental loads may result from an object impact, blast, explosions, earthquake and fire.

The work presented in this paper corresponds to the first work package of the research project Im-pactfire, currently in development at the University of Coimbra; the behaviour of steel beam-column connections against accidental impact loading is the main objective of the project. The cur-rent paper is focused in: i) characterization of the impact scenarios in steel structures, ii) influence of strain rate sensitivity steel material model, and iii) previous research studies on the behaviour of steel beam-column connections against impact loading. At the end, the experimental programme of the research project Impactfire is presented.