Numerical damage evaluation assessment of blast loaded steel columns with similar section properties

In the last years, the increase of blast and terroristic attacks in the vicinity of critical structures and facilities highlighted the importance of appropriate simulation and design methods for blast loaded structures. Within a building exposed to blast, columns act as key components, being asked to sustain ordinary gravity and wind loads, but also possible additional exceptional loads like earthquakes or explosions. In this paper, the dynamic behavior of steel columns under blast pressures is numerically investigated. Careful consideration is spent – based on validated Finite Element (FE) models – for the blast performance of steel columns with different cross-sectional shapes but similar mechanical properties (i.e., total area, moment of inertia and elastic section modulus). Explicit FE analyses are carried out on a wide set of configurations, including variations in (a) cross-section properties, (b) boundary conditions and (c) explosions features. In doing so, the accuracy and reliability of different FE models (i.e., based on solid, shell and beam elements) are also investigated, both in terms of global/local results and computational cost of the dynamic simulations. As key damage parameters due to blast, the maximum displacement and the residual load carrying capacity of the examined columns are examined. The collected parametric results show that the cross-sectional shape only slightly affects the global dynamic behavior of steel columns, especially in terms of residual capacity. Moreover, compared to computationally expensive full solid models, the reliability and accuracy of geometrically simplified shell and beam is discussed, with respect to the observed responses and intrinsic computational efficiency.