Comparative Analysis of Steel Structure under Seismic and Blast Loading

Rapid urbanization and increasing demand for performance based design have necessitated the evaluation of steel buildings under both conventional and extreme loading conditions. This study is to investigate comparative effect of seismic and blast loading on a G+10 steel structure using ETABS and LSDYNA software. For seismic analysis, three structural configurations bare moment-resisting frame, concentrically braced frame & steel frame with reinforced concrete shear walls are modeled & analyzed using ETABS in accordance with relevant Indian seismic provisions. The structural responses are evaluated in terms storey displacement, storey drift, base shear and internal force demand. To investigate behavior under extreme loading corresponding to three dimensional numerical where three models are developed in LSDYNA to simulate blast effects using pressure–time histories representative of near field explosions. The blast response is assessed based on peak displacement, stress distribution, energy dissipation and damage patterns. A comparative interpretation is then made between seismic and blast performance for each structural configuration. Results indicate that inclusion of bracing and shear wall significantly enhances stiffness, reduces lateral deformation and improves overall structural resilience under both loading scenarios.