Non-Linear Modelling of Reinforced Concrete Columns Subject to Internal Explosions and Uplift Effects: CFD and Applied Element Methods

This paper presents research towards the behaviour of reinforced concrete columns subjected to complex loading environments characteristic of internal blast. Historic events have demonstrated that confined blasts can induce significant upward tensile forces on load-bearing columns. These time-dependant upward forces act simultaneously with lateral blast pressures, coupled with the strength of concrete columns falling rapidly due to a net reduction in the axial compression force. To date, a large body of research exists regarding the vulnerability of concrete columns to external explosions, but no comprehensive studies have been conducted to understand column behaviour under complex internal blast environments. In this research, numerical models of concrete columns are constructed utilizing the Applied Element Method and benchmarked through comparative studies against experimental data. Internal detonations and the subsequent wave propagation featuring multiple reflections and blast venting are accurately simulated using CFD with independent load verification using Autodyn. Parametric studies were conducted to understand the influence of perimeter wall type, (i.e. rigid, open) in relation to blast wave reflections and the upward tensile effect on internal column members. The results of this research will benefit both academics and practitioners involved in designing protective structures covering both civilian and military construction.