Near-field blast loading and transient target response : a collaboration between Sheffield and Cape Town

Near-field blast loads are high in magnitude, short in duration, and non-uniformly distributed across the loaded face of a structural element. Experimental characterisation of near-field blast loading and the resulting deformation of a blast loaded target is made difficult by conflicting requirements, namely: robustness to survive the extreme loading conditions; and sensitivity to accurately measure transient behaviour at high sampling frequencies. As such, there is little definitive experimental data in the literature, and the deformation behaviour of plates subjected to non-uniform impulsive loading is yet to be properly quantified. This paper presents an update on the ongoing collaborative research effort between the University of Sheffield, UK, and the University of Cape Town, South Africa. Direct experimental measurements of blast pressure and impulse using an array of Hopkinson pressure bars (Sheffield), and high-fidelity transient plate deformation measurements using digital image correlation (Cape Town) are jointly-used to assess, and develop predictive methods for, the response of blast loaded plates. Simplified predictive methods, based on knowledge of the applied load rather than an assumed distribution, have been developed which show very good correlation with the experiments and physics-based numerical models.