Improvised explosive devices (IEDS) cause thousands of injuries and deaths each year. In many cases, explosives are embedded with solid objects or encased in housings designed to fragment upon detonation. Thus, damage to structures and nearby people ensues from both the air-blast loading and the impact of small solid particles travelling at high velocity. These loads and the damage they cause need to be measured and understood so that engineers can provide protection against them.
Recent advancements in experimental capability at the University of Sheffield provide two forms of technology that can be employed to characterise the loading and behaviour of structures subjected to combined blast and fragment-impact type loads. The first system uses an array of hopkinson bars to measure the pressure-time history at discrete locations across a rigid target structure; these loads can be integrated to provide a measure of the specific impulse across a surface. The second system allows the measurement of out-of-plane transient surface displacements of a flexible target under blast loading, by using Digital Image Correlation to analyse high-speed video footage. The initial velocity profile across the target plate can be obtained, which can be used to find the spatial impulse distribution arising front he explosive detonation.
This project proposes to use both systems to characterise the loading and structural response of a plate when subjected to combined blast and fragmentation-impact loads. It is anticipated that the project will examine the factors influencing the nature of the combined loading and response (such as stand-off distance, fragment impact geometry, explosive charge dimensions) using state of the art experimental facilities at Buxton and commercial computational software.
The candidate should have background knowledge in imaging techniques (high speed video), as well as prior education and experience in structural mechanics. You will be joining The Blast and Impact Research Group at The University of Sheffield, with 4 academic staff members, 3 postdoctoral researchers, and 13 PhD students. The Blast and Impact Research Group has decades of research experience into the mechanisms of loading arising from explosion events and their subsequent effects on structures and materials. Our goal is to determine the underlying mechanisms involved in the loading and responses arising from explosion and impact events with a view to improving the safety of people and infrastructure at risk. Our work balances fundamental scientific research and real-world impact, allowing us to play a key role in the development of new solutions to protect people and structures against the damaging effects of high explosive blasts.
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