Browsing by Author "Brown, Laura"

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    Design of multi-layered protection against guided mortar threats through numerical modeling
    (Elsevier, 2023-01-28) Thawani, Bonny; Lim, Seng Kiat; Brown, Laura; Critchley, Richard; Hazael, Rachael
    The trade – off between protection and weight is a constant consideration when designing a portable protective solution. Greater mobility is a desirable attribute and protection must therefore adapt, prompting a demand for lightweight, simple to construct, low-cost and effective ballistic protection systems. High strength and ductility, wave spreading capability and good energy absorption are key properties for ballistic protection. Four materials, polycarbonate, Kevlar®-epoxy, polyurethane foam, and aluminium alloy, possess these properties and were selected for analysis by numerical simulation. Multi-layered configurations were proven to be an optimal solution, by exploiting the advantages of each material without having large penalties of mass and cost. Numerical modelling using ANSYS AUTODYN® is used to simulate monolithic and multi-layered target configurations, to obtain the penetration mitigation performance. The results are analysed to select configurations based on different requirements, such as lowest cost, lowest mass, best performance, and optimal configuration which balanced the three key parameters mentioned. The optimal configuration of Aluminium, Kevlar-Epoxy, Polyurethane, and Polycarbonate has layers with thickness of 7, 3, 38, 2 mm respectively with a total mass of 7.97 kg, total cost of $39.86 and penetration of 29.34% (14.67 mm). Polynomial relationships between performance and mass/cost are also determined.
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    Development of Sustainable PPE for Higher Threat Clearance Operations by Humanitarian Organisations
    (Cranfield University, 2024-01-22T10:08:40Z) Brown, Laura
    Poster contribution to the Defence and Security Doctoral Symposium 2023 
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    Development of sustainable PPE for higher threat clearance operations by humanitarian organisations
    (Cranfield University Defence and Security, 2024-11-13) Brown, Laura
    In 2020 it was reported that 59 countries and territories were still contaminated by both landmines and other unexploded ordnance. The threats faced by those in the demining industry have increased due to the more frequent use of IEDs. These will generally have a larger charge size than conventional mines. PPE therefore needs to be improved to keep in line with these new threats. Recently there has been a push from industry to include more sustainable materials within armour production, with some already showing some promise within literature. Ramie (Boehmeria nivea) fibres have also been previously used in studies surrounding in soft armour, hard armour, and multi-layered armour system (MAS) and Flax (Linum usitatissimum) has been investigated with regards to hard armour panels. The hard panels manufacture for this project were produced using the vacuum resin infusion method, a low-cost method that is easy enough to be used in low scale operations. A number of different configurations were created, including natural fibre para-aramid and all natural fibre combinations, all of which were subject to different mechanical tests to assess their strengths. The ballistic testing, completed on a single stage light gas gun, showed the 50% Ramie 50% para-aramid panels outperformed all others tested. A significant observation was the different fracture mechanics seen on the back face of each of the panels, something that may have contributed towards their good performance. The all-natural Flax Ramie panels also showed some significant results, with these panels outperforming several other panels which contained para-aramid materials. Future work in this project will include assessing the best performing panels under increased ballistic loads, as well as looking at the suitability aspect of these panels to determine whether they can be potentially recycled once they have been used.
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    Development of Sustainable PPE for Higher Threat Clearance Operations by Humanitarian Organisations
    (Cranfield University, 2022-11-24T17:32:10Z) Brown, Laura
    Humanitarian demining is a hugely important task being undertaken all over the world with 59 countries and territories still contaminated by landmines and unexploded ordnance as of 2020. Personal Protective Equipment (PPE) for demining has traditionally been designed to protect against threats from legacy mines. However, over the last decade there has been an increase in the charge sizes used in these devices. It is currently unknown how the current PPE will perform and interact with these larger threats. Therefore, there is a need to understand whether improvements need to be made to both the standards used and the PPE itself. PPE that would be used by the police and militaries for these higher charge threats, e.g. IEDs and UXO, is highly developed, however it is extremely expensive and would be inappropriate for the demining industry. This project is therefore working to bridge the gap and help produce an effective and low-cost PPE solution that can be used by the humanitarian sector.
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    Development of Sustainable PPE for Higher Threat Clearance Operations by Humanitarian Organisations
    (Cranfield University, 2024-01-17T17:58:27Z) Brown, Laura
    3MT contribution to the Defence and Security Doctoral Symposium 2023 
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    ItemOpen Access
    Development of Sustainable PPE for Higher Threat Clearance Operations by Humanitarian Organisations
    (Cranfield University, 2022-11-22T11:35:53Z) Brown, Laura
    Humanitarian demining is a hugely important task being undertaken all over the world with 59 countries and territories still contaminated by landmines and unexploded ordnance as of 2020. Personal Protective Equipment (PPE) for demining has traditionally been designed to protect against threats from legacy mines. However, over the last decade there has been an increase in the charge sizes used in these devices. It is currently unknown how the current PPE will perform and interact with these larger threats. Therefore, there is a need to understand whether improvements need to be made to both the standards used and the PPE itself. PPE that would be used by the police and militaries for these higher charge threats, e.g. IEDs and UXO, is highly developed, however it is extremely expensive and would be inappropriate for the demining industry. This project is therefore working to bridge the gap and help produce an effective and low-cost PPE solution that can be used by the humanitarian sector.
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    Quantification of fragmentation capture materials and an assessment of the viability of economical alternatives: a preliminary study
    (The Royal Society, 2023-09-11) Read, James; Ritchie, Thomas; Brown, Laura; Thawani, Bonny; Bloodworth-Race, Susie; Hazael, Rachael; Critchley, Richard
    High pressure, high temperature events need to be quantified experimentally. Where fragmentation occurs i.e. against Personal Protective Equipment (PPE), there is a requirement for both a reliable and repeatable measurement of numerous experimental metrics. Typically, the most critical is calculating the energy absorbed by the target material, to characterise target performance. This is achieved by detonating a device and capturing a proportion of the fragmentation in a suitable material that can achieve successful recovery of all fragmentation produced. Therefore, allowing the estimation of the target’s response using the depth of penetration within the capture material which allows the calculation of energy absorption. The current standardised fragmentation capture material used within the United Kingdom is known as strawboard. Although effective, this material is both expensive and limited in its availability. This study explores the classification of strawboard to provide a suitable baseline to compare against Medium Density Fibreboard (MDF) and flooring underlay which represent two more economically friendly alternatives on the open market. It was found that the uniformity of response for the MDF material was better than that of strawboard, due to its reproducibility between batches and velocity ranges. To further explore this phenomena, high explosive trials were conducted, further demonstrating MDF to be a viable, reliable, and cheaper alternative.