Browsing by Author "Powell, Daniel"

Now showing 1 - 6 of 6
  • Thumbnail Image
    ItemOpen Access
    Doping with Tungsten - Bad for Humans, Great for Tanks
    (Cranfield University, 2022-01-11T15:44:28Z) Powell, Daniel
    The distribution of energy within an armour system is a fundamental principle. The joining of the hard disruptive outer layer and soft absorbing backing layer is often a source of weakness in armour systems, causing premature failure and thus defeat of the armour. Novel adhesive techniques to join these thin layers together could have a greater impact on the armour performance with minimal additional weight. Doping epoxy with tungsten powder is one such technique that is currently being considered.
  • Thumbnail Image
    ItemOpen Access
    Improving adhesion in bonded ceramics through novel additively manufactured surface geometries
    (Cranfield University Defence and Security, 2024-11-13) Powell, Daniel; Appleby-Thomas, Gareth; Painter, Jonathan
    Many high-value industries (including medical, aerospace, and defence) utilise ceramics for their favourable properties, such as high hardness, low thermal / electrical conductivity, and chemical resistance. The latter property results from chemical inertness. However, this inertness leads to weaker bond strengths when joining ceramics with other materials, as is often required to overcome their brittle nature and low tensile strength.Geometries can be introduced to the surface of a material to act as adhesion promoters through increasing the surface area of the bond, but more interestingly through mechanical interlocking between the ceramic and bonding material. Whilst this would be impossible to achieve through conventional manufacturing techniques, additive manufacturing (AM) can create these novel surface geometries. This work pushes the capabilities of ceramic AM at a scale of no greater than 500 µm, finding the limits of the current technology. Furthermore, the potential for increased bonding through the generated geometries is investigated.
  • Thumbnail Image
    ItemOpen Access
    Novel Ceramic Armour for Land Vehicles: Identifying the Chink in our Knowledge
    (Cranfield University, 2020-11-30 16:58) Powell, Daniel
    Vehicle armour is a complex multi-material system, typically comprising of both ceramics and metals. It must meet highly demanding performance criteria; resistance to penetration (often at incredibly high strain rates) must be maximised whilst weight and encumbrance must be minimised. The principles of armour are well-established, although much of the science is under-researched. Some notable knowledge gaps are the adjoining between the ceramic and metal at the interface, the transmission of energy through this interface and how this contributes to armour being defeated. This project aims to further investigate and understand what happens at this interface, ultimately intending to optimise future armour systems. This is to be achieved through computational modelling, initially investigating different combinations of materials and interlayer thicknesses. These models can then be validated against basic ballistic test data, replicating the conditions of the simulations. Once validated, the models can test innovative and non-conventional interlayer geometries, thickness and material combinations, highlighting promising avenues of further research. Whilst still in the infancy of this research, a spreadsheet has been created to allow the visualisation of damaging shock waves through user-defined materials, layer thicknesses and projectile materials. Once validated, it is intended to make this accessible to the wider scientific community.
  • No Thumbnail Available
    ItemOpen Access
    Visualising penetration in armour
    (Cranfield University, 2022-01-11T15:45:37Z) Powell, Daniel
    The human eye, CT scanning, X-ray radiography and Computer Aided Design (CAD) can all be used to visualise penetration in armour systems. This digital image demonstrates how these advanced techniques help us see a story that often seems non-existent to the human eye. X-ray radiography in the x and y axis paired with subsequent computer modelling allows the recreation of the crater and embedded material in 3D, enabling detailed analysis of the armour penetration. The volume of penetration can be measured with 95% accuracy from this CAD model when compared to the more expensive and complex, yet highly accurate, CT scanning. This demonstrates the reliability of this relatively simple and accessible methodology for quantifying damage in armour systems.
  • Thumbnail Image
    ItemOpen Access
    Visualising penetration in armour
    (Cranfield University, 2022-01-11T15:50:02Z) Powell, Daniel
    The human eye, CT scanning, X-ray radiography and Computer Aided Design (CAD) can all be used to visualise penetration in armour systems. This digital image demonstrates how these advanced techniques help us see a story that often seems non-existent to the human eye. X-ray radiography in the x and y axis paired with subsequent computer modelling allows the recreation of the crater and embedded material in 3D, enabling detailed analysis of the armour penetration. The volume of penetration can be measured with 95% accuracy from this CAD model when compared to the more expensive and complex, yet highly accurate, CT scanning. This demonstrates the reliability of this relatively simple and accessible methodology for quantifying damage in armour systems.
  • Thumbnail Image
    ItemOpen Access
    Visualising the Dispersion of Particles Within a Functionally Graded Material
    (Cranfield University, 2022-11-22T14:40:10Z) Powell, Daniel
    Functionally graded materials (FGMs) are designed to carefully alter material properties along a selected axis. This image shows FGMs created through mixing varying percentage volumes of high-density tungsten powder (in orange) with a low-viscosity epoxy (in white). Black regions show pores. As the epoxy cures the tungsten particles settle at various depths under gravity, notably in the 1%, 5% and 10% samples. Whilst there are multiple uses for FGMs, this research investigates if they could control the passage of damaging shock waves through a ceramic armour system, especially at the interlayer between a ceramic and metal.