Stoke Heath, Bromsgrove, West Midlands, Great Britain
Dr James Broughton tells the BBC why he decided to make a bike out of bamboo.
A partnership between Oxford Brookes University and UK based RAW Bamboo Bikes has seen the launch of a mountain bike frame built from bamboo tubing.
Mechanical engineering experts at Oxford Brookes are building on their leading research which ranges from the development of compounds for ballistic armour, to the use of adhesives and sealants for the aerospace, automotive and construction sectors.
The objective of the present study is to describe the progressive debonding of inclusions in particle or fibre reinforced composites. To do so, the mean-field homogenisation scheme of Mori-Tanaka is enriched to take into account imperfect interfaces. The interfaces are modelled by a bilinear Cohesive Zone Model (CZM) taking into account normal and tangential effects. Results obtained with this new mean-field homogenisation scheme are compared to 2D FE-based numerical simulations that are used as reference results. The effects of inclusions volume fraction and size are also observed.
The recycling, recovery and reuse of End-of-Life Vehicles (ELVs) has raised worldwide concerns. This paper identified drivers for new joining solutions in the automotive industry and specifically reviewed current use of adhesive technology. From an ELV recycling point of view, rapid assembly and disassembly joining solutions were identified as key technology drivers. Innovations in adhesive disbonding technologies were reviewed and suggestions for the most promising future disbonding technologies have been proposed.
The present study aims at describing the debonding phenomenon of a particle embedded in an elastic matrix. Two types of fracture mechanics approaches are developed and compared in this context. The phenomenon is analytically described using a finite fracture mechanics approach, while numerical simulations are performed using a cohesive zone model to describe the decohesion process. Both methods rely on two mechanical parameters: the interface strength, σmax and the fracture energy, Gc, of the interface. Both modelling approaches produce results that show larger particles tend to debond before smaller ones although noticeable differences are observed, especially concerning the relationship between the critical load and the particle radius: in the framework of the FFM, the critical load is inversely proportional to the square root of the particle radius, while when using CZM, the critical load is inversely proportional to the particle radius.
The automotive and aerospace industries are keen to reduce their environmental impact and so have looked to move to lightweight materials. This creates issues in terms of joining, using and disposing of dissimilar materials. Oxford Brookes has therefore worked with national and multi-national companies in the adhesive, materials, automotive and aerospace industries to try to solve these problems. This has resulted in high quality research publications, innovative test equipment, improved numerical methods, novel designs, design guidelines, manufacturing procedures, British Standards, patents, commercial products and further funding. The impact of the work has global safety, environmental and economic benefits with multi-national aerospace and automotive companies implementing the results in current developments.
Cavitation erosion is a major challenge for marine and fluid machinery systems. This study investigated the erosion performance of two as-cast aluminium alloys exposed to acoustic cavitation in water at temperatures of 10–50 °C and those were then compared with an extruded wrought alloy tested specifically at the temperature of maximum erosion. The results showed that the as-cast A380 alloy displayed exceptional resistance to cavitation erosion, with the lowest mass loss and surface roughness. This finding suggests that the as-cast A380 alloy is a suitable choice for lightweight, high-performance components in applications where cavitation resistance is critical.