08 University of Plymouth Masters Dissertations
https://pearl.plymouth.ac.uk/handle/10026.1/5563
Masters dissertations from University of Plymouth students. Available only to University of Plymouth staff and students.2024-03-29T06:38:14ZThe Manufacture and Testing of Perforated Composite Acoustic Panels
https://pearl.plymouth.ac.uk/handle/10026.1/4531
The Manufacture and Testing of Perforated Composite Acoustic Panels
Blackburn, Robert
The recent expansion of civil aviation has been accompanied by significant growth in the use of advanced composite structures with carbon fibre reinforced epoxy often the material of choice in many structures. Composite structures have a long history in engine nacelles, where an optimised design can both fulfil structural requirements and simultaneously provide an acoustic liner for sound attenuation. The "traditional process" involves the drilling of high-density multiple holes with the twin consequences of extended production times and machining waste. Elimination of this perforation process is an attractive target in a commercial environment. Structural performance could be improved by retaining fibre continuity whilst controlling fibre paths around the perforations through a moulding approach. This thesis reports an investigation to evaluate novel approaches to moulding multiple perforations in composite structures and the application of those approaches in both traditional pre-preg and resin infusion processing technologies. Two approaches were explored: castable soluble pins and an adaptation of z-pinning technology. The composites produced using one of these techniques were subjected to mechanical testing (tension, compression and interlaminar shear) both dry and after exposure to hot/wet conditions. The laminates were also characterised for thickness variation, fibre volume fraction, degree-of-cure, glass transition temperature and acoustic impedance. These validations demonstrated that while significant improvements to property retention can be achieved for tensile loading conditions, certain compression conditions fail to achieve the same benefits. It was also found that a key aspect to implementing any perforation moulding technique lies in consistently achieving high quality hole definition to retain acoustic impedance performance. From the concept characterisation, a preliminary weight and detailed cost analysis were developed to assess the industrial feasibility for the method developed. This analysis showed that, with further investigation and the right application selection, the benefits of the novel approach could be realised.
A thesis submitted to the University of Plymouth
in partial fulfilment for the degree of
Master of Philosophy,
Department of Mechanical and Marine Engineering,
Faculty of Technology
2009-05-01T00:00:00ZThe Development of a Best Practice Framework for the Implementation of Advanced Manufacturing Technologies within Low-Technology-Enabled Small & Medium Enterprises
https://pearl.plymouth.ac.uk/handle/10026.2/2173
The Development of a Best Practice Framework for the Implementation of Advanced Manufacturing Technologies within Low-Technology-Enabled Small & Medium Enterprises
Lorraine, Rupert
In an increasingly challenging business climate, rapid developments in Advanced
Manufacturing Technologies (AMTs) such as 3D Computer Aided Design (3D CAD),
Computer Aided Manufacturing (CAM) and Computer Aided Engineering (CAE) create
new opportunities for innovative firms to capture market share, and spearhead new
directions and trends within their industrial sectors.
This exploratory study examines the challenges faced by Low-Technology-Enabled Small &
Medium Enterprises (LTESMEs), identifying the characterisations that contribute to poor
innovation performance and explaining how these can become manifested as barriers and
constraints to technology uptake. A best practice model is developed to enlighten and guide
decision makers in the implementation of AMTs - uncovering the underlying principles of
successful technology adoption / exploitation, and effective change management.
Linkages, such as the Knowledge Transfer Partnerships (KTP) scheme, are shown to
facilitate LTESME access to technology; transferring the pre-requisite knowledge and
expertise whilst mitigating the associated risks. A case study, comprising action research by
the author, documents the implementation of a 3D CAD/CAM/CAE system in a
traditional SME boatbuilding firm via a three-year KTP project.
Despite their inherent problems, SMEs are found to be ideally positioned to exploit AMTs,
provided they select an appropriate linkage - allowing them to match their needs to specific
technological capabilities. This investigation illuminates the subject area, providing a
framework for further study, whilst contributing to the growth and sustainability of SMEs.
2008-01-01T00:00:00Z