Faculty of Engineering (University of Bristol)
National Composites Centre, Bristol (BS16 7FS)
Preforming is an important step in the manufacturing of polymer composites as it affects quality, cost as well as throughput of the entire manufacturing process. Ability to manufacture high volume/value preforms, repeatedly and reliably, is the need of the hour in many composites applications in aerospace and automotive sectors. Robotics and automation are key to developing cost-effective, high volume preforming processes. While this means reduced possibility to introduce human errors, it also gives less opportunities for remedial human intervention, in case of any issues during manufacturing. As a result, virtual manufacturing via process simulations as well as detailed understanding of material characteristics becomes essential. This project is aimed at these two requirements.
In general, the preform is made from multiple fabric plies, all stacked together by robots using automatic grippers and end-effectors. The stack is then formed into the desired shape using one of the candidate processes, such as stamping. Almost all of these processes involve application of heat and/or pressure. Once formed, the entire stack, again needs to handled using robots, grippers and end-effectors, to transfer it to the next manufacturing or storing station. To ensure integrity of the stack throughout the preforming process and to retain the formed shape, a binder or a veil, already on the plies, is activated. Depending on multitude of parameter such as the nature of the geometry, process speed, etc., the stack may experience complex loading, involving shear, bending, friction and tension during all of these steps. On the other hand, current understanding of the material characteristics is limited to pure loading modes, mainly in shear, bending and tension and at room temperatures. Therefore, there is an urgent need to enhance the fundamental understanding of the material characteristics, especially at elevated temperatures commensurate with preforming processes, if one were to be able to realise increased usage of automation and robotics in preform manufacturing.
The project aims to undertake material characterisation studies at high temperatures involving complex loading of textile reinforcements. A key aspect of the project is to develop a new, low-cost set-up that allows materials characterisation at elevated temperatures of up to 100 0C. Using this new set-up, a number of materials will be tested to develop models that describe the material behaviour at various temperatures. These models will then be used in process simulations to improve the accuracy of simulation models. The main activities to be undertaken during the first twelve months will include:
1. Drawing up systems requirements for the new set-up, populating and grading of candidate solutions to identify optimum solution under cost-quality constraints
2. Creating, and finalising the design of the set-up
3. Manufacturing, integration and testing of the set-up with electronics, etc., through internal/external suppliers
4. Identification of important process parameters to be tested (through quick literature review & consultation with peers etc.) and creation of DOE matrix
5. Testing of different materials according to the DOE matrix
6. Collection, analysis and data mining to gain deep insights into the material behavior
7. Use of new material models in forming simulation tools (e.g. Abaqus, PAM-FORM etc.) to improvise existing models
8. Preparation of project reports, presentations etc. and/or presenting to internal/external audience including project sponsors, Tier 1/2 partners etc.
PLEASE NOTE: Applications are considered as soon as they are received, and the position will be allocated as soon as a suitable candidate is found.
How to apply: If you are interested in applying for this EngD project please send your CV, covering letter and academic transcript to [email protected]
About the IDC and the EngD programme:
For further information about the IDC and the EngD programme please visit: http://www.cimcomp.ac.uk/idc