In this unit students undertake an advanced engineering team project. During the projects, students will:
- work in groups of four to six, combining technical and commercial aspects in an industrial environment;
- grasp the essentials of an open-ended problem and apply a solution;
- organise their own work;
- integrate with the overall activities and direction of the team;
- communicate their work through a group technical report and group presentation.
Many projects are run in association with industrial companies, and arise from real company or user needs with team working and project management playing important roles. Aspects covered include:
- interpreting customer requirements;
- producing technical specifications;
- safety and evaluation of performance.
Communication skills are an important aspect to the course. Students will apply the knowledge and skills that they have acquired over their course including aspects of professional studies.
Example project: Improving the process of a residual stress measurement technique
All manufactured objects have internal/residual stresses and it is becoming increasingly important to know what these are as manufacturing tolerances are getting smaller due to industry striving to increase performance and efficiency.
The overall project aims to improve the process as well as the understanding of a residual stress measurement technique that has been developed here at Bristol. This technique is called Deep Hole Drilling (DHD) and is a semi destructive method that allows a specimen to be fully tested by only removing a small hole. This is advantageous as non destructive techniques only have a limited range and therefore cannot test larger samples where as destructive methods completely destroy the specimen being tested (as the name suggests).
The process works by drilling a reference hole and measuring its diameter accurately at several angles along the full length of the specimen. An electric spark process is then used to trepan around the reference hole, removing a core of material from the specimen. This, in theory, releases residual stresses and causes the original reference hole to distort. The change in the holes diameter is then used to calculate the residual stresses in the specimen using material theory.
The technique is being tested theoretically using Finite Element Analysis computer software (FEA) as well as experimentally in the lab. The use of the technique on non-axis-symmetric/non-uniform stress distributions is being tested to determine the accuracy and limitations of the process. Core extraction techniques that allow measurements to be taken without drilling and coring the full length of a specimen are also being tested to determine if accurate results can be achieved quicker.
As the technique utilises a tiny change in diameter, it is important that the technique is as accurate as possible, for this reason the sizes and ratios of the hole and core are being investigated as well as new techniques in aligning the electrode.
The image shows the first stage in the experimental process where the group were 'clocking' the specimen to ensure that it was correctly aligned with the machine bed that is used for the drilling, electrode machining and hole measurement. As the process relies on accuracy this is arguably the most important stage of the process as failing to set the specimen correctly would lead to inaccurate results.