Materials 1: Properties of Materials
Materials Selection Group Assignment
Lecturer: Dr M Peel (matthew.peel@bristol.ac.uk)
Teaching Associate: Dr G Horne (graeme.horne@bristol.ac.uk)
2014–2015

Intro
The 20 credit Materials 1 course is split into two equal sections, Properties of Materials and
Mechanics of Materials (Solid Mechanics), each worth 10 credits. This group assignment is worth 4% of Properties of Materials, i.e. 2% of Materials Engineering 2 or 0.4 credits.

Help
All questions related to all coursework, in the first instance, should be directed to the
Teaching Associate for the course, Dr Horne or, better yet, to the Piazza site for the course. An example materials selection document is provided on Blackboard. This should be used for reference but it is by no means a model answer. There are areas that could be improved upon, especially given the marking rubric. Use it to start a discussion in your group—what would you do better?

Goal
This assignment is a group project where you will attempt to select the best material(s) for a particular component. You will use the information from the lectures, additional reading and the CES Edupack software to accomplish this goal. You have been allocated, on Blackboard, into groups of 4-5 students roughly based on your tutor groups. Each group has been allocated a component to conduct their material selection process and prepare a short report together (Table 1). The mark will be given to the group as a whole. Report
The report should not be longer than 6 pages, but can be shorter. You will be marked on the quality of your content and not the number of pages but you will lose marks for going over the limit. It should not have more than 5 figures. The process of making your selection should follow a fairly predictable route and the report should follow a similar layout: Introduction: A careful description of the component you are analysing—do not assume the reader is familiar with its function. A diagram or picture will be very useful.
1

Table 1: Component allocation.
Component

Groups

Robotic arm on bomb disposal robot
1-8
Structural member in bionic leg
9-16
Automotive drive shaft
17-24
Bicycle seat post
25-32
Struts on a tower crane
33-40
Control cables in a light aircraft
41-48
Internal combustion engine connecting rod 49-56
Sailing yacht mast
57-62
Translation: Translate your component into functions, objectives, constraints and free variables. Carefully consider the precise situation the component will be used in.
There is not necessarily only one correct answer, it is about the justifications of your assumptions and simplifications. Initially you can afford to brain storm and include everything you can think of (to a degree). You then need to ruthlessly cut the list down to a few constraints and objectives you can reasonably handle and rank them by importance. Include the most pertinent constraint and objectives from your brain storm in the report. You don’t need to show everything but some examples of things that didn’t make it will reveal your thinking.
Screening: Screen out the failures by applying reasonable limits to your constraints.
This is clearly open to considerable interpretation but any reasonable estimates will be accepted. It may be challenging to set reasonable limits for parameters you are less familiar with. Consider looking at current or historical materials used and set these as starting points. If you make an important choice justify the values you select. Some bar/bubble plots from the CES software should be used to illustrate your point (but see below).
Ranking: Rank the remaining materials by creating relevant material indices. You will probably need to make some considerable simplifications to arrive at a model. This is fine—but justify your choices. A selection of equations are available on blackboard for you to use.
Discussion and conclusions: It is entirely possible you may arrive at the same choice of material as is currently used. This is