1. Introduction
Good written submissions will be a key to achieving high marks, but this does not mean long reports. I would expect a good report to contain perhaps about 6000 words plus extensive well labelled diagrams and calculations with careful explanations and appendices. Reports must be word processed, a basic word processor (where equations and diagrams are added by hand) will be quite satisfactory. Report pages must be numbered, but this can be done by hand. Carefully labelled sketches must be used to assist in the explanation of calculations.
We are looking for evidence that you have a good understanding of the work that you have carried out. For this reason, if you are designing a sub-assembly containing several components, rather than do superficial analysis of all the components, you will get better marks by providing a detailed analysis of perhaps only one or two components together with full information about the materials selection, processing and cost estimates.
You are strongly advised to ask a friend to read through your work before it is submitted to help you avoid careless errors, poor grammar etc. For group design assignments where different people may have written each section, the person responsible for assembling the report - normally the group chair - should read all sections to check there are no contradictory statements, no omissions and that everything is clear. It is important that sufficient time is allowed for this when you are planning your work. Writing up and editing always seem to take longer than you initially thought.
2. An Example of Good and bad Descriptions of Materials and Processing Requirements
If local loading could cause indentation, you might previously have said the component was to be made from 'case hardened steel'. This design / manufacturing / materials specification is worth about 5 % !
To gain a high mark you need to specify the steel, BS or ASTM etc. number, the depth of case (total and possibly the fully hard depth) and core hardness / tensile strength, how the part is to be carburised and how it is to be hardened, eg austenitising times and temperatures, method of quenching (oil, polymer solution or water) temper time and temperature. This degree of detail is NOT required for every component, you should select a small number of components such safety critical parts or parts that are critical to the performance of the product and go into detail with them to demonstrate your knowledge and understanding.
3. How to Obtain Good Marks for Design Calculations
Reports must include samples of appropriate design calculations, including the assumptions these were based on, references to National Standards and other sources of information and data that have been used. You should note that some of the design work involves repetitive work / complex analysis and extra marks will be gained for appropriate use of spreadsheets, mechanism analysis packages and finite element analysis.
Normally design calculations should have:
4. Other Points
In many countries, national (and increasingly international) standards apply to large numbers of products. At an early stage in the work you should check for the existence of any standards that might apply.
Any drawings you submit to describe parts should be good quality, carefully labeled sketches (or CAD drawings if you prefer). Do NOT use valuable time doing formal drawings where they are not called for. There will be no formal teaching of how to use the CAD system.
Do NOT make the mistake of writing a miniature text book on materials or manufacturing. You must explain why you have selected the materials and manufacturing processes that you have chosen for YOUR proposed design.
You should keep in mind that some of the components may be operating in corrosive environments, at high temperatures as additional
heating will occur due to higher output and losses so systems and components may well need to be designed so that adequate cooling
occurs.
Many parts will be subjected to cyclic loading so the fatigue strength of critical components will need to
be considered. You should keep in mind that we seldom have accurate knowledge of the loading on a
system and the properties of the materials used will have a statistical spread. Your design report
should explain the assumptions you have made about these matters.
NB It is acceptable for you to include copied diagrams and tables in your reports, but you MUST include full reference to the original. In the case of a web address include the date and time it was accessed. Failure to do this may well be considered to be plagiarism, which attracts heavy penalties, see the University Regulations.
5. Notes on Assessment
You should note that if the presentation is so poor that we are not able to understand some of your design or calculations, then more than 10% of marks may be lost. You should note that 1 mistake does NOT equate to 1 mark lost. A minor mistake may well not result in any marks lost, however 1 major mistake which shows serious lack of understanding, gross carelessness, eg absurd values being proposed, may result in the loss of several marks.
One of the aims of this module is to provide you with an introduction to design as an open ended subject. In many cases there is no single 'correct' solution - two very different designs might be equally good. Consequently it is not possible at the outset to give a detailed marking scheme, the assessor must use his / her professional judgement when assessing your work.
In many cases you will have to make assumptions, using your judgement, because other aspects of the design have not yet been completed. Provided you give some good reasons why you made such assumptions, you will be given credit if you later in the year report that on the basis of more recent work, an earlier assumption was not correct.
As there is group work in this module, inevitably not all tasks are equally difficult. Students who have a simple piece of work will have to complete it rigorously and with few mistakes to get as good a mark as a student who makes a reasonable job of a much more complicated part of an assignment.
General information about the type of work expected for various grades of mark can be found in the student handbook, if you are not familiar with this, you should look at it in the near future.
6. Support Available for Assignment
There is no formal lecture program for the final year Engineering Design, DSGN 313, module, information about the design of machine elements can be found on DMME 2nd year design notes (DSGN 215 / DSGN 221). These notes should be your starting point for most searches for guidance and information
The Index to Online Documentation contains links to modules / courses on a number of other subject areas. Some links in the notes are to external sites. A list of useful reference is situated at the bottom of this page. Theory and examples on stress analysis can be found on the Mississippi State University pages. Click on 'Classes' then on the 'Tutorial Page of Aerospace Structures'. Some further information about the design of machine elements can be found on the Mechanical Engineering Department pages at the University of Western Australia.
There are a number of 'Calculators' included in the year 2 design notes DSGN 215 / 221 which enable you to type in values (in the units stated) click on the 'Calculate' button and see the answer. Any value(s) can be changed and when the 'Calculate' button is clicked, the new result is displayed. There are some 'interactive plots' provided, again values in the appropriate units are typed in and when the 'calculate' button is clicked, a plot is drawn displaying relevant information. In some cases changing one or more values and clicking on 'Calculate' updates the plot. Please note these plots are done with Java Applets which require Netscape 4.5 or later or IE4 or later to run. These are designed to help you, it is foolish not to make full use of them.
Return to assignment introduction
David J Grieve, 14th September 2006, (previously: 17th June 2003).