Engineering Design - DSGN 221, for 2009 - 2010 |
Support Material - Extensive support material is available in the Stage 2 Design notes on the SoE web pages. Look on the Index to Online Documentation, then DSGN 215 / DSGN 221. Making use of these notes, applets and links should save you a lot of time.
2. Assignments
You should work in groups of 3 in all these assignments, each group will submit 1 report
for each assignment and normally all members will receive the same mark. BUT YOU MUST put a persons
name on the bottom of every page, to indicate who was primarily responsible for its
contents and writing.
NB:If difficulties do arise with group members not contributing, then
the module leader reserves the right to remove a group member(s) or require them to write and submit an
individual report or to give a lower mark (or zero) to the person(s) concerned.
i) Investigate the factors of safety of the key components of the
travelling crane in Brunel W6 - see attached details.
See also notes on stresses in a crane hook
Due in 11.00 pm on Monday 9th November 2009, ...
ii) - You will continue with this component in MECH 227 Select a component with reasonably simple geometry that you have access to (for measurement and 'estimation' of the material type and strength - some hardness testing will be necessary) and whose loading you can determine. You are to determine the maximum (or critical) stresses in the component. (In MECH 227 you need to develop and an FEA model of the component, run it and assess the results.) The report should explain simplifications, assumptions, loading and a discussion of results: eg.
iii) - One of the following - select then agree choice with module leader:
You must include a reasonable estimate of the cost of the manufactured system you select.
(A) Device to enable people in wheel chairs to use stairs
The usual way of providing for this is to add a system to the stairs which carries the wheelchair
and user. This system has the disadvantage that expensive conversions or additions, often
custom built, are needed for every flight of stairs.
A possible alternative is to design a
suitable attachment to a wheelchair to enable it to negotiate safely (almost) any stairs the user
encounters.
Your assignment is to select one of these alternative methods and design a such a system.
(B) Electric Office Stapler
Increasingly power assistance is being offered where previously it was 'normal' to use
non - power assisted operation. This has progressed most in automobiles, showing the scope for
this type of design, while leading to reduced the costs, sizes and increased reliability of motors
and other electrical and electronic components.
Some electrically operated staplers are already available, you should see what is currently
on the market and design a suitable competitive or complementary product.
(C) Power Assisted Tailgate Attachment for Cars
Modern cars have a lot of power operated systems - windows, sun roof, seats, steering. One
system which is only power operated / assisted in a few top of the range models
is the tailgate on estate / 5 door hatchbacks and many people find these heavy and
awkward to open and close.
For this assignment you are to design a system that can be added (probably by the dealer who supplies the new car)
to operate the tailgate of such a a vehicle.
You are required to produce a detailed design - your solution should include design layout,
sketches of key components, analysis of loads and stresses, specifications of bought in
items and costings.
Final assignment is due in 11.00am on Thursday 25th March 2010, ...
3. Advice About Writing Design Reports
Information is given in the DSGN 215 Design Notes
4. Marking Scheme
The marks for the three assignments are weighted as follows:
| Presentation | 10% |
| Analysis | 30% |
| Manufacturing and Materials | 30% |
| General Design - observations, ease of use, reliability, including discussion | 30% |
5. Lecture Programme
The 'Return to Module Introduction' links at the bottom of these pages will take you to the DSGN 215/221 module introduction, use the 'back' button on your browser to return to this page.
Note: The lecture programme may be varied somewhat according to student feedback, however the hand in dates for the assignments can not be changed - you should be aware that late submission of an assignment results in a zero mark unless you have valid extenuating circumstances.
1. Some reports were quite reasonable.
2. Most of the reports would have benefitted by better explanations, eg by
making use sketches to illustrate written descriptions.
3. Almost all groups lost marks because major decisions were made with no quantifiable
basis. Evaluation matrices should have been used.
4. In all reports the analysis could have been improved as there was insufficient analysis
carried out and that which was included was in many cases lacking in explanation.
Suggested Books - General Design:
Return to Online Documentation Index Page
David J Grieve, 13th October 2009.
1. ** 'Mechanical Engineering Design Notes - Theme: Automotive Engines', by David Grieve, 2008, ISBN: 978-0-9560037-0-6.
2. ** 'Mechanical Engineering Design', by J E Shigley and C R Mischke, 5th Ed., McGraw Hill.
3. 'Total Design', by S Pugh, Addison Wesley, 1991.
4. 'Case Studies in Engineering Design', by C Matthews, Arnold, 1998.
5. 'Mechanical Behaviour of Materials', by N E Dowling, Prentice - Hall, 1993.
6. 'Composites - Design Manual', by J A Quinn, J A Quinn Associates, Liverpool, L25 4SY, 2002.
7. ** 'Mechanical Design', by Peter R N Childs, Arnold, 1998.
8. 'Machine Elements in Mechanical Design', by R L Mott, Prentice - Hall Inc., 3rd ed. 1999.
9. 'Design of Machinery', by R L Norton, McGraw - Hill International Editions, 1999.
10. 'The Engineering Design Process', A Ertas and J C Jones, John Wiley and Sons, 1993.
11. 'Engineer's Toolkit - Engineering Ethics', by C Mitcham and R S Duvall, Prentice Hall, 2000.
Useful Reference:
12. 'Without Hot Air', by David J C MacKay, 2009. Free online: http://www.withouthotair.com. A lot of useful information on energy.
13. 'Roark's Formulas for Stress and Strain', by W C Young, 7th Ed. McGraw Hill.
** Indicates the text includes tables / charts from Raimondi and Boyd for plain bearing design.