Mechanical System Design 2012
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Transcript of Mechanical System Design 2012
MBB4034
MECHANICAL SYSTEMS DESIGN
Associate Professor Dr Fakhruldin Mohd Hashim
1DrFMH© MBB4034-2012
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Imagine
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Learning Outcome
At the end of the course, you should be able to:1. Apply formal design techniques for energy/
automotive / manufacturing systems.2. Design energy/ automotive/ manufacturing systems
by applying standards and industrial practices, involving model formulation, design calculation, simulation, material and process selection, preparation of system configuration/ assembly designs and bills of materials.
3. Develop cost estimate of the project covering both the CAPEX and OPEX.
4. Produce technical and cost reports and present the reports orally.
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Assessment
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Progress Report – 20%Seminar / Tests – 20%Poster – 5%Final Report – 40%Oral Presentations & Viva-voce – 15%
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References
George E. Dieter, “Engineering Design - A Materials & Processing Approach”, 3rd edition, McGraw-Hill, 2000.
David G. Ullman, “The Mechanical Design Process”, 3rd edition, McGraw-Hill, 2003.
Karl T. Ulrich & Steven D. Eppinger, “Product Design & Development”, 3rd edition, McGraw-Hill, 2003.
Stuart Pugh, “Total Design”, Addison-Wesley, 1991.
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The Design Process
Descriptive models: “solution-focused” nature of
design thinking repeated evaluation cycle heuristic process
Prescriptive models: “problem-focused” nature of
design thinking more analytical work algorithmic process
Design is considered as a process of transforming perceived needs into a product or collection of products that meet these needs. Models of the design process can be categorized as either descriptive or prescriptive. More importantly it involves both analysis & synthesis activities.
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The Design Process Model
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FOCUSSED CHAPTERS
5
6
7
14
PROJECTENDS
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Terminologies
CONC-D is the process by which the design is initiated, carried to the point of creating a number of possible solutions, and narrowed down to a single best concept.
EMBO-D is the phase where a structured development of the chosen design concept takes place. Decisions pertaining to strength, material selection, size, shape and spatial compatibility are made in this phase.
CONF-D is the phase where the shape and general dimensions of components are established. Subsequently assembly, sub-assembly and parts are formalized.
DETAIL-D is the phase where the design is brought to a stage of a complete engineering description of a tested and producible product. Information pertaining to form, dimensions, tolerances, surface properties, materials, and manufacturing processes for each part & components are added. Detailed engineering drawings suitable for prototyping or manufacturing are prepared.
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Design Concept Generation
Creative MethodsMethods which are intended to help stimulate creative thinking. Such methods include: brainstorming synectics transformation counter-planning
Rational MethodsTechniques which encourage a systematic approach to design and incorporate methods which are relevant to certain stage(s) of the design process. Examples: morphology chart evaluation matrix
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Brainstorming
The Rules of Brainstorming Generate as many solutions as
possible – quantity counts Wild ideas are encouraged No criticism is allowed – defer
judgment till later
Brainstorming Methods Verbal
Speak out the ideas and list them down. Long explanation not allowed. Time limit: 30 min.
Written (“brainwriting”) Pin card method Method 6-3-5 Delphi method Mind mapping
Interactive Combined verbal & written Morphology chart Storyboard Synectics
Imagination is more important than knowledge, for knowledge is limited,
while imagination embraces the entire world
Albert Einstein
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Morphology Chart
A structured approach to the search for the solution to a complex or vague problem. It generates a large number of relationships
between related factors and elements of the problem, thus coming up with plausible solution ideas.
FEATURES MEANS (HOW)
POWER SOURCE Solar Hydrogen Natural gas
ENGINE TYPE Hybrid Linear Generator Electric
SUSPENSION Active Semi-active
Design of a futuristic car
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Evaluation Methods
Pugh EvaluationMatrix
Weighted ScoreMatrix
Benchmarking
Uses (+) ( - ) (S) scale
Weighted Rankx
Rating Score
Comparative studyagainst best-in-class
EUREKA!
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PUGH Evaluation MatrixAn approach to effectively evaluate concepts based on an agreed
set of criteria. The criteria are deduced from the design specificationand the analysis of needs. The evaluation is done based on the
comparison with a datum.
CRITERIA C1 C2 C3
SPEED PERFORMANCE D + + +
EASE OF MANUFACTURE A s + -
RELIABILITY T _ s +
Sum of ‘+’ U 1 2 2
Sum of ‘-’ M 1 0 1
Sum of ‘s’ 1 1 0
The winning concept is the one that has the highest difference between the ‘+’ and ‘- ‘. If there is a tie, then the one with the lowest ‘s’ is the winner
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Weighted Score Matrix
Also known as Decision Matrix: a decision-support tool allowing decision makers to solve their problem
by evaluating, rating, and comparing different alternatives on multiple criteria
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ALTERNATIVES
Option A Option B Option C
CRITERIA Weight Rating Score(1) Rating Score(1) Rating Score(1)
Criterion C1 1 3 3 3 3 3 3
Criterion C2 2 2 4 1 2 2 4
Criterion C3 3 1 3 3 9 2 6
Total 10 14 13
Scenario #1(1) Score = Rating * Weight
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Prototyping
A prototype is a scaled working model of the design, technically and visually complete. The purpose of the prototype is to confirm that the design satisfies all customer requirements and performance criteria. Prototype testing will give information about the reliability and robustness of the design, and also to verify whether environmental, safety and other requirement have been met.
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Dare to Innovate ?
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