1.0 engineering design 2 1314
DESCRIPTION
Engineering DesignTRANSCRIPT
Engineering Design
MOHD NAZIM ABDUL RAHMANSEMESTER 2 / 2013/2014
BMCD 25731
BMCD 2573|Engineering Design
Introduction to Engineering Design
Learning outcomes Characterize analysis problems and design
problems Explain how the form follows function are
interrelated Characterize five phases of design – design
process Describe product realization process Explain the economic life cycle of a product
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BMCD 2573|Engineering Design
What is Design, really?
Which of the following is design and which is analysis?
A. Given that the customer wishes to fasten together two steel plates, select appropriate sizes for the bolt, nut and washer.
B. Given the cross-section geometry of a new airplane wing we determine the lift it produces by conducting wind tunnel experiments.
Design Analysis
Form is the solution to a design problem.
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BMCD 2573|Engineering Design
How are Function and Form related
Design
controlholdmoveprotectstore
decision making processes
shapeconfigurationsizematerialsmanufacturing processes
Function
Form
Form Ever Follows FunctionLuis Sullivan
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BMCD 2573|Engineering Design
What is Design?
“to fashion after a plan” - Webster's dictionary
to design is to create something that has never been
although engineers are not the only people who design things
To design is to pull together / synthesis something new or to arrange existing things in a new way to satisfy a recognized need of society
Design – definition
Set of decision making processes and activities
to determine the form of an object,
given the customer’s desired function.
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BMCD 2573|Engineering Design
Design
Good design requires both analysis and synthesis
Understand how the part will perform in service Able to calculate expected behavior before it
exists in physical form by using the appropriate disciplines of science and engineering and the necessary computational tools – ANALYSIS
Identification of the design elements that will comprise the product into workable system - SYNTHESIS
Engineering Design Process
Starts with recognition of the need for the product.
Both design and redesign require knowledge of the intended use of the product, plus information on the Market Technical data Materials and production
For any product design you are part of a team!!!
Engineering Design Process contn’
Determine the need Starts with recognition of a need Sketching of the solution (product) is very
useful during this step. Establish known information
Includes gathering information on aspects of the products such as possible materials, market analysis, ability to manufacture, cost to manufacture, etc.
Engineering Design Process contn’ Stimulate Design Concepts
Consider the various aspects in the manufacture of the product such as material, shape, etc.
Investigate Design Concepts with Analytical Tools Use modern methods and tools to analyze
design alternatives.
Engineering Design Process contn’ Gather all information and review
Gather together all information and design alternatives and review so that decisions can be made.
Test the design that appears best. Accept, Modify, or Reject Optimize the design by iteration
Making Decisions? Use the design process
Establish functional requirementsDetermine constraintsSet performance targets
GeneratingAlternatives
FormulatingProblem
AnalyzingAlternatives
EvaluatingAlternatives
Create alternative forms(shape, configuration, size, materials, manufacturing processes)
all alternatives
feasible alternatives
Red
esig
nit
erat
ionDesign specifications
best alternative design candidateManufacturing specifications
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Example design problem - Stop a spinning shaft
(8 inch diameter, 1000 lbs, steel, 3000 rpm)
•Decide upon a satisfactory rate of deceleration •Determine the length of the shaft•Determine where it is supported•Determine what actuating energy is available•Decide to reverse engineer an existing product•Choose to research brakes in the library
“Formulation” Phase
Early in the design process, we decide upon the specifics of the function to be performed:
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BMCD 2573|Engineering Design
Decisions relating to concept?
•1. surface friction (e.g. drum brake, disk/caliper)
•2. opposing magnetic fields (e.g. inverse motor)
•3. air friction (e.g. fan blades)
Assume we decide on surface friction
Decide physical principles that will perform the function
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“Coneptual Design” Phase
Decisions on configuring products and new components?
Product configuration: disk/caliper, or drum, or band brake
location on shaft (right. left, middle) (Assume we decide on a disk/caliper brake) Part configuration:
relative size of hub to diskrelative size of rotor thickness to diameter
“Configuration Design” Phase
Decide upon product components & how they are arrangedDecide upon part features & how they are arranged
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1. rotor diameter (outer)2. rotor thickness3. brake pad width4. pad material5. hydraulic pressure on piston
Values for Parameters?
Decide upon specific values for design variables
“Parametric Design” Phase
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•machined rotor tolerances•pad bonding resin•assembly/testing procedure
Completing the details
“Detail Design” Phase
Decide upon the remaining manufacturing specifications
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Function ---- stop a spinning shaft
Final “Form” is the solution to a design problem
Form• rotor: 10 inch diameter, steel, 3/8-inch thick, cooling passages• forged steel caliper/housing • brake pads, 2 opposing, 4 sq. in., metal particles/epoxy matrix• steel piston,1-inch diameter, with elastomeric seals• 100 psi hydraulic piston pressure
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Design Phases
Formulation
Detail
Parametric
Configuration
Concept
Embodiment Design
Preliminary Design
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Design versus the Product Realization Process?
Industrial Design
Engineering Design
Production Design
Manufacturing(Production)
Distribution
Service Disposal
CustomerNeed
RealizedProduct
Sales / Marketing
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BMCD 2573|Engineering Design
Phases in the life of a product
Manufacture
Retire
Design
Use
establish functiondetermine form
fabricateassembledistribute
set upoperatemaintainrepair take down disassemble recycledispose
To satisfy the consumer…We must consider all the phases in the life of a product
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Inco
me
Inve
stm
ent
Introduction Growth Maturity Saturation Decline
Sales
Time
Product Development
Product realization begins the Product Life Cycle
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Types of Design
Original design - innovative design, It employs an original, innovative concept to achieve a need
Adaptive design - adapts a known ' solution to satisfy a different need to produce a novel application
Redesign - improve an existing design
Types of Design
Selection design - design task consists of selecting the components with the needed performance, quality, and cost from the catalogs of potential vendors
Industrial design - improving the appeal of a product to the human senses, especially its visual appeal, more artistic than engineering