13(2 2 0):
: :(Objective) , , , , , . : , , , , .:1. 2. , 3. 4. 5. - - -
-
1: , . . 2: , . .. ISO . . . 3: , 3-D . . 3-D , 4: , () . . . .
5: , . -. . . 6: , . . (, ..) . (, , , ..) . 7: , . . (, , ) . 8: ,
. . . . 9: , , , , , . . . . . 10: , . . . .:5%20%()3x25% = 75%
Grade:0 - 40F41 - 50 D51 - 55D+56 - 65C66 - 70C+71 - 75B76 80B+80
100A
:( ) ,
? - .- .
? WHAT IS MECHANICAL DESIGN?: , , .: may be defined as any
organized body of knowledge. : , , .WHAT IS MECHANICAL DESIGN? , ,
Albert EinsteinMechanicaldesign is creating new devices or
improving existing ones in an attempt to provide the best, or
optimum design consistent with the constraints of time,money, and
safety Imagination is more important than knowledge, for knowledge
is finite whereas imagination is infinite.Albert Einstein 99%
Genius is one percent inspiration and 99 percent perspiration
Thomas Ediso
?
DESIGN VS. ANALYSIS
DESIGN LEVELS(1) Adaptive design (2) Development design(3) New
design
DESIGN PROCESS
I. PROBLEM DESCRIPTION(1) . Recognize needs and set goals what
must be done to resolve the need.(2) - ()Perform market analysis
what is already available in the market and what they have to
offer.(3) ()-() ()/ Establish a function analysis need statement
and where the problem/need stands in the whole system(4) ()
Identify all specifications and constraints list of all pertinent
data and parameters that tend to control the design and guide it
toward the desired goal.
II. PRELIMINARY DESIGN(1) Various concepts for the system are
studied. (2) () Various subsystems are identified and their
preliminary designs estimated (Brainstorming).III. ANALYSIS(1) :
Evaluation of alternatives:Through a discussion and evaluation
process, the design is selected.(2) : () Analysis and
Optimization:Test the selected design against the physical laws.IV.
PROTOTYPE(1) / : (). Experiment and/or Testing The design on paper
is transformed into a physical reality.The iterative process has to
be continued until an acceptable system has evolved. V.
COMMUNICATION(1) - Marketing Selling the idea to management or the
client. ADAPTIVE DESIGN
DEVELOPMENT DESIGN
NEW DESIGN
:, . . , (Optimize) . 1. 2. ()(performance)3. ()4. 5. ()6. 7. 8.
9. 10. , 11. 12. 13. (Appearance) (attractive) , . :1. 2.(Sketch
Drawing), 3. (The free Body Diagram) .4. : , (Beam Deflection),
(Buckling of Column) .5. .6. , . , .7. .8. , .9. ().10.(), / (
).11. . , (), .
()
a. , , b. , c. , a. , b. , , c. , d. , .
1. 2. / / 3. 4. 5.
. Production Design Specification(PDS)
1. 2. . 3. 4. ()5. 6. 7. 8. 9. 10. 11. 12. , 13. .14. .15. 16.
17. 18. .19. 20. .21. 22. 23.24. EXAMPLE OF DR&O Hybrid Bicycle
Design
1., () Must be driven by electric motor, by human power or the
combination of both (as a consequence, it needs a one-way clutch at
the foot pedal).2. 250W The power of the electric motor must be
less than 250 Watt.3. , During braking the electric motor should be
off automatically.4. 50 km The battery must be able to store
electric energy for the distance of at least 50 km.5. 400 US$
Maximum target price is 400 US$. 6. 100,000 Production target is
100,000 bicycles per year.7. Attractive appearance since the target
consumers are mostly women.8. 25 kg Maximum target weight is 25 kg.
Automatic Hand-Brake Design :
1. Must function when the car stops. 2. Must not function when
the car runs. 3. Must have sufficient brake pressure on the sloping
road. 4. Must be able to release the hand-brake smoothly and once
released the car must not move backward on the sloping road. 5.
Should have a spare mechanic hand-brake in case the automatic brake
fails. 6. Should possess high reliability. 7. 1,000 US$/ The
additional cost for the automatic hand-brake system should be less
than 1,000 US$ per unit. 8. 10,000 / Expected production is 10,000
units per year. 9. Electronic system and sensors are expected to be
developed by other companies on a sharing cost basis. 10. 6 Should
be developed in less than 6 months. EVALUATION METHOD
, . , , : , : ,
PUGHDECISION MAKING OR PUGH METHOD1. () Choose or develop the
criteria for comparison. first method second method2. Select the
Alternatives to be compared.3. () Generate Scores.4. Compute the
total score.DECISION MAKING OR PUGH METHOD
(DESIGN IMPROVEMENT). , , , (well-liked) . , .EXAMPLE OF DESIGN
IMPROVEMENT
GANTT CHART . , :(1) Non-routine tasks,(2) / Distinct
start/finish dates,(3) (///)Resource constraints
(time/money/people/ equipment).: . . (, , )Tasks: are activities
which must be completed to achieve project goal. Break the project
into tasks and subtasks. Tasks have start and end points, are short
relative to the project and are significant (not going to library,
but rather, search literature).: . . -: , , Milestones: are
important checkpoints or interim goals for a project. Can be used
to catch scheduling problems early. Name by noun-verb form, e.g.
report due, parts ordered, prototype complete.
Steps in preparing a Gantt chart:1. () () List all events or
milestones in an ordered list, whenever possible.2. () ()Estimate
the time required to establish each event (remember it is an
estimate).3. () List the starting time and end time for each
event.4. Represent the information in a bar chart.
GENERAL REQUIREMENTS IN TECHNICAL WRITING1. Paper Type2.
Margins3. Print Requirements4. Line Spacing5. Language6. ()
Paragraphs and Sections7. , Caption for Figures, Tables and
Equations8. Quotations9. Footnotes10. Binding11. Miscellaneous12.
Ethical Issues
EXAMPLE OF CASE STUDYDesign of Water Pump
1. 2. 3. 4.5. 100,000 km Engineering Analysis :
25-40% 20-25% 40-50%
zu - (kJ/hour)B - (kg/hour)Hu - (kJ/kg)
bsp - (8 (g/kWh)Peff - (kWh)
ab = (kJ/hour)F = 0.25 m = ab /T .c m = (kg/hour) T = (oK) c =
(kJ/kgoK) Q = m / Q = (m3/hour) = (kg/m3), . , . . . . , . , . () .
()
Alternative Production of the Pump HousingCriteria Grey Cast
IronAl Die Casting
Strength Datum S
Weight Datum + + +
Cost Datum _
Assembly Datum +
Total Evaluation Better
Alternative Production of the Pump ImpellerCriteriaGrey Cast
IronAl Die CastingStamping
Strength Datum S +
Weight Datum + + + + +
Cost Datum _ +
Assembly Datum + +
Total Evaluation Better Best
(Detailed Drawing of the Pump Housing)
(Detailed Drawing of the Pump Impeller )
(Detailed Drawing of the Hub)
:1. 2. 3. 4. : 32H7 :
: : ; ; ; . , , : 15/09/2014Re: (322ME321)
(Title of the
Project)______________,______________________________________________
()(Project summary)
(Introduction)()(Problem descrition)()(Major
Assumption)()(Expected Outcomes)()(Budget
Summary)()(Conclusions)()
(), , , . . () . () . ()
ORAL PRESENTATIONS1. Analyze the Situation2. Planning Your
Presentation3. Self-Evaluation TestORAL PRESENTATIONS