IDENT
OPP
GATHER
INFO
DEFINE
PROBLEM
GEN
CONCEPTS
SCREEN
CONCEPTS
IMPLEMENT
Evaluating Your Design
How to determine if you got it right
1. Sit with your team
2. Team takes 10 index cards
before lecture starts
37
ME 4054 Design Projects
HANDOFF
Take-Home Message
A good design is one
where test results
prove that it meets
the requirements
$30 for students, register at the door
www.dmd.umn.edu
Exercises
• As a team, you will be completing exercises
• For each
– Work as a team
– Write your final response on an index card
– You may be giving the card to another team for
assessment
Why Prototype in ME 4054?
A. To conduct engineering tests
B. To communicate with the customer
C. To have something to show at the Design
Show
D. To reduce technical risk
As a team, write answer on index card.
You may select one or more of the
choices
ALL KINDS OF PROTOTYPES
• Anything and everything can be
called a prototype
–
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–
–
–
–
–
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Sketch
Carved foam
Creo rendering
ANSYS simulation
Bread board
Double (or half) scale
PowerPoint UI
Functional/non-functional
Engineering model
Display model
Analytical
Focused
Comprehensive
Physical
Virtual Prototyping
Evaluation in the Design Process
IDENT
OPP
GATHER INFO
DEFINE
PROBLEM
GEN CONCEPTS
Return to the design
SCREEN
CONCEPTS
IMPLEMENT
requirements
HANDOFF
Product Design Specification
Planning the Prototype
Define
Purpose
• Learning needs (engineering)
• Communication needs (boss, customer)
Establish
Level
• Works-like/Looks-like
• Physical/Virtual
Create Test
Plan
Create
Schedule
• Evaluate by testing
• Design
• Fabricate
• Evaluate
Exercise
For your next (or current)
prototype, describe three
engineering performance
features you plan to test
Key Dates For Prototype
1
•Ready to assemble
2
•Ready to test
3
•Test results complete
Exercise
For your next (or current)
prototype, list 3 dates:
1.Ready to assemble
2.Ready to test
3.Test results delivered
Product
Prototype
Examples from draft design report
1. Objective
2. Method
3. Data Analysis
Every metric in the list of design
requirements, must have a
related test plan
Exercise
Write a test plan to
evaluate, using your
prototype, one engineering
requirement of your design
1. Objective
2. Methods
3. Data Analysis
Physical Test
Simulation
Test
Engineering
FEM
• Output
• Strength
• Cyclic fatigue
• Acceleration response
• Weight
• Size
• Stress
• Deflection
• Temperature
• Flow
Dynamics
Use
• Step response
• Frequency response
• Natural frequency
• Time of procedure
• Fit
• Instructions
Kinematics
• Motion
• Interference
Example:
Simulation of Manufacturing Line
Simulation of one station
Build Test Apparatus and Evaluate
Additional Methods for Evaluation
• Sensitivity Analysis: how sensitive is your design if a
key parameter is not closely specified?
• Design of Experiments: Finding an optimum set of
processing conditions (see book by George Box, Design
and Analysis of Experiments)
• Statistical Process Control: In a manufacturing
process what is the range of variability that can be
expected? (D&M I manufacturing text has overview)
• Measurement Error Analysis (Measurements lab)
How to get an A if you have a physical prototype