CHAPTER 3
Introduction to Engineering Design
© 2011 Cengage Learning Engineering. All Rights Reserved.
3-1
Engineering – An Exciting Profession
• Introduction to engineering profession
• Preparing for an engineering career
• Introduction to engineering design
• Engineering communication
• Engineering Ethics
© 2011 Cengage Learning Engineering. All Rights Reserved.
3-2
Outline
In this chapter we will
• Introduce you to the engineering design
process
• Discuss the basic steps that most engineers
follow when designing a product
• Discuss the importance of considering
sustainability in design
© 2011 Cengage Learning Engineering. All Rights Reserved.
3-3
Outline (continued)
• Introduce important design factors such as
 Economic consideration
 Material selection
 Teamwork
 Project scheduling
 Engineering standards and codes
• Present cases studies in civil, mechanical/
electrical engineering
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3-4
Objectives
The main objective of this chapter is:
To introduce the steps engineers follow to
successfully design products or provide
services that we use in our everyday lives
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3-5
Design Process – Basic Steps
1. Recognizing the need for a product or a service
2. Problem definition and understanding
3. Research and preparation
4. Conceptualization
5. Synthesis
6. Evaluation
7. Optimization
8. Presentation
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Design Process – Basic Steps (continued)
Step 1: Recognizing the need for a product
or a service
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3-7
Design Process – Basic Steps (continued)
Step 2: Problem definition and understanding
• This is the most important step in any design
process
• Before you move on to the next step
 Make sure you understand the problem
 Make sure that the problem is well defined
• Good problem solvers are those who first fully
understand what the problem is
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3-8
Design Process – Basic Steps (continued)
Step 3: Research and preparation
• Collect useful information
 Search to determine if a product already exists
 Perhaps you could adopt or modify existing
components
 Review and organize the information collected in a
suitable manner
Step 4: Conceptualization
Generate ideas or concepts that could offer
reasonable solutions to your problem
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3-9
Design Process – Basic Steps (continued)
Step 5: Synthesis
• At this point you begin to consider details
• Perform calculations, run computer models,
narrow down the type of materials to be used, size
the components of the system, and answer
questions about how the product is going to be
fabricated
• Consult pertinent codes and standards for
compliance
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3-10
Design Process – Basic Steps (continued)
Step 6: Evaluation
• Analyze the problem in more
detail
• Identify critical design
parameters and consider their
influence in your final design
• Make sure that all calculations
are performed correctly
• Best solution must be
identified from alternatives
© 2011 Cengage Learning Engineering. All Rights Reserved.
• Details of design
must be worked out
fully
3-11
Design Process – Basic Steps (continued)
Step 7: Optimization – minimization or maximization
• Optimization is based on some particular criterion
such as cost, strength, size, weight, reliability,
noise, or performance.
• Optimizing individual components of an
engineering system does not necessarily lead to
an optimized system
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3-12
Design Process – Basic Steps (continued)
An optimization
procedure
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3-13
Design Process – Basic Steps (continued)
Step 8: Presentation
• You need to communicate your solution to the
client, who may be your boss, another group
within your company, or an outside customer
• Engineers are required to give oral and
progress reports on regular basis to various
groups, consequently presentation could well
be an integral part of many other design steps
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3-14
Design Process – Basic Steps (continued)
Step 8: Presentation
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3-15
Example 3.1 – Optimization
Given:
To purchase storage tanks with a budget of $1680.
Available floor space is 90 ft2
Manufacturer A:
16 ft3 capacity @ $120 each, requires 7.5 ft2 floor space
Manufacturer B:
24 ft3 capacity @ $240 each, requires 10 ft2 floor space
Find:
Greatest storage capacity within the budgetary and floorspace limitation
© 2011 Cengage Learning Engineering. All Rights Reserved.
3-16
Example 3.1 – Optimization
Solution:
Let x1 = 16 ft3 capacity and x2 = 24 ft3 capacity. Then the objective function Z
we wish to maximize becomes
maximize Z  16 x1  24 x2
subject to the following constraint s :
120 x1  240 x2  1680
7.5 x1  10 x2  90
x1  0
x2  0
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3-17
Example 3.1 – Optimization
120 x1  240 x2  1680
Region as given by linear
inequality
© 2011 Cengage Learning Engineering. All Rights Reserved.
Feasible solution
3-18
Civil Engineering Design Process
• Civil engineering design process is slightly different
from other disciplines
• Civil engineering is concerned with providing public
infrastructures and services such as the design and
construction of

Buildings
Bridges
Tunnels

Airports

Sewage systems


© 2011 Cengage Learning Engineering. All Rights Reserved.

Roads and highways
Dams
Mass transit systems

Water supply systems


3-19
Civil Engineering Design Process (continued)
• Civil Engineers must follow specific procedures,
regulations, and standards that are established by
local, state, or federal agencies
• For example, design procedures for a bridge will be
different than for a building or a mass transit system
© 2011 Cengage Learning Engineering. All Rights Reserved.
3-20
Civil Engineering Design Process (continued)
• Design process for buildings:
1. Recognizing the need for a building
(similar to previous step 1 for other engineering disciplines)
2. Define the usage of the building
(similar to previous step 2: problem definition and understanding)
3. Project planning
(similar to previous step 3: research and preparation)
4. Schematic design phase
(similar to previous steps 4 & 8: conceptualization and presentation)
5. Design development phase
(similar to previous steps 5, 6 & 8: synthesis, evaluation, and presentation)
6. Construction documentation phase
(similar to previous steps 5 & 7: synthesis and optimization)
7. Construction administration phase
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Design Process for Buildings
Step 1: Recognizing the need for a building
• For example: build a new elementary school or
expand existing one to accommodate the increase in
children’s ages between 6 and 12, or
• Build a new medical clinic due to an increase in
medical needs and convenience to patients, or
• Replace or expand factory to increase production due
to market demand, or
• Build, replace, or expand bridge due to increase in
traffic volume
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Design Process for Buildings (continued)
Step 1: Recognizing the need for a building
(continued)
• In private sector
 The need is usually identified by the owners of a
business or real estate
• In public sector
 The need is usually identified by others, such as a
school principal, a city engineer, or a district engineer
 The need must be approved by corresponding
oversight body, such as a school board, city council,
or the department of transportation and state
legislation
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Design Process for Buildings (continued)
Step 2: Define the usage of the building
• Owner (client) determines types of activities that would
take place in the building
 New elementary school: principal forecasts the
number of students enrolled in the future; determines
the number of classrooms and computer labs, and the
need for a library or a cafeteria
 Medical clinic: staff determine number of examination
rooms, x-ray labs, reception areas, record rooms, and
so on
• The usage will help architect determine the amount of area
that would be required
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Design Process for Buildings (continued)
Step 3: Project planning
• Client selects potential sites for the new building
• Factors influence site selection:
 Cost and location
 Zoning
 Environmental impact
 Archaeology impact
 Traffic flow
• Client selects an architect firm or a contractor to initiate
the design phase
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Design Process for Buildings (continued)
Step 4: Schematic design phase
• Architect consults with client to fully understand the
intended usage of the building and to obtain approximate
budget for the project
• Architect prepares multiple schematic designs for the
building
• Client and architect narrow down the options to one or
two designs
• Schematic design includes: material type, framing
system, and layout of rooms and spaces
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3-26
Design Process for Buildings (continued)
Step 5: Design development (DD) phase
• Architect continues to finalize layout of the building
• Architect consults with a structural engineer to
determine the limits of column size and beam size
• The structural engineer then performs a preliminary
design for the building
• The mechanical engineer performs the preliminary
design for the HVAC system
• The electrical engineer performs the preliminary
electrical design
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Design Process for Buildings (continued)
Step 5: Design development (DD) phase (continued)
• The interior designer performs a preliminary design for
the interior of the building
• The contractor provides a cost estimate for the project
• The architect meets with the client to present the
preliminary design and seek feedback
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Design Process for Buildings (continued)
Step 6: Construction documentation (CD) phase
• All the detail work is done in this phase
• Construction document includes
 Design specification and drawings from the
architect, civil, structural, mechanical, and
electrical engineers, and the interior designers
 Work of landscape architect may be included
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3-29
Design Process for Buildings (continued)
Step 6: Construction documentation (CD) phase
(continued)
• Civil engineer provides site plan design which includes:
 Grading of the ground from the perimeter of
building to sidewalk
 Grading of the parking area
 Drainage for surface runoff
 Demolition plan and the relocation of power-lines
as needed
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3-30
Design Process for Buildings (continued)
Step 6: Construction documentation (CD) phase
(continued)
• Structural engineer provides all the design details for
structural components including:
 Foundation, beams and columns, interior and exterior
walls, and connections
 Roof and floor supports and supports for opening such
as windows, doors
 Canopies ……..
• Structural engineer must bear in mind all the design
specifications required by the building codes as established
by local government
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Design Process for Buildings (continued)
Step 6: Construction documentation (CD) phase
(continued)
• Construction document must be reviewed and
approved by the building inspectors
• If the client has not selected a contractor, as it is
common for publicly funded projects, interested
contractors would purchase a hard copy of the
construction document or download it from the
architect’s web site for bid preparation
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Design Process for Buildings (continued)
Step 6: Construction documentation (CD) phase
(continued)
An example of design detail included in a construction document
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Design Process for Buildings (continued)
Step 7: Construction administration phase
• Contractor will have a superintendent on site to
manage the construction and its progress and
coordinates all the subcontractors
• Project manager representing the architect would meet
with the site superintendent and the client on a regular
basis to review the construction progress and to any
issues that require further attention
• Structural engineer visits the construction site
periodically to observe the progress of the project
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Design Process for Buildings (continued)
Step 7: Construction administration phase
(continued)
• Structural engineer is responsible for reviewing the
shop drawings submitted by the fabricators through the
general contractor
• When the project is completed, the project manager
will walk through the building with the client and the
superintendent to go through a “punch” list
• The building must be approved by the building
inspector prior to being occupied
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Other Engineering Design Considerations
• Engineering economics
• Material selection
• Teamwork
• Conflicts Resolution
• Project scheduling and task chart
• Evaluating alternatives
• Patent, trademark, and copyright
• Engineering standards and codes
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3-36
More in
Chapter
20
Engineering Economics
• Economic factors always play important roles
in engineering design decision making
• Products that are too expensive cannot be
sold at a price that consumers can afford and
still be profitable to the company
• Products must be designed to provide
services not only to make our lives better but
also to make profits for the manufacturer
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Material Selection
Selection of material is an important design decision
• Examples of properties to consider when selecting
materials
 Density
 Ultimate strength
 Flexibility
 Machinability
 Durability
 Thermal expansion
 Electrical & thermal conductivity
 Resistance to corrosion
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3-38
Material Selection (continued)
• Examples of questions design engineers may
ask when selecting materials
 How strong will the material be when
subjected to an expected load?
 Would it fail, and if not, how safely would
the material carry the load?
 How would the material behave if its
temperature were changed?
 Would the material remain as strong as it
would under normal conditions if its
temperature is increased?
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Material Selection (continued)








How much would the material expand when its
temperature is increased?
How heavy and flexible is the material?
What are its energy absorbing properties?
Would the material corrode?
How would it react in the presence of some
chemicals?
How expensive is the material?
Would it dissipate heat effectively?
Would the material act as a conductor or as an
insulator to the flow of electricity?
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Material Selection (continued)
More in
chapter 17
• Other application specific questions to be considered:
for example, for bioengineering applications
 Is the material toxic to the body?
 Can the material be sterilized?
 When the material comes into contact with body
fluid will it corrode or deteriorate?
 How would material react to mechanical shock
and fatigue?
 Are the mechanical properties of the implant
material compatible with those of bone to ensure
appropriate stress distributions at contact surface
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3-41
Material Properties (continued)
• Material properties depend on many factors
 How the material was processed
 Its age
 Its exact chemical composition
 Any nonhomogenity or defect within the material
• Change with temperature and time as the material
ages
• In practice, you use property values provided by the
manufacturer for design; textbook values are typical
values
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3-42
Material Properties (continued)
• Electrical resistivity
 Measure of resistance of material to flow
of electricity
 Plastics and ceramics typically have high
resistivity
 Metal typically has low resistivity
 Silver and copper are one of the best
conductors of electricity
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Material Properties (continued)
• Density
 Defined as mass per unit volume
 Measure of how compact the material is
for a given volume
 Average density of
• aluminum alloys = 2700 kg/m3
• steel = 7850 kg/m3
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3-44
Material Properties (continued)
• Modulus of elasticity (Young’s modulus)
 Measure of how easily a material will
stretch when pulled
 Measure of how well material will shorten
when pushed
 The larger the modulus of elasticity, the
larger the force required to stretch or
shorten a piece of material
 Modulus of elasticity for
• aluminum alloy = 70 to 90 GPa
• steel = 190 to 210 GPa
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3-45
Material Properties (continued)
• Modulus of rigidity (shear modulus)
 Measure how easily a material can be
twisted or sheared
 Value of shear modulus shows the
resistance of a given material to shear
deformation
 Shear modulus for
• aluminum alloys = 26 to 36 GPa
• steel = 75 to 80 GPa
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3-46
Material Properties (continued)
• Tensile strength
 Determined by measuring the maximum
tensile load a material specimen in the
shape of a rectangular bar or cylinder can
carry without failure
 Tensile strength or ultimate strength is
expressed as the maximum tensile force
per unit cross-sectional area of the
specimen
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3-47
Tensile Test of Metal Specimen
Tensile test set up
Original
specimen
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Final
specimen
10-48
Material Properties (continued)
• Compressive strength
 Is determined by measuring the maximum
compressive load a material specimen in
the shape of a rectangular bar, cylinder, or
cube can carry without failure
 Is expressed in force per unit crosssectional area of specimen
 In concrete ranges between 10 to 70 MPa
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10-49
Material Properties (continued)
• Modulus of resilience
 Mechanical property that shows how
effective the material is in absorbing
mechanical energy without going through
any permanent damage
• Modulus of toughness
 Mechanical property that indicates the
ability of the material to handle
overloading before it fractures
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10-50
Material Properties (continued)
• Strength-to-weight ratio
 Ratio of strength of the material to its
specific weight
 Either tensile strength value or yield
strength value can be used to determine
the ratio
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10-51
Material Properties (continued)
• Thermal expansion
 Shows the change in the length of a
material that would occur if the
temperature of the material were changed
 Important material property to consider
when designing products and structures
that are expected to experience a
relatively large temperature swing during
their service lives
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10-52
Material Properties (continued)
Thermal conductivity
Shows how good a material is in
transferring thermal energy (heat) from a
high temperature region to a low
temperature region within the material
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10-53
Material Properties (continued)
• Heat capacity
 Represents the amount of thermal energy
required to raise the temperature of 1 kg
mass of material by 1oC, or 1 lb-mass of
material by 1oF
 Materials with large heat capacity values
are good at storing thermal energy
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10-54
Material Properties (continued)
• Viscosity
 Fluid property that measures how easily a
given fluid can flow
 The higher the viscosity value is, the more
resistance the fluid will offer to flow
 For example, less energy is needed to
transport water in a pipe than to transport
motor oil or glycerin
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10-55
Material Properties (continued)
• Vapor pressure
 Under the same conditions, fluids with low
vapor-pressure values will not evaporate
as quickly as those with high values of
vapor pressure
 For example, water has a higher vapor
pressure value than glycerin
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10-56
Material Properties (continued)
• Bulk modulus of compressibility
 Measures how compressible a fluid is
 Represents how easily can one reduce the
volume of fluid when the fluid pressure is
increased
9
2
 For example, it would take 2.24x10 N/m
of pressure to reduce 1 m3 of water to
0.99 m3, a change of 1%
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10-57
Teamwork
• Design team
a group of individuals with complementary
expertise, problem solving skills, and
talent who are working together to solve a
problem or achieve a common goal
• Employers are looking for individuals who not
only have a good grasp of engineering
fundamentals but who can also work well with
others in a team environment
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Common Traits of Good Teams
Successful teams have the following
components:
• The project that is assigned to a team must
have clear and realistic goals. These goals
must be understood and accepted by all
members of the team.
• The team should be made up of individuals
with complementary expertise, problem
solving skills, background, and talent.
• The team must have a good leader
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3-59
Common Traits of Good Teams (continued)
• The team leadership and the environment in
which discussions take place should promote
openness, respect, and honesty.
• The team goals and needs should come
before individual goals and needs.
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3-60
Secondary Roles of Good Team
Members
• The Organizer – experienced and confident;
trusted by members of the team and serves as a
coordinator for the entire project
• The Creator – good at coming up with new ideas,
sharing them with other team members, and
letting the team develop the ideas further
• The Gatherer – enthusiastic and good at
obtaining things, looking for possibilities, and
developing contacts
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3-61
Secondary Roles of Good Team
Members (continued)
• The Motivator – energetic, confident, and
outgoing; good at finding ways around
obstacles
• The Evaluator – intelligent and capable of
understanding the complete scope of the
project; good at judging outcomes correctly
• The Team Worker – tries to get everyone to
come together, does not like friction or
problems among team members
© 2011 Cengage Learning Engineering. All Rights Reserved.
3-62
Secondary Role of Good Team
Members (continued)
• The Solver – reliable and decisive and can
turn concepts into practical solution
• The Finisher – can be counted on to finish his
or her assigned task on time; detail oriented
and may worry about the team’s progress
toward finishing the assignment
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Other Factors Influencing Team
Performance
• The way a company is organized
• How projects are assigned
• What resources are available to a team to
perform their tasks
• Corporate culture: whether openness,
honesty, and respect are promoted
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Conflicts
When a group of people work together, conflicts
sometimes arise. Conflicts could be the result of
• Miscommunication
• Personality differences
• The way events and actions are interpreted by
a member of a team
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Conflict Resolution
• Managing conflicts is an important part of a
team dynamic
• In managing conflicts, it is important to
recognize there are three types of people:
 Accommodating
 Compromising
 Collaborative
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3-66
Conflict Resolution – Type of People
• Accommodating team members - avoid
conflicts
 Allow assertive individuals to dominate
 Making progress as a whole difficult
 Could lead to poor team decision
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3-67
Conflict Resolution – Type of People
• Compromising team members
Demonstrate moderate level of
assertiveness and cooperation. By
compromising, the team may have
sacrificed the best solution for the sake of
group unity
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Conflict Resolution
• Collaborative Conflict Resolution Approach
 High level of assertiveness and
cooperation by the team
 No finger pointing
 Team proposes solutions
 Means of evaluation
 Combine solutions to reach an ideal
solution
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Project Scheduling and Task Chart
A process that engineering managers use to ensure that a project
is completed on time and within the allocated budget
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Evaluating Alternatives
• When a design is
narrowed down to a
few workable concepts,
evaluation of these
concepts is needed
before detail design is
pursued
An Example of evaluation worksheet
• Each design would
have its own evaluation
criteria
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3-71
Patent, Trademark, and Copyright
• Patent, trademark, service marks, and
copyrights provide a mean to promote new
ideas and inventions and at the same time to
protect the inventors’ intellectual properties
• These are examples of means by which
intellectual property is protected by the U.S.
laws
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Patent
• The right to exclude others from making, using,
offering for sale, or selling the invention in U.S. or
importing the invention into U.S.
• Does not grant the inventor the right to make, use, or
sell the invention, it excludes others for doing so
• New patent is protected for 20 years from the date the
patent application is filed
• Design patent is good for 14 years from the time it
was granted
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Patent (continued)
• Utility patent lasts for either 17 years from the time it
was granted or 20 years from the earliest filing date,
whichever is longer
• A utility patent is issued for the way an item works
• A design patent protects the way an item looks
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Trademark
• Trademark is a name, word, or symbol that a
company uses to distinguish its products from
others
• Excludes others from using the same or
similar mark
• It does not prevent others from making the
same or similar products
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3-75
Service Mark
• Service mark is a name, word, or symbol that
a company uses to distinguish its services
from others
• Excludes others from using the same or
similar mark
• It does not prevent others from providing the
same or similar services
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Copyright
• Protection provided by the laws of the U.S. to
the authors of “original works of authorship”
• Covers literary, dramatic, musical, artistic, and
other types of intellectual works
• Covers both published and unpublished work
• Protects form of expression, not the content or
the subject matter
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Copyright (continued)
• After 1/1/1978, copyright laws protect the
work for
 The author’s life plus 70 years
 the last surviving author’s life plus 70
years in the case of multiple authors
• Currently, no international copyright laws for
worldwide protection
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Engineering Standards and Codes
Developed over the years by various
organizations to ensure product safety and
reliability in services, and uniformity in parts
and components
Why do we need standards and codes?
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Engineering Standards and Codes
(continued)
• Standards allow for easy way to communicate the size of a
product
• For example, if we had global standards for shirts and shoes,
then the above cross referenced tables would not be necessary
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Engineering Standards and Codes
(continued)
Example of an engineered product that adhere to many standards
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Engineering Standards and Codes
(continued)
Example of products conforming to the ISO
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Other Codes & Standards
• ANSI – American National Standard Institute
• ASTM – American Society for Testing and
Materials
• NFPA – National Fire Protection Association
• UL – Underwriters Laboratories
• EPA – Environmental Protection Agency
• ASHRAE – American Society of Heating,
Refrigerating and Air-Conditioning Engineers
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Other Codes and Standards (continued)
• CЄ - Conformité Europeenné
• ISO – International Organization for
Standardization
• BSI – British Standard Institute
• CSBTS – China State Bureau of Quality &
Technical Supervision
• DIN – Germany-Deutsches Institute für
Normung
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Examples of Codes and Standards
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Examples of Codes and Standards
(continued)
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Examples of Codes and Standards
(continued)
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Examples of Codes and Standards
Specific to Civil Engineering Field
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Examples of Codes and Standards
Specific to Civil Engineering Field (continued)
ASCE 7-05: Minimum
Design Loads for
Buildings and other
Structures
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Examples of Codes and Standards
Specific to Civil Engineering Field (continued)
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Examples of Codes and Standards
Specific to Civil Engineering Field (continued)
© 2011 Cengage Learning Engineering. All Rights Reserved.
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U.S. Drinking Water Standards
• EPA sets the standards for the maximum
contaminants that can be in our drinking water
and still be considered safe to drink
• Maximum contaminant level goal (MCLG)
Maximum level of a given contaminant in the
water that causes no known harmful health
effects
• Maximum contaminant level (MCL)
 Slightly higher levels of contaminants than
MCLG
 Levels of contaminants that are legally
enforceable
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Examples of Drinking Water Standards
© 2011 Cengage Learning Engineering. All Rights Reserved.
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U.S. Outdoor Air Quality Standards
• Outdoor air pollution may be classified into:
 Stationary sources: power plants,
factories, and dry cleaners
 Mobile sources: cars, buses, trucks,
planes, and trains
 Natural sources: windblown dust, volcanic
eruptions, and forest fires
© 2011 Cengage Learning Engineering. All Rights Reserved.
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U.S. Outdoor Air Quality Standards
(continued)
• Clean Air Act of 1970
 EPA sets standards for 6 major pollutants:
•
•
•
•
•
•
Carbon monoxide (CO)
Lead (Pb)
Nitrogen dioxide (NO2)
Ozone (O3)
Sulfur dioxide (SO2)
Particulate matter (PM)
© 2011 Cengage Learning Engineering. All Rights Reserved.
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U.S. Outdoor Air Quality Standards
(continued)
• Clean Air Act of 1990
 Required EPA to address the effect of many toxic
air pollutants by setting new standards
• Since 1977, EPA has issued 27 air standards that are
to be fully implemented in the coming years
• EPA works with individual states to reduce amount of
sulfur in fuels and setting more stringent emission
standards for cars, buses, trucks, and power plants
• Need to understand that air pollution is a global
concern that can affect not only our health, but also
our climate
© 2011 Cengage Learning Engineering. All Rights Reserved.
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U.S. Indoor Air Quality Standards
(continued)
• Indoor levels of pollutants may be two to five
times higher than outdoor levels
• Indoor air quality is important in homes,
schools, and workplaces where we spent
approximately 90% of our time
• Indoor air quality is important to our short-term
and long-term health, It affects productivity in
workplace and the learning environment in our
schools
© 2011 Cengage Learning Engineering. All Rights Reserved.
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U.S. Indoor Air Quality Standards
(continued)
• According to EPA, some common health
symptoms include:
 Headache, fatigue, and shortness of
breath
 Sinus congestion, coughing, and sneezing
 Eye, nose, throat, and skin irritation
 Dizziness and nausea
© 2011 Cengage Learning Engineering. All Rights Reserved.
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U.S. Indoor Air Quality Standards
(continued)
• Factors influencing air quality
 Heating, ventilation, and air-conditioning
(HVAC) system
 Sources of indoor air pollutants
 Occupants
© 2011 Cengage Learning Engineering. All Rights Reserved.
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U.S. Indoor Air Quality Standards
(continued)
• Reasons for more exposure to indoor air
pollutants
 Tighter built newer houses that have lower
air infiltration or exfiltration than older
structures
 Using more synthetic building materials in
newly built homes that could give off
harmful vapors
 Using more chemical pollutants such as
pesticides and household cleaners
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Typical Sources of Indoor Air Pollutants
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Methods to Manage Contaminants
• Source elimination or removal examples
 Prevent people from smoking inside
buildings
 Prevent car engines from running idle near
buildings’ outdoor air intakes
• Source substitution example
 Use a gentle cleaning product rather than
a product that gives off harmful vapors
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Methods to Manage Contaminants
(continued)
• Proper ventilation
 Remove sources of pollutants before they can
be spread through the air distribution system
 Use exhaust fans to force out harmful
contaminants
• Exposure control
 ASHRAE establishes codes and standards
for how much fresh outside air must be
introduced for various applications
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Methods to Manage Contaminants
(continued)
• Air cleaning
 Removes harmful particulate and gases
from the air as it passes through some
cleaning systems. It includes systems that
make use of
• Absorption
• Catalysis
• Air filters
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Sustainability in Design
Sustainability and sustainable engineering can
be defined as
“design and development that meets the needs
of the present without compromising the ability
of future generations to meet their own needs.”
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Sustainability in Design (continued)
• Engineers contribute to both private and public
sectors of our society
• In private sector, they design and produce the goods
and services that we use in our daily lives to allow us
to enjoy a high standard of living
• In public sector, they support local, state, and federal
mission such as meeting our infrastructure needs,
energy and food security, and national defense
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Sustainability in Design (continued)
• Increasingly, because of worldwide socioeconomic
trends, environmental concerns, and earth’s finite
resources, more is expected of engineers
• Future engineers are expected to design and provide
goods and services that increase the standard of
living and advance health care, while addressing
serious environmental and sustainability concerns
• In designing products and services, engineers must
consider the link among earth’s finite resources,
environmental, social, ethical, technical, and
economical factors
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Sustainability in Design (continued)
• Potential shortage of engineers with training in
sustainability
• ASCE, ASEE, ASME, and IEEE have come out in
support of sustainability education in engineering
curricula
• Civil engineers play an increasing important role in
addressing the climate change and sustainability
issues that are being discussed nationally and
internationally among policy makers and politicians
© 2011 Cengage Learning Engineering. All Rights Reserved.
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ASCE Sustainability Statement
“The public’s growing awareness that it is
possible to achieve a sustainable built
environment, while addressing such challenges
as natural and man-made disaster, adaptation to
climate change, and global water supply, is
reinforcing the civil engineer’s changing role from
designer/constructor to policy leader and lifecycle planner, designer, constructor, operator,
and maintainer (sustainer). Civil engineers are
not perceived to be significant contributors to
sustainable world.”
© 2011 Cengage Learning Engineering. All Rights Reserved.
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ASCE Actions on Sustainability
• On 11/4/2008, ASCE Board of Direction
adopted sustainability as the 4th ASCE priorities
followed
 renewing the nation’s infrastructure
 Raising the bar on civil engineering
education
 Addressing the role of the civil engineers in
today’s changing professional environment
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Five Issues Must be Understood by
Engineers on Sustainability
• Appeared on 1/8/2009 ASCE News
• Written by William Wallace, founder and
president of Wallace Futures Group,
Steamboat Springs, CO
 Author of Becoming Part of the Solution:
The Engineer’s Guide to Sustainable
Development
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Five Issues Must be Understood by
Engineers on Sustainability (continued)
1. The world’s current economic development is not
sustainable – the world population already uses
approximately 20% more of the world’s
resources than the planet can sustain.
2. The effects of outpacing the earth’s carrying
capacity have now reached crisis proportions –
spiking energy costs, extreme weather events
causing huge losses, and prospect of rising sea
levels threatening coastal cities. Global
population increase outstrips the capacity of
institutions to address it.
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Five Issues Must be Understood by
Engineers on Sustainability (continued)
3. An enormous amount of work will be required if the
world is to shift to sustainable development – a
complete overhaul of the world’s processes,
systems, and infrastructure will be needed.
4. The engineering community should be leading the
way toward sustainable development but has not
yet assumed that responsibility. Civil engineers
have few incentives to change. Most civil engineers
deliver conventional engineering designs that meet
building codes and protect the status quo.
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Five Issues Must be Understood by
Engineers on Sustainability (continued)
5. People outside the engineering community are
capitalizing on new opportunity – for example,
accounting firms and architects. The architects
bring their practices into conformity with the U.S.
Green Building Council’s leadership in Energy and
Environmental Design (LEED) Green Building
Rating System
© 2011 Cengage Learning Engineering. All Rights Reserved.
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IEEE Actions on Sustainability
• In January 2009, the Sustainability Ad Hoc
Committee was formed to map and coordinate
sustainability-related issues across IEEE
• Created the Global Earth Observation System
of Systems (GEOSS) involving in collecting
data from thousands of sensors, gages, buoys,
and weather stations across the globe.
• Goal of GEOSS is to help foster sustainable
development
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Sustainability Concepts, Methods, and
Tools
• Key sustainability concepts – understanding Earth’s
finite resources and environmental issues;
socioeconomic issues related to sustainability; ethical
aspects of sustainability; sustainable development.
• Key sustainability methods – life-cycle based
analysis; resource and waste management (material,
energy); environmental impact analysis
• Key sustainability tools – life-cycle assessment;
environmental assessment; use of sustainabledevelopment indicators; USGBC LEED rating system
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Sustainability Concepts, Methods, and
Tools (continued)
• USGBC stands for U.S. Green Building Council
• LEED stands for Leadership in Energy and
Environmental Design
© 2011 Cengage Learning Engineering. All Rights Reserved.
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USGBC LEED Rating System
“LEED is an internationally recognized green building
certification system, providing third-party verification that
a building or community was designed and built using
strategies aimed at improving perfromance across all the
metrics that matter most: energy savings, water
efficiency, CO2 emissions reduction, improved indoor
environmental quality, and stewardship of resources and
sensitivity to their impacts. Developed by the USGBC,
LEED provides building owners and operators a concise
framework for identifying and implementing practical and
measurable green building design, construction,
operations and maintenance solutions.”
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Summary
• You should know the basic design steps that
all engineers follow, regardless of their
background, to design products and services
• You should realize that economics plays an
important role in engineering decision making
• You should realize that the selection of
material is an important design decision
• You should be familiar with the common traits
of good teams
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Summary (continued)
• You should understand the importance of
project management
• You should be familiar with the concepts of
patent, trademark, and copyright
• You should know why we need to have
standards and codes in engineering
• You should be familiar with the role and
mission of some of the larger standardization
organizations in the world
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Summary (continued)
• You should be familiar with the role of the
EPA and the standards it sets for drinking
water, outdoor air quality, and indoor air
quality
• You should be able to name some of the
sources of indoor and outdoor air pollutants
• You should be able to name some of the
sources of water pollutants
• You should understand the importance of
sustainability in engineering design
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic
• A health service expansion consisted of a physician
office building (POB) and a clinic
• The POB was to attach to the existing hospital with
the clinic connecting to the POB
• The clinic and POB were treated as separate project
with two different design teams worked on them
• Focus of this case study is the Clinic
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 1: Recognizing the Need for a building
• Board of Directors of a clinic recognized the need for
expansion to meet the increasing demand of health
service in their city and its surrounding communities.
• To better serve the people in the communities, the
Board of Directors decided to build a new clinic.
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 2: Define the usage of the building
• The Board defined in detail the types of building
usage
• Parameters considered included: number of
examination rooms, reception areas, laboratory
facilities such as X-ray, MRI rooms, staff rooms,
meeting rooms, and managerial and maintenance
facilities, anticipated number of patients, visitors, and
staff
• Other considerations included future expansions and
future expansion potentials
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 3: Project planning
• Owner identified possible building sites
• The proximity of the hospital and the future POB were
the major factors that led to the building site
• This is a privately funded project, the owner could
have selected an architect or contractor to initiate the
design phase or requested bids from architects or
contractors to lead the project
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 4: Schematic design phase
• Architect designer met with the staff of the clinic to learn
more about how the new clinic was to be used
• Architect designer and contractor learned about the
estimated budget
• Coordinated with architect of the POB because both
buildings shared some common columns and
foundations
• Clinic was designed as a steel frame structure
• Architect designer prepared multiple schematic designs
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 5: Design development (DD) phase
• Architect designer laid out the locations, sizes, and
orientations of the reception areas, examination
rooms, laboratories, business administration offices,
maintenance facilities, entrances to the POB and the
street
• Gridlines were defined according to column locations
• Structural engineers provided the size of major
support components of the building such as beams,
columns, and foundations
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 5: Design development (DD) phase
(continued)
• Mechanical and electrical engineers provided
preliminary mechanical and electrical designs
• A set of architectural drawings with superimposed
structural, mechanical, and electrical information was
provided to the client and the contractor for cost
estimates and review
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 6: Construction documentation (CD) phase
• All the detailed comprehensive designs: architectural,
structural, civil, interior, mechanical, electrical,
plumbing, etc. were performed
• Project manager who represented the architect during
all construction meetings was responsible for
overseeing the completion of the design and document
produced
• Project manager compiled a set of specifications for
the project and checked that the design conformed to
the current building codes
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 6: Construction documentation (CD) phase
(continued)
• Civil engineer was responsible for the grading of the
surface outside the building such as parking lot,
sidewalk, handicap parking signs, and other signs,
drainage of the paved surfaces to the storm water line,
connections from the clinic to the city water line and
sewer line
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 6: Construction documentation (CD) phase
(continued)
• Structural engineer was responsible for the design of
all the load bearing and non-load bearing components
and connections.
 Designs included sizing of steel beams, steel
columns, isolated reinforced concrete footings,
bracing necessary to support wind load, steel joists
to support the roof and snow loads
 Provided design details to support roof top unit and
x-ray equipment
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 6: Construction documentation (CD) phase
(continued)
• Structural design documentation included a set of very
detailed drawings of
 the layout of the beams, columns, and their sizes,
steel joist sizes and spacing;
 connections between beams and columns, joists
and beams, columns and footings;
 steel reinforcing details of the footings;
 masonry wall sizes and steel reinforcements,
metal studs spacing;
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 6: Construction documentation (CD) phase
(continued)

special details to support door and window openings
and other architectural components such as canopy at
entrance
• Since the clinic and POB share some common columns and
foundations, the structural engineer of the clinic provided
design information at the common gridline to the engineer
for the POB
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 6: Construction documentation (CD) phase
(continued)
Typical connection detail between steel beam and column
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 7: Construction administration (CA) phase
• There were weekly meetings between the site superintendent
(from the contractor), the project manager (from the
architects), representatives from different subcontractors
such as electricians, plumbers, steel erectors
• Minutes from each construction meetings were recorded by
the project manager and distributed to all parties
• Periodically, the project manager and site superintendent met
with the owner, to report the progress of the construction and
to address the owner’s concern
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 7: Construction administration (CA) phase
(continued)
• Structural engineer, though not required but strongly
recommended, visited the site to observe the construction
process especially during foundation construction and
framing of the building and to attend the construction meeting
periodically during that time
• Structural engineer reviewed all the shop drawings of
structural components such as beam sizes and length,
connection details
• After the framing was done, other contractors went on site to
do the wiring, plumbing, roofing, installing equipment
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 7: Construction administration (CA) phase
(continued)
Structural engineer’s site observation during construction
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 7: Construction administration (CA) phase
(continued)
• Interior designers began their part of the projects after the
interior part of the buildings was ready such as walls, floors,
and ceilings
• After the building inspector issued the permit of occupancy,
the clinic staff started using the new clinic
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Civil Engineering Design Process – A
Case Study: Health Clinic (continued)
Step 7: Construction administration (CA) phase
(continued)
• Punch list
 Project manager, site superintendent, and the owner
performed a walk-through checking everything to make
sure they were acceptable
 Contractor and project manager took notes of all the
fixes needed and items remained to be finished such as
touch up paint, cleaning, missing cover plate on light
switches
 Owner would hold back the last 5 to 10% of the payment
until he/she is completely satisfied with the construction
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process –
A Case Study: Minnkota Electric Outboard Drive
• Minnkota Electric Outboard
Drive is designed and
manufactured by Johnson
Outdoors in Mankato, MN with
headquarter in Racine, WI
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 1: Recognizing the need for a product or a
service
• Marketing department at Johnson Outdoors recognized
the growing interest in environmentally friendly power
sources for their boating industry
• Marketing department contacted the engineering
department to discuss the feasibility of developing new
generation of motors that are environmentally friendly
• Increasingly, more states were enacting regulations
banning the use of gasoline boat motors in public water
ways including lakes and rivers
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 2: Problem definition and understanding
• The details of the project requirements were defined
• Design specifications included
 Motor had to move a 17 feet long Pontoon at a
speed of 5 mph minimum
 Boat operator had to have the capability to trim and
tilt from a remote console
 Motor had to be compatible with industry standard
steering wheel mechanism
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 3: Research and preparation
• Engineers checked existing design inventory to
determine if a motor already exists that would meet
some or all requirements
• A mechanical engineering student was commissioned to
look at state regulations concerning the use of gasoline
vs. electric boat motors
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 4: Conceptualization
• The engineering designers (12 of them) met on weekly
basis to brain storm and bounce ideas off each other.
• They reviewed the information that was gathered in
Step 3.
• They developed few concepts to pursue further
• An additional idea that surfaced was the use of an
electric linear actuator in place of a hydraulic actuator.
The idea was pursued further.
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 5: Synthesis
• The design engineers began to consider details
• They consulted pertinent codes and standards to make
sure that their design was in compliance
• Most of the design was done in ProE® and prototypes
were built in machine and electrical labs
• The unique design of the propeller required the use of a
manufacturing process known as investment casting
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 5: Synthesis
Exploded diagram of motor
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 6: Evaluation
• Numerical experiments were conducted using
ProMechanica®
• Finite element techniques were used to look at stresses
in critical components of the motor itself and the
mounting bracket and the lifting mechanism
• Numerical experiments were performed to study the
hydrodynamics of propeller designs including thrust,
cavitation, speed, and drag
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 6: Evaluation (continued)
Stress results from finite element analysis
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 6: Evaluation (continued)
• Using GPS, the speed of the boat was measured over a
period of several hours to quantify the motors’ speed a s
a function of time
• The collected data were used to compare to
competitors’ motors
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 6: Evaluation (continued)
Engineers used ProMechanica® to conduct
numerical experiments on the motor
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 7: Optimization
• Based on results obtained from Step 6, modifications
were made to the design and additional analyses
performed
• Results of numerical experiments were used to
optimized the design of propeller and mounting bracket
• Conducted many hours of actual field testing in water
and simulated life testing in labs to help with
optimization of final design
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 7: Optimization (continued)
Actual testing of the system in a lake
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 7: Optimization (continued)
Testing of the system in a laboratory setting
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 8: Presentation
• The product development process took approximately
two years
• During this period design engineers gave
 weekly progress reports to the rest of design group;
 quarterly status oral and written reports to the
marketing department and group vice president
 final presentation to the Board of Directors
• Presentation duration ranged from 15 minutes to an
entire afternoon
© 2011 Cengage Learning Engineering. All Rights Reserved.
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Mechanical/Electrical Engineering Design Process – A
Case Study: Minnkota Electric Outboard Drive (continued)
Step 8: Presentation (continued)
• Presentation addressed several issues including
 Development cost
 Unit cost
 Market outlook
 Performance characteristics
 Testing results
 Environmental impact
© 2011 Cengage Learning Engineering. All Rights Reserved.
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