# Presentation - Career and Technical Education

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26 Νοε 2013 (πριν από 4 χρόνια και 7 μήνες)

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CHAPTER5:

FINAL DESIGN CHALLENGE

Engineering Mathematics

Introduction/Description

2

Individually and/or in teams, you will

complete hand
-
drawings to scale,

build a scale model, and

present a 30
-
minute multimedia exhibition of your
work.

Chapter 5: Outline

3

1.
Beams

2.
Supports

3.
Stress and Buckling

4.
Truss Analysis

Objectives and Results

4

Students will identify the different types of bridges
and the strengths and weaknesses of each design.

Students will use critical thinking, problem solving, and
team work to design, engineer, and troubleshoot a
functional bridge truss design.

Students will develop public speaking and
presentation planning skills.

Schedule of Assignments

5

Class
Period(s)

Topic(s)

Assignment

1
-
2

The Engineering Design
Process
-

quick
r
eview

Student
background of

the Capstone Project

Vocabulary

Chapter 5.1

#
1
-
Individual:

EDP review, vocabulary,

capstone Project Handout

3
-
5

Introduction to truss
analysis

Chapter 5.2

#2
-
Individual:
Truss Analysis Handout/Worksheet

6
-
30

Scale diagrams and
drawings

West Point Bridge Design
(WPBD)

Chapter 5.2

#3
-
In teams of 2
-
3; Do drawings either

and build your scale model of a truss bridge.

Use WPBD to test and

hold the most weight possible

(Major)

Schedule of Assignments, cont.

6

Class
Period(s)

Topic(s
)

Assignment

31
-
60

Model: design and
build

Chapter 5.3

#4
-
In teams of 2
-
3; Apply the engineering

design process to the scenario given;

complete
the
model for

the
rubric
given

(Major)

61
-
80

Presentation
preparation on truss
designs

and analyses

Chapter 5.3

#5
-
In teams of 2
-
3;
Complete
the engineering

design process
for the
scenario given;

complete
a
presentation

following
the

rubric given

(Major)

81
-
90

Presentations

Destructive testing of

bridge truss designs

Chapter 5.4

#
6
-
In teams of 2
-
3; complete the engineering

design process for the scenario given;

deliver the multimedia presentation

of your design following the rubric given.

Test bridge designs using destructive

testing

equipment as instructed.

(Major)

Results

7

Students will present a design, drawings, model, and
other information about bridge truss design, using
appropriate mathematical formulas, mathematical
design analysis, and associated programs.

Vocabulary

8

Arch bridges

Beam

Bridge

Bracing

Catenary

Deck

Deck Truss

Forms, or Types of Bridges

Vocabulary, cont.

9

Materials

Model

Parabola

Pony truss

Vocabulary, cont.

10

Span

Stringer

Strut

Suspension Bridges

Symmetry

Vocabulary, cont.

11

Technical drawing

Tie

Truss

Truss bridges

Engineering Problems and Solutions

12

Often, engineers encounter problems and must solve
these problems using mathematical formulas and test
data analysis.

You and your teammates will be solving similar issues
by addressing the crucial elements of the engineering
design process and using
mathematical
analysis
and
mathematical
formulas for bridge truss
design.

Mathematics in Construction

13

Obviously, architecture is geometric

mathematics.

Consider
blue
prints,
for example. A blue print is the
paper layout, drafted by an architect, which
illustrates the design of a building.

Mathematics in Construction, cont.

14

Math also provides architects with a solution to the
question of possibility.

Think
of yourself as an architect.

In
dream
up a beautiful
building

that you
can actually picture
in

How
does that dream building become a blue
print?
Or become
an actual structure
?

Math in Everyday Construction

15

It is not only architects who design and build practical
structures.

Every day
people commonly do construction work to
their houses and yards.

It
would be very expensive to hire an architect if you
just wanted to build a fence or a new deck.

Sample Problem

16

For example, imagine you are redecorating your
living room.
You
want to hang three pictures on the
wall in a triangular shape
.

You
realize that you must put the nails in the vertices
of an equiangular triangle in order to create the
shape you want.
However
, the studs in the wall are
spaced
40 cm
apart.

How do you figure out where to put the nails?

Solution to Sample Problem

17

60
°

60
°

60
°

40cm

40cm

x

Solve for x: tan60 =
x

40

Bridges Overview

18

A
bridge is a structure built to span physical obstacles
such as a body of water, valley, or road, for the
purpose of providing passage over the obstacle.

Bridge Factors

19

There are
four main factors
that are
used in describing
a bridge
.

Span
(simple, continuous, cantilever
)

Material
(stone, concrete, metal, etc
.)

Placement
of the travel surface in relation to the
structure (deck, pony, through
)

Form/type
(beam, arch, truss, etc
.)

Bridge Identification Factors

Curves in Bridge Design

20

There are two curves with very similar shapes that are
important in bridge
construction:

Catenary

Parabola

Symmetry

21

Symmetry is
a way to describe shapes and design
and to organize geometry.

Architecture
encompasses
basic line symmetry and
other types, such as

rotational

spiral,

c
ylindrical,

chiral,

s
imilarity, and

translational.

Forms (Types) of Bridges

22

While there
are many different types of
bridges, we
will focus on truss bridge designs.

With over 30 different types of truss designs, we will
cover 10 of them.

Types of Bridges

23

Three main types
of
bridges
are

1.
arch,

2.
truss, and

3.
suspension.

1

2

3

Truss Design #1: Pratt Truss

24

Truss Design #2: Warren Truss

25

Truss Design #3: Whipple Truss

26

Truss Design #4: Parker Truss

27

Truss Design #5: Baltimore Truss

28

Truss Design
#6: Pauli or Lenticular

29

Truss Design
#7: Bailey Truss

30

Truss Design
#8:
L
attice Truss

31

Truss Design
#9: Parker Camelback

32

Truss Design
#10: Howe
Truss

33

Bridge Analysis Factors

34

Span

Environmental influences

Budget

Soil characteristics

Building time frame

Analyzing Bridge Designs

35

Analyze the bridge designs based on the following
elements:

Length of span

Height

Materials to be used

Tools available

Weight to be held

Racking

Creating a Scale Drawing

36

A scale drawing is a
drawing that shows a real object
with accurate
sizes.

Sizes are reduced
or enlarged by a certain amount
(
the
scale
).

The example drawing below has
a scale of "
1:10."

Scale Drawing and Ratios

37

Scale of a drawing = drawing length : actual length

For example, a map cannot be of the same size as
the area it represents. A ratio is used.

A
scale is usually expressed in one of two
ways:

using units or

1
cm to 1 km

1” = 1’

w
ithout
explicitly mentioning
the measurement units.

1:100,000

1:10

Scale Drawing in Architecture

38

Engineering Drawing Example

39

Scale Drawing Practice

40

Complete scale drawings for your project.

hand
-
according to the scenario and team project outline
and rubric.

Scale Models

41

A scale
model is a physical
model. It is a
representation or copy of an object that is larger or
smaller than the actual size of the
object.

A scale model maintains
the
related
proportions
(or
the scale) of
the physical size of the original object.

Usually, the
scale model is used as a guide to making
the full
-
sized object.

You will be creating scale truss bridge models.

Scale Model Examples

42

A model is a three
-
dimensional (3
-
D) alternative for a
2
-
D
representation. An
example
of a scale 3
-
D model
versus a scale drawing would
be a
globe,
which is
the
3
-
D
alternative to a
flat 2
-
D
world map.

Scale Model Examples

43

From Scale Model

To Construction

To Completed Building

Creating a Scale Model

44

Much like creating a scale drawing, when creating a
scale model, you have to decide on certain crucial
design components, such as

measurement (length, height, width, depth, etc.),

real life applications,

design constraints,

design requirements,

materials, and

scale.

Building a Scale Model

Four Forces and Bridge Design

45

Several forces and formulas should be considered when
designing:

Compression

Tension

Torsion

Shear

Formulas and Bridge Design

46

Compression and tension caused by a bridge’s load
can cause racking.

Analyze and counteract racking in your design.

West Point Bridge Design (WPBD)

47

West Point Bridge Design Contest

http://
.

Visit the WPBD
tutorials

to learn how to use the
software.

Visit the WPBD FAQs at
http://bridgecontest.usma.edu/qcontest.htm
.

video
.

Bridge Truss Models

48

In teams, after analyzing the various designs and
their strengths and weaknesses, design the strongest
and lightest weight bridge to the specifications
indicated in the student design brief.

In teams, create your bridge truss using 100 Popsicle
sticks and glue only.

Get approval for using your design with your
instructor.

Scale Drawings

49

Complete
hand
-
drawn or
scale diagrams and
drawings.

Your group should be prepared to present the

Problem statement and how you solved your problem using
the engineering design process

Scenario

Racking and Geometric Figures

50

Explain how your design counteracts racking based
on geometric and algebraic principles.

Which type of geometric figure is the best to
counteract tension and compression?

Analyze which type of figure is the most efficient.

Build
a
Scale Model

51

criteria
.

You should complete a CAD or hand
-
drawn design on
paper and have a design approved by your
instructor before receiving your materials to build.

Weights and Measures

52

Weigh 20 popsicle sticks using a scale.

Convert the sticks’ weight into pounds.

Estimate the final weight of your bridge based on the
following different configurations.

45 sticks

60 sticks

100 sticks

Weights and Measures, cont.

53

Measure your bridge truss design using a ruler or
yardstick.

Record the metric and English standard measurements

o
verall length,

t
otal height, and

t
otal width.

Orthographic Drawing Example

54

Bridge Design Presentation

55

P
resent a
30
-
minute
multimedia exhibition of
your
team’s bridge design work.

See
criteria
.

View the websites below, before giving presentation.

How to Increase Self
-
Confidence in Public Speaking

Public Speaking Tutorial

Credits

56

ClipArt;

http://www.clipart.com/en/

Images;

http://commons.wikimedia.org/wiki/Main_Page

Slide 44

Building a Scale Model video; from YouTube user;
Steve Maxwell;

Credits, cont.

57

Slide 47

How to Set Up a Bridge Design Using WPBD video;
Learninreturn
;

Slide 55

How to increase self
-
confidence in public speaking
VideoJug
;

Credits, cont.

58

Slide 55, cont.

Public speaking tutorial video; from YouTube user;
Camille
Valvo
;