Building Structure Project 1

ARC 2523 Project 1 Fettuccine Truss Bridge

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ARC 2523 BUILDING STRUCTURE

PROJECT FETTUCCINE BRIDGE REPORT

Chan Pin Qi 0314676

Lim Yee Qun 0319121

Te Li Theng 0314198

Liew Qiao Li 0315671

Woo Wen Jian 0315123

9th October 2015


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TABLE OF CONTENTS

CHAPTER 1: INTRODUCTION 1.1 Introduction to the Project 1.2 Aim and Objective 1.3 Scope 1.4 Limitations 1.5 Equipment and Materials Used 1.6 Testing of Materials 1.7 Methodology 1.8 Schedule of Work

3 4 5 5 6-9 10 11-12 13

CHAPTER 2: PRECEDENT STUDY

2.1 Wadell “A” Truss Bridge, Parkville, Missouri 2.2 Design Strategies and Load Distribution 2.3 Trusses and Connection

14 15 16-17

CHAPTER 3: EXPERIMENTATION AND PROGRESS 3.1 Bridge Truss Design 1 vs Bridge Truss Design 2 3.2 Bridge Truss Design 3 3.3 Bridge Truss Design 4 3.4 Bridge Truss Design 5

18-21 22-23 24-25 26-27

CHAPTER 4: FINAL BRIDGE 4.1 Amendments 4.2 Top & Bottom Chord 4.3 Core Horizontal Element 4.4 Vertical & Diagonal Truss 4.5 Joints 4.6 Members & Connection of Fettuccini Bridge 4.7 Joint Analysis 4.8 Final Model Making 4.9 Final Bridge Test and Load Distribution 4.10 Calculation of Distribution of Forces for Final Bridge

28 29 30 31 32 33 34-39 40-44 45 46-50

CHAPTER 5: REFERENCES 51

CHAPTER 6: INDIVIDUAL CASE STUDIES 6.1 Case Study 1: Chan Pin Qi 6.2 Case Study 2: Lim Yee Qun 6.3 Case Study 3: Te Li Teng 6.4 Case Study 4: Liew Qiao Li 6.5 Case Study 5: Woo Wen Jian

52-55 56-59 60-63 64-67 68-71


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Chapter 1: Introduction

1.1 Introduction to the Project

This project is commissioned by AR2523: Building structures. In a group of five, students are

assigned to build a bridge using fettuccine as the materials for the bridge truss members.

The weight of the bridge must not be more than 80g, but is required to carry a much larger

weight for an extended period of time. The clear span of the bridge must be at least

350mm.

With many unknown variables, including its compression and tension capabilities, students

are asked to experiment with different kind of methods of joint and designs to determine

the best design for a bridge. Students will learn to explore truss members using different

arrangements to achieve the best performance and how to build the prefect truss. Students

are to find out the strength of each design by testing out and find out its tension and

compression forces.

Students will then apply the knowledge of calculating the moment force, reaction force,

internal force and force distribution of a truss. By identifying all these forces, students will

be able to enhance their design by determining which members need amendment in order

to make it stronger.

This report contains information regarding the students' analysis and documentation of the

experimentation with several fettuccine truss bridge designs. Individual case studies are also

in these reports, along with insight and suggestions for improvement.


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1.2 Aim and Objective

The aim of this project is to develop students' understanding of force distribution in a truss.

It also aims to teach that different design and construction methods can alter the efficiency

in withstanding loads.

The objective of this project is to discover the most efficient bridge design with fettuccine as

material in regards to its tension and compression capabilities. Students are also to learn

how different forces (tension and compression) to affect a bridge efficiency, especially

considering fettuccine as a relatively weak materials.

Also, the project aims to teach students to build a perfect truss, a truss design with high

aesthetic value, and at the same time with a minimal construction material that could

withstand a high amount of loads.


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1.3 Scope

The scope of this project was to use only fettuccine as the construction material. The bridge

constructed is required to have a clear span of 350mm and a weight lesser than 80g. Prior to

deciding the final truss bridge design, process such as preparing precedent studies, material

durability test, model making and load testing process were conducted. This is to explore

which ways that could enhance the bridge design to hold more loads.

1.4 Limitations

Our main limitation was that the weight of the bridge must not exceed the range of

80grams. This caused us to carefully study how do the forces distribute in the bridges that

we designed and how could we enhanced the strength of the bridge design and at the same

time, to minimize the construction materials. Consequently, a lot of designs were produced

in order to get the perfect design.


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1.5 Equipment and Materials Used

San Remo Fettuccine: San Remo brand’s fettuccine is the best in term of cost to

compression strength compared to the other brands during the

material durability test.

Cutting knife: Cutting knife was used to cut the fettuccine to pieces during the

making of the bridge truss to achieve the precision that is close to

what we wanted to design.

3-second glue: Used when gluing the bridge joint together. It has great adhesion

strength that allows fettuccine to join together in about 3-5 seconds.


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Cutting mat: Used to protect the table surface when cutting the fettuccine as well

as the edges of the fettuccine.

Steel Ruler: Used to measure the length and marking on each fettuccine before

cutting it.

Sandpaper: Used to smoothen the edges of the fettuccine after cutting and

before gluing.


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500 ml water bottle: Used as load during the load testing of the bridge. It is much more

faster to test out the designs this way.

Thin ropes: Used to hang both centre components and S hook together. The

force distributed is much more even compared to using the s hook to

the centre component

Phones: Used to record and document the results of each of the designs

during the test.


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S-hook: Used to connect the rope and the bucket.

Electronic balance: To measure the weight of the bridge truss and the weight of the load

applied on the bridge.

Bucket: Used as a load by filling it up with water during the load testing.


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1.6 Testing of Materials

Testing of durability of construction materials

Brands Analysis (durability test with 10 strands of fettuccines)

Kimball Withstand up to 4 cups of water

Prego Withstand up to 5 cups of water

San Remo

(CHOOSEN as construction

materials)

Withstand up to 6 cups of water

Testing of the adhesive strength

Types of adhesive Analysis

UHU Glue -Slowest solidify time duration (30seconds)

-Average strength efficiency

-Weak bond efficiency

3-Second- Glue

(CHOOSEN as adhesive

materials)

-Fastest solidify time duration (3-5 seconds)

-High strength efficiency

-High bond efficiency

-Causes bridge to be brittle after leaving it for a day


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1.7 Methodology

Step 1: Prior to designing, a precedent study were conducted to understand how a truss

bridge works and how does force distribute in the bridge. Then we tested out different

brands of fettuccine as well as different brand of adhesives, this is to sort out which is the

best and most cost effective among all of the choices in the market.

Step 2: We first understand how forces act on a fettuccine. We tested the tension and

compression strength of the fettuccine, we simply tried to pull the ends (tension) and push

them together (compression). We found that the compressive strength of fettuccine is

weak, while it has great tensile strength.

Step 3: Upon understanding from the precedent study, we sketched a few possible designs

for an efficient perfect truss bridge. We had to be sure to design it for a clear span of

350mm (leaving 50mm on the sides to hoist up on the table).

Step 4: Proceed to build the bridge. The elevations of the bridges were cadded in AutoCAD

and then printed out. This is to ensure precision when we cut and join the fettuccines

together. Then, we did a quality check on the packets of fettuccines and sorted out the

straight ones and the twisted ones.

Step 5: Then, pen knives are then used to slice the fettuccine members to the correct

length. To join them together laterally, the first layer contain two equally sized fettuccines

and connected with a second layered fettuccine that connects both of them, while the sides

of the second layered are filled with fettuccines of desired length. Also we did made sure

the joints did not line up, so as to avoid breakage.

Step 6: Using three-second glue, the members are join together. Alignment is also crucial in

this process, as is craftsmanship. Joints must fit together perfectly, without unnecessary

gaps between them. Amendments can hardly be done as 3-second-glue has a very strong

adhesive strength. Thus, precision is crucial in this step.


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Step 7: After waiting for the three-second-glue dry properly (at least 5 minutes), the bridges

are ready to be test out. To test the bridge, we set two tables (of equal height) exactly

350mm apart, and set the bridge in the middle. In preparation for the bridge testing, we

must first weight the bridge to see how far above or below the 80 g mark we are. After

documenting the weight, the S hook and bucket are weight to calculate the total weight of

the load that will be hung from the bridge.

Step 8: A thin rope is tied on the midpoint or centre point of the bridge to the S hook, the S

hook is then used to connect the thin rope and the bucket handle. The bucket does not

elevate too far above from the ground, this is to avoid the bucket to break upon falling

impact.

Step 9: Using a 500ml water bottle (filled to the very top), water is slowly poured into the

bucket. As load is being added, the bridge is checked for any deformities. As the fettuccine

begins to deform, the points where the bridge are the weakest will then be noted down. We

then continued pouring until the bridge broke. Using the 500 ml bottle as a reference, we

calculated how much water was poured in.

Step 10: Based on the observation, the strength of the bridge is studied and the design is

refined accordingly by enhancing its weak points. We strengthened the parts that deformed

quickly and parts that snapped upon heavy loads are applied to the bridge.

Step 11: Step 4 to step 10 were repeated to upgrade and refine the design of the fettuccine

bridge until the design can hold a desirable loads as well as a mass that is lesser than 80g.


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1.8 Schedule of Work

9th Sept 2015 Experimentation on the most durable brand of fettuccine and the

adhesive with the most strength.

Research and preliminary sketches, discussion of possible design ideas

for Bridge#1

15th Sept 2015 Deciding on the design of the first bridge to be built


for Bridge#2

19th Sept 2015 Building of Bridge#1 and Bridge#2

23th Sept 2015 Discussion of the weakness of Bridge#1 and Bridge#2 on its designs.

Joints have the most weakness.

Discussed possible method to join members together.

Introduced I-beams to designs.

26th Sept 2015 Research and preliminary sketches, discussion of possible design ideas

for Bridge#3.

Building of Bridge#3.

Testing of Bridge#1, Bridge#2 and Bridge#3.


for Bridge#4.

27th – 28th Sept 2015 Building of Bridge#4.

Testing of Bridge#4.


for Bridge#5.

Building of Bridge#5.

Testing of Bridge#5.

Decided on Bridge#5 as the design for assessment.

Building of Bridge#6

Assessment of Bridge#6


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Chapter 2: PRECEDENT STUDIES

2.1 Wadell “A” Truss Bridge, Parkville, Missouri.

Figure 2.1.1 Elevation of Waddell "A" Truss Bridge

Other name:

Linn Branch Creek B ridge

Location:

English Landing Park, Parkville

History:

The Waddell “A” Truss Bridge also known as Linn Branch Creek Bridge is located in Parkville,

Missouri. The bridge was formerly built for the Quincy and Kansas City Railway in 1898. In

1939, it had been abandoned; however it was converted into a highway bridge in 1953. In

order to make room for Smithville Reservoir, it had been disassembled by the U.S. Army

Corps of Engineers in 1980, but the bridge was then re-assembled in English Landing Park,

Parkville in 1987 and open only for pedestrian.


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2.2 DESIGN STRATEGIES AND LOAD DISTRIBUTION

Waddell “A” truss bridge was documented by the Historic American Engineering Record. It

was designed by the well-known American Engineer John Alexander Low Waddell. Waddell

stated that, “the truss was considered as an economical short-span, pin connected structure

and without excessive vibration, the bridge is capable in supporting heavy traffic. “

The members along the top chord which supporting downward forces are in compression

whereas the members along the bottom chord are in tension. While the members joining

the top and bottom chords which are the web members, they may be in tension or

compression due to the different angles used and the different distribution of loads.

Figure 2.2.1 Load distribution diagram


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2.3 Trusses and Connections

Figure 2.3.1 Side views of the bridge showing its abutment and top view of its detail view of its lateral bracing.

Figure 2.3.2 Detail of Truss Connections and Members by John Alexander Waddell


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Chapter 3: EXPERIMENTATION AND PROGRESS

3.1 Bridge Truss Design1 vs Bridge Truss Design2

Diagram 3.1.1 The Drawing of the first bridge.

Figure 3.1.2 Bridge after load test. Figure 3.1.1 Preparing for the first test.

Through our research, we decided to use the style of the Waddell “A” Truss Bridge as our

guideline on our bridge truss design. As to kick start our experiment, we started with

making 2 different designs of Waddell “A” Truss Bridge to identify which design has a

better proficiency.

In order to test the proficiency of the bridge, we made the bottom chord into I-beam

design due to most of the tension of the bridge is rely on bottom chord. Therefore, by

adding I-beam able to enhance the strength and maximum load carry of the bridge.

Besides that, we also apply sandwich joint in order to make a few layers for the truss

bridge.


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Diagram 3.1.2 Breakage point of Bridge1, which all located at the bottom chord.

3.2 Bridge Truss Design2 (Chosen to Further Improvise)

Bridge Weight 81g

Load Carried 1300g

Efficiency 20.86

Figure 3.1.3 The truss of Bridge1 detached

from bottom chord.

Figure 3.1.4 The bottom chord of Bridge1

breaks nearby the joint connection.

During the load testing experiment, although the truss did not break but it was detached from

the bottom chord at certain amount of load. Besides, I-beam was used as our bottom chord to

enhance the efficiency of the bridge but we do not realized that the connection of I-beam also

affect the bridge to break down. This is because the breakage of bridge occurred at the bottom

chord and also it breaks at the part where we join the fettuccines together.

From our observation of this experiment, we believed that the failure of the bridge occurred

mainly due to our poor workmanship.


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Diagram 3.1.3 The drawing of second bridge.

Diagram 3.1.4 Top Elevation of

the joint.

Figure 3.1.5 Applying the joint in

Bridge1.

Figure 3.1.6 Applying the joint in

Bridge2.

This is our second design of Waddell “A” Truss Bridge. In order to test the proficiency of both

the first and second design, we used the same method such as using the same dimension to

make the bridge, to connect the truss and also I-beam acting as our bottom chord.


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3.3 Bridge Truss Design3

Bridge Weight 80g

Load Carried 2500g

Efficiency 78.0

Figure 3.1.7 The bottom chord of Bridge2 break into half.

Figure 3.1.8 Heavy load caused the i-Beam break.

During the load testing experiment, the adhesive of the truss was strong and able to holds the

bridge from detaching the bottom or/and top chord. However, I-beam as bottom chord of the

bridge was broken into half due to the load it carry and also the joint connection of I-beam.

From the experiment, we have concluded that with the strong connection from using the

adhesive, it helps the truss bridge to carry more load and bottom chords also take major part to

withstand the tension of the whole bridge. Hence, the connection of the joint should be

carefully taking in consideration during the making process.

Throughout both load testing experiments, we have decided to use Bridge Truss Design 2 as

because it has better proficiency compare to the first design. Thus, we will be improvising this

design by its adhesive, joint connections and orientation of the trusses.


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Diagram 3.2.1 The drawing of the third bridge.

Diagram 3.2.2 Orientation of the member and

its connection with the C-beam on top chord.

Figure 3.2.1 Bridge after load test.

This is our third design, an improvised version of Bridge2. In this design, we replaced the previous

joint method with double layered fettuccine to strengthen the members’ individual tension

strength. We also change the top chord to C-beam so that it can withstand more forces. The

changes were made as the previous design snapped its top chord completely, thus we assume that

the top chord should contain a stronger member. Also we lowered down the height of the

fettuccine bridge to 60mm as the truss would endure lesser forces exerted on them.


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Diagram 3.2.3 Breakage point of Bridge3.

Bridge Weight 98g

Load Carried 4692g

Efficiency 224.64

Figure 3.2.4 The I-Beam on bottom chord break

into half. Figure 3.2.3 The C-Beam on top chord

break into parts.

Due to the joints between members and top chord is not suitable for C-Beam, it did not sustain long

and then break. While most of the load goes to I-Beam on bottom chord and caused the bottom

cord break into half.

From the experiment, we have concluded that fettuccine is stronger when it is vertically facing

compared to horizontal facing. This principle applied to fettuccine constructed C-beams as well. The

reason this bridge failed is because we place the C-beams at the top chord horizontally, which

increase its compression force and can’t hold more force than we expected it to be. Eventually this

ends up with bottom chord to mainly supporting the whole load, thus it easily breaks before more

loads are applied.


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This is our forth design. By learning what we did wrongly on the third bridge, we changed to

I-beams on top chord so that it will enhance its tension strength. We also shrink the length

of the top chords and truss members to 350mm so that both the sides will have an extra

50mm span. This is because we realize that way will allow more force to be distribute to the

sides of the table, thus the members and chords will have lesser work to do. We also change

the direction of the member that are facing outwards to inwards after knowing they will

work more efficiently when placed, to enhanced the member strength, we also made it into

double layered members.

Diagram 3.3.1 drawing of the third bridge

Figure 3.3.1 I-Beam is

used for both truss and

bottom chord.

Figure 3.3.2 Two i-Beam are used as the core

horizontal member to hang the one-point-load.

Diagram 3.3.2 Orientation of the member and its connection with I-beam top chord

Figure 3.3.2 picture showing the bridge


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Diagram 3.3.3 Breakage point of Bridge4.

Bridge Weight 102g

Load Carried 6300g

Efficiency 389.11

Figure 3.3.3 The members detached from each

other due to the i-Beam break.

Figure 3.3.4 The bottom chord break.

During the experiment, the bridge remains as it is when a load of 4000g were applied on it. But

when it breach the 4000g mark, it started to deform and bending occurred at the bottom chord.

At the end of the experiment, the bottom chord breaks as well as the joint that join truss

members and top chord together. From there, we realized that the workmanship needed to be

really precise so that the members can be correctly received the force distribution so that when

forces will distribute evenly throughout the bottom chord.

And special mention to the shrunken length of the top chord and members. This allow the

bottom chord to be longer than the top, which makes the extra spaces at the two sides. This we

observe that it helps quite a lot in term of helping the bridge to exert forces to the side of the

tables.


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Diagram 3.4.1 The drawing of Bridge5.

Figure 3.4.1 Perspective view of Bridge5. Figure 3.4.2 Layers of Fettuccine stick together to

build all the truss members.

Figure 3.4.3 Fettuccine cut in angle. Figure 3.4.4 Core horizontal members stick

inside the i-Beam (Bottom Chord).

In our fifth design, the difference between this design and the previous one is we replaced the top

chord with the double layered fettuccine, added bracing to the four members closest to the

centre and also added another layer to the bottom chord making it a 3 layered fettuccine I-beam.

We also enhanced our workmanship by making it more precise.


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Bridge Weight 81g

Load Carried 8360g

Efficiency 862.83

Figure 3.4.5 The central element in the middle

break.

Figure 3.4.6 One of the horizontal element break.

During the test, the bridge acted quite different compared to the forth design. Rather than the

bottom chord started to deform. It was the two ends that expanded out started to stretch

themselves at the table. While reaching 6000g mark, the bottom chord, members and top chord

are all still in place and didn’t deform at all. When it reached the maximum load it could take, only

the centre core member snapped and all the other remain in place.

Conclusion, we choose this design as our final design. This is because it could withstand a high load

and also only the centre member break, which means the force distribution in this design is very

even until a point where all our previous problems with breaking of the top chord and bottom

chord are solved.


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4.0 Final Bridge

4.1 Amendments

The final bridge design is same as the 7th fettuccini bridge we made previously as it’s

efficiency is the highest among the bridges we made that withstand 11 Kg. However, the

previous bridge we can make can only withstand 7.3Kg. We are using the same dimension

for the final bridge but different enhancement on particular members, which do not carry

much weight to control the total weight of the bridge to meet the requirement.

Diagram 4.0.1 Final Fettuccini Bridge


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4.2 Top & Bottom Chord

Fettuccini is weak in compression but good in tension. Therefore, several layers are added

to enhance the ability to withstand compression force. After comparing the 6th (I-Beam as

the top main diagonal members and the horizontal member) and 7th (I-Beam as the

horizontal member only), we found out that the main supporting members that withstand

the highest weight among others members is only the longest horizontal span which have

direct contact with the ground surface.

Therefore, amendments are made, where we remove the I-Beam for the top main diagonal

member to reduce the weight of the whole bridge. After several tests on the design of I-

beams, we concluded that those I-Beams that consists of two layers of fettuccini

horizontally and vertically (further explanation in later paragraph) are the strongest among

others.

I-Beam

Without

I-Beam

Figure 4.2.1 I-beam as the top chord

member Figure 4.2.3 Two layers of fettuccini as top

chord member


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4.3 Core Horizontal Element

The Core horizontal element is amended into cross arrangement as it provide more stiffness

for the load to fix in its direction. The upper two pieces of fettuccini is added so that the

core form a triangle to fit the S hook accurately.

Cross I-beams

Diagram 4.3.1 close up look of the core members Figure 4.3.3 Cross arrangement of core member

Figure 4 3.1 I-Beams on both side of the strut Figure 4.3.2 I-beam made up by 4 layers of fettuccini

(middle) between 2 one-layer fettuccini (top and bottom).


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4.4 Vertical & Diagonal Truss

Amendments are made in the trusses as well. Adding more diagonal force in opposing

direction help in increasing tensile strength after the calculation. These members are fewer

layers than the main horizontal spans as they act as aiding members.

Figure 4.4.1 Previous design of the truss Figure 4.4.2 After design of the truss

Diagram 4.4.1 Compression force in the previous truss design

Diagram 4.4.2 Tension force in the after truss design


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4.5 Joints

For the top chord and bottom chord, amendments are made. For top chord, the fettuccini

layers are reduced to one piece as it does not carry much force. For the bottom chord, the

position of putting it between the two I-beams enhance the direct distribution of

compression force. Rather than putting it on top of the two I-beams, they are joined in

between.

For the joint in vertical and diagonal truss, fettuccini is cut into angle that fix securely on each

other. This is to prevent unnecessary force such as shear force from happening and thus

enhance the distribution of force.

Figure 4.5.1 Previous join which do not cut

in angle

Figure 4.5.2 Current joint with accurate angle

Diagram 4.5.1 Roof truss that sit on the top chord Diagram 4.5.2 Base trusses that sit between the bottom

chords


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4.6 Members and Connection of Fettuccini Bridge

6 layers of Fettuccini



Diagram 4.6.2 Upper part and middle part of the bridge

joint

Diagram 4.6.1 Bottom part of the bridge joint


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4.7 Joint Analysis

Bottom Chord

The bottom chord of the bridge used the I-beam design after experienced the failure of

using the C-Beam connection. The I-Beam is formed by two layers of vertical member in

between two layers of horizontal layers of each side. The requirement length of the clear

span is 35cm.

Diagram 4.7.1 Bottom Chord of the bridge

The extension joint

Due to the limited length of available fettuccini,

which is 20-25cm; extension of the fettuccini is

required. However, the extensions need to be

carefully planned to avoid the overlapping of

extension joint.

The beam is arranged in the longer span in the

middle with shorter span both side while

another layer with both side almost equal

lengths. This is to avoid overlapping of extension

joint which will strongly affect the strength of

the span. The horizontal element of the beam

works in the same way. The total length of the

horizontal span is originally 40cm with 2.5 cm

each side that sit on the table. We modify the

total length of the span is 45cm with 7.5 cm on

each side to enhance the tensile strength.

Diagram 4.7.2 Exploded drawings of fettuccini

extension joint


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Top Chord

Diagram 4.7.3 Top Chord of the bridge

The top chord is cut into angle to fit into another top chord to

form a prefect triangle.

Two layers of fettuccini overlaying each other make up this top

chord rather than I-Beam as it increase the weight of the bridge.

It is due to the aid of the vertical acting as tension force to

reduce the burden of top chord which suffering compression

force.

The Strut is stick beneath the

top chord to act as support

rather than locating in the

middle of the top chords. This is

to ensure compression force

(Top chord) is evenly distributed

to the other vertical and

diagonal members.

Figure 4.7.1 Top chord joint supported

by strut

Diagram 4.7.4 Strut as supporting member beneath the top chord


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The vertical and diagonal truss is crucial in distributing the

force asserted by the load. The vertical and diagonal truss

withstands more tensile strength in the middle part where

the load being located. The diagonal truss in the middle part

is in different direction of the other diagonal truss direction.

It was done purposely to provide tension strength at

particular member.

The cross bracing include one long truss (blue) which act

in different direction with another two shorter truss (red)

for the same direction member. This is to ensure securely

strong truss to withstand force, preventing from breaking

so easily.

Diagram 4.7.6 Tension distributions in the

diagonal member (Cross Bra0cing)

Figure 4.7.2 The formation of cross-bracing.

Vertical and Diagonal Truss

Diagram 4.7.5 Vertical and Diagonal Truss


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The vertical and diagonal trusses are located in between the top chord and the bottom chord

rather than surrounding the chord. This is to ensure direct force distribution of force throughout

the other members. Tests are done with vertical and horizontal element being put surrounding the

chord, the weight carried is lower.

Diagram 4.7.7 The joint of vertical and diagonal

member between the top and bottom chord

Diagram 4.7.8 Close up look of the vertical and

diagonal member


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Core Horizontal Member

The Core horizontal member must be as strong as possible because it is the load is directly

asserted on it. The core element must have great tension force to overcome the direct

compression force from the load. Therefore, I-beam design is applied. The overlapping of two I-

beams on each other provide 4 times stronger than without crossing. The core elements sit on

the bottom chord as it direct transfer the load to the nearest and strongest member (Bottom

Chord).

Diagram 4.7.9 The core horizontal member of fettuccini bridge

Figure 4.7.4 Front elevation of crossing of I-

beam like core horizontal member

Figure 4.7.5 Side elevation of crossing of I-beam

like core horizontal member

Diagram 4.7.9 2 extra piece of fettuccini on top of the core


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Figure 4.7.6 The cross bracing in upper truss

Horizontal Truss

The horizontal trusses are inserted to prevent torsion force in the bridge when load is

applied. The force rarely distribute in between these members, therefore, only one layer

of fettuccini is required. However, those who are nearer to the core element where the

load located and at the end of the bridge are 2 layers.

Diagram 4.7.10 Upper and Lower Truss


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4.8 FINAL MODEL MAKING

Firstly, an accurate Autocad drawing of the bridge is printed out as the guide for the bridge

construction. Then, two I-beams are constructed as the base of the bridge

Diagram 4.8.1 The arrangement of fettuccine

in I-beam construction.

Figure 4.8.1 Close up picture showing the

construction of I-beam with Fettucine.

Diagram 4.8.2 The connection of Fettuccine inside I-

Beam.


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Secondly, the outline of triangle is constructed.

Diagram 4.8.3 The second step of erection, the

outline of the triangle.

Diagram 4.8.5 The construction and the connection of the triangle.

Diagram 4.8.4 The connection between the

triangle and I-beam.


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Thirdly, the vertical members are constructed. These member are purposely constructed to support

the whole structure and resist the compression and tension force.

Diagonals are added after that to resist part of the tension and compression forces and avoid shear

forces.

Diagram 4.8.6 Third step of erection, the vertical members.

Diagram 4.8.7 Forth step of erection, the diagonal members.


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A pair of diagonal members are constructed at mid point at the fifth step to resist compression

force. These members efficiently balanced the forces created.

Lastly, a series of members having 60mm in length are served to connect the bottom and the top

chords of two main facades. The members of the bottom stuck into I-beam and those on the top

rest well on the top chords at the same position with the vertical members. Diagonals are

constructed on the top to strengthen the connection. These members are served to resist torsion

forces.

Diagram 4.8.7 Fifth step of erection, the middle

diagonal members. Figure 4.8.1 Close up picture of the

connection of the middle diagonal

members.

Diagram 4.8.8 The connection of two main

facades. Figure 4.8.2 Close up picture of the core

element.


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Diagram 4.8.9 The construction of horizontal

members on the top.

Diagram 4.8.10 the diagonal members on the top.

Diagram 4.8.11 Bottom view. Diagram 4.8.12 Top view.

Diagram 4.8.13 Elevation drawing of the bridge.


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4.9 Final Bridge Test & Load Distribution

Bridge weight: 79g

Load Carried: 15.5kg

Efficiency: 3041

During the final bridge test, our bridge can withstand 15.5 kg and reach efficiency of 3041,

which is about 4 times compare to the 7th bridge we made. This is due to the presence of

more tension force than compression force especially the part where load being located.

Tension force is used to resist the compression force of the load. The middle part of the

bridge encounters a lot of tension force that is good in preventing the bridge from breaking.

The compression force of the upper part is evenly distributed among the vertical and

diagonal truss. Some of the vertical and diagonal members also help in tension force. The

tension force in this final bridge is more than the compression force comparing to previous

design. That’s why the efficiency is far away beyond our expectation, which can carry about

15.5 Kg. The bridge is not left to dry that long until become fragile. Therefore, enhancing

the stiffness of the bridge.

The bridge breaks in the core horizontal element only, and it bounces off after broke. The

other member do not break either, this showed the force among the members is in

equilibrium.

Diagram 4.9.1 The load distribution of tension and compression force (internal)

Figure 4 .9.1 Final bridge test (before break) Figure 4.9.2 Final bridge test (after break)

Compression

Tension


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4.10 Calculation of Distribution of Forces for Final Bridge


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CHAPTER 5: Reference

Patent US529220 - Truss-bridge.(1894, November 13). Retrieved Oct 1, 2015, from

http://www.google.com/patents/US529220

Ching, Francis D.K (2008) Building Construction Illustrated Fourth Edition. New Jersey: John

Wiley & Sons, Inc.

Lamb, Robert, and Michael Morrissey. "How Bridges Work" (01 April 2000). Retrieved Oct 1,

2015, from http://science.howstuffworks.com/engineering/civil/bridge.html

http://www.google.com/patents/US529220

http://science.howstuffworks.com/engineering/civil/bridge.html


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CHAPTER 6: INDIVIDUAL CASE STUDIES

6.1 Case Study 1 (Chan Pin Qi)


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6.2 Case Study 2 (Lim Yee Qun)


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6.3 Case Study 3 (Te Li Teng)


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6.4 Case Study 4 (Liew Qiao Li)


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6.5 Case Study 5 (Woo Wen Jian)


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Education

Building Structure Project 1