fettuccine truss bridge report

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FETTUCCINE

TRUSS BRIDGE

PROJECT I ARC 2523 BUILDING STRUCTURES SCHOOL OF SCIENCE, ARCHITECTURE AND BUILDING DESIGN TUTOR:MR. ADIB FUNG HO YENG 0319473 IVY VOO VUI YEE 0319534 LEONG VUI YUNG 0320362 LIONG SHUN QI 0315942 LO JIA WOEI 0318585

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TABLE OF CONTENT PAGE NUMBER 1. Introduction

1.0 General purpose of study 3 1.0 Report preview 3 1.1 Learning Outcomes 3

2. Methodology

2.0 Precedent Study 4 2.1 Materials and Equipment Testing 4 2.2 Model Making 4 2.3 Structural Analysis 4-5 2.4 Model Testing 5 2.5 Bridge Efficiency Calculation 5 2.6 Working Schedule 6

3. Introduction of truss 3.0 Introduction of Warren Truss 7-9 3.1 Precedent Studies 10-12

4. Materials & Equipment 4.0 Equipment 13-14 4.1 Materials Strength Study 15-21

5. Bridge Testing 5.0 Test Bridge 1 Analysis 22-23 5.1 Test Bridge 2 Analysis 24-25 5.2 Test Bridge 3 Analysis 26 5.3 Test Bridge 4 Analysis 27 5.4 Test Bridge 5 Analysis 28 5.5 Test Bridge 6 Analysis 29 5.6 Test Bridge 7 Analysis 30-31 5.7 Test Bridge 8 Analysis 32 5.8 Test Bridge 9 Analysis 33 5.9 Test Bridge 10 Analysis 34

6. Final Bridge 35-44

7. Conclusion 45

8. Case Study 46-66

9. References 67

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CHAPTER 1

INTRODUCTION 1.0 Introduction

In a group of 5, we are required to design a roof truss using fettuccini as construction material, then tested for how many loads it can carry. The aim of this project is to develop an understanding of how forces are going on in a building structure, such as the tension and compression force. To achieve that, we are required to conduct a precedent study of a bridge to learn and analyze about how the connections, arrangements, and orientation of its truss members affects the strength of the bridge. With the research and understanding, we are required to apply them on the design the truss of our bridge. The requirements of the bridge are to not exceed a maximum weight of 70g and must have a clear span of 350mm. The bridge must carry at least 10 kg of load and we are required to analyze the reason of its failure and calculate the efficiency of the bridge using the formula:

bridge of Weight

Load MaximumE,Efficiency

1.1 Report preview

The report started off with a precedent study carried out on a truss bridge. Analyze the load distribution and how it affects its member. The report also recorded down the several designs we had tried out before the deciding on the final design. These test bridges were improved and developed further based on previous test results and analysis to increase its efficiency. A set of analysis regarding the strength of the bridge structure and its reason of failure had been done. Individual case studies calculations are attached at the end of the report.

1.2 Learning Outcomes At the end of this project, we are able to:

Evaluate, explore and improve attributes of construction materials.

Explore and apply understanding of load distribution in a truss.

Evaluate and identify tension and compression members in a truss structure

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CHAPTER 2

METHODOLOGY 2.0 Methodology

To complete this project, we have carried out following methods in the process of researching and building a suitable truss bridge:

2.1 Precedent Study

By looking through precedent studies, we will have a better understanding on the types of trusses available. We had chosen Warren Clem Lowell Road Bridge as our case study to refer to and help us along the analysis of our model bridge. We focused on the connection of joints and the arrangement of members, as well as whether it was aesthetically pleasing. This bridge has inspired us for our final fettuccine bridge in terms of design and truss member arrangement. Further exploration and findings will be elaborated in the Precedent Study section later.

2.2 Materials and Equipment Testing

Phase 1: Physical properties of material

We first understand how forces act on the fettuccine. We tested the tension and compression strength of the fettuccine. Physical properties of fettuccine are important to build the bridge so that it can carry the maximum load. We stick several pieces of fettuccine and put a load at the centre to test it, starting to test from the horizontal faces then vertical faces. From the experiment, we found that fettuccine is weak in compression and strong in tension.

Phase 2: Brands and types of material

After we had tested the physical properties, we continued testing different brands of fettuccine, which are San Remo and Kimball. We also did experiment on the types of fettuccine, whether original fettuccine or spinach fettuccine has the stronger strength. It is important to test different brands and types of fettuccine to observe their strength when subjected to loads. After the experiment, San Remo spinach fettuccine is the finalized brand and type of fettuccine that we have chosen as it is the strongest compared to others. Our analysis will be recorded under the chapter “Material Strength Study”.

Phase 3: Adhesive

The adhesive also plays a huge role in building the bridge, as what we used to bond the fettuccine together would affect the overall strength of the structure. There are various choices of glue with different characteristics available, so it is obviously crucial to choose the appropriate adhesive. We had experimented and observe how various types of adhesive are being used and how they affect the joints. We settled on super glue at the end.

2.3 Model making

Upon understanding from our precedent study, we started to sketch out a possible design for an efficient perfect truss bridge. We had to be sure to design for a clear span of 350mm bridge (leaving 40mm on the sides to hoist up on the table. Once we agree on the design, we drafted it out on AutoCad and the drawings were plotted and printed in 1:1 scale to ensure precision in

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the model making process. Then, we also did quality check on the packets of fettuccines and sorted out the straight one and the twisted one.

2.4 Structural Analysis

Structural Analysis is the determination on the effects of load on the bridge and its members by calculation. The truss’s strength was analyzed by understanding which members were used for tension purposes and which for compression. Based on the methods practiced by truss analysis exercises, the structural analysis of the bridge will be done by the same way.

2.5 Model Testing

Completed models are being placed aside to allow the glue dry properly (at least 5 minutes) before testing. To test the bridge, we set two tables (of equal height) exactly 350mm apart, and put the bridge in the middle. Before testing, we must first weigh the bridge to see how far above or below the 70g limit given. After documenting the weight, the S hook and bucket are weighed to calculate the total weight of the load that will be hung on the bridge. The S hook is placed in the middle of intermediate member to ensure the load distribution is even. The bucket handle is then hook on the S hook. The bucket does not elevate too far above from the ground to avoid the bucket break when falling down. We had also prepared 100g load, 200g load and 500g load before the testing. We started to record video as we started to test the bridge. This is our way to check more accurately where the problem is after testing. As load is being added, the bridge is checked for any deformities. As the bridge starts to deform, the points where the bridge are the weakest will be noted down. We then continue adding load until the bridge broke. The results and problems are being recorded for further improvement. Based on the records, the strength of the bridge is studied and the design is modified accordingly by enhancing its weak points. We strengthen the parts that deformed quickly and parts that snapped upon heavy loads are applied to the bridge. Every time a draft model could not hold the required weight, we analyzed the reason behind it and improved upon it with the next one until the bridge can hold a desirable loads as well as the mass is lesser than 70g.

Fig. 2.1, 2.2 and 2.3: Process of the crafting of the bridges.

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2.6 Bridge Efficiency Calculation

Efficiency of the bridge is calculated after it is tested to fail by using the formula below.

Efficiency, E = (Maximum load) Mass of bridge

2.7 Working Schedule

Date Task

11th April 2016 Case study research

18th April 2016 Testing of the strength of the materials (brands and types of fettuccine) and different adhesives

25th April 2016 Initial designing of truss

25th April 2016 Confirmation of design and crafting of bridge #1a

25th April 2016 Testing of bridge #1a

25th April 2016 Modifying bridge #1 and construction of bridge #1

25th April 2016 Testing of bridge #1

30th April 2016 Construction of bridge #2


30th April 2016 Construction of bridge #3


6th May 2016 Modifying bridge #3 and construction of bridge #4

6th May 2016 Testing of bridge #4

7th May 2016 Construction of bridge #5












8th May 2016 Construction of final bridge

9th May 2016 Submission and testing of final fettuccine bridge

Table 2.7.1: Working Schedule

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CHAPTER 3

INTRODUCTION OF TRUSS 3.0 Introduction of Warren Truss

A truss is an assembly of linear members connected together to form a triangle or triangles that

convert all external forces into axial compression or tension in its members.

A bridge with truss is called a truss bridge, which is a load bearing superstructure that is

composed of a structure of connected elements forming triangular units. The elements may be

stressed from tension, compression forces or sometimes both in response to dynamic loads.

Figure 3.1: Components in a truss bridge

Tension and compression force is a happening in a truss bridge. Tension is a force that acts to

stretch or pull the structure. Meanwhile, compression is a force that acts to squeeze or push the

structure. They affect and damage the structure of the bridge varying from different weight of

loads. Lateral wind forces is also a force which acts on the bridge.

Figure 3.2: Tension force and compression force act on truss

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Figure 3.3: Direction of compression and tension force act on a structure

A truss designed for uses must safe and stable. If the force that applies on the truss has

exceeded its load bearing capability, it goes buckling or snapping.

Figure 3.4: Buckling

Buckling happens when the compression force has exceeded its load bearing capability.

Figure 3.5: Snapping

Snapping happens when tension force exceeds.

Different members in the truss bridge experiences different kind of forces, therefore the

designer and engineer have to determine the structural strength and solve it by using different

truss design.

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The best way to deal with these powerful forces is to either dissipate them or transfer them.

With dissipation, the design allows the force to be spread out evenly over greater area, so that

no one spot bears the concentrated brunt of it.

WARREN TRUSS

Figure 3.6: Warren truss

The history of warren truss can be traced back to Italy because there are no exact records on

what time the first warren truss was used. The first truss bridge was built in the mid 1800s by

Alfred Neville in France. His design used isosceles triangles vs the equilateral triangles that were

used by James Warren in 1848.

The warren truss uses equilateral triangles to spread out the loads of the bridge. This is different

from Neville truss, which uses the isosceles triangles. The equilateral triangles minimize the

forces to only compression and tension. Let say, if an object moves across the bridge, the forces

for a member change from compression to tension. This would occur mostly for the members

near the car or train.

When the load is focused on the middle of the bridge, just like our fettuccine bridge with a point

load, pretty much all the forces are larger. The top and bottom chord are under large forces,

even though the total load is the same. Meaning to say, if a fettuccine bridge need to hold more

weight, then spreading out the forces across the top of the bridge is mandatory and for a real

life warren truss bridge, the forces should be much localized and should not be spread out along

the bridge. The designer and engineer should decide and calculate the strength of each member

of the bridge and build accordingly.

Figure 3.7: Force act on warren truss

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3.1 Precedent Study

Clem Lowell Road Bridge

Figure 3.1: Clem Lowell Bridge

The Clem Lowell Bridge served the citizens of Carroll County, Georgia for more than 70 years

but, over time and from increased use, the steel truss was in need of repair in order to bring it

up to today’s standards. Carroll County officials closed the bridge for four months in 2008 to

perform the much needed maintenance and repair. Additionally, the County lowered the load

limit on the bridge to below 3 tons. The completed repair work lasted for approximately one

year until a heavy truck crossed the bridge, breaking the seal on the concrete slab. The county

wanted the new structure to resemble the original structure and contacted Health & Lineback

Engineers to design the new abutments. They worked with U.S.Bridge on the new bridge design.

As a result, a 130’ x 28’ U.S.Bridge Cambridge Flat model was selected as the structure that best

replicated the old Clem Lowell Road Bridge while also providing the current load rating

standards and structural integrity. This is a warren bridge with a sufficient rating 18 out of 100.

Length of largest span 61.7ft

Total length 101.7ft

Style Warren Truss

Finish Weathering steel

Decking Concrete

Decking width 16.1ft.

Average daily traffic 510

Table 3.2.1: Information of Clem Lowell Bridge

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Installation of Clem Lowell Bridge (Figure 3.2, 3.3, 3.4, 3.5)

Figure 3.6, 3.7: Completed Clem Lowell Bridge

Figure 3.8: Clem Lowell Bridge is a warren truss with vertical

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The Clem Lowell Bridge makes use of a number of connecting joints.

1. Connections of portal bracing members

2. Gusset plate connections

3. Connection of multiple diagonal members

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CHAPTER 4

EQUIPMENT AND MATERIAL ANALYSIS 4.0 Equipment

Table 4.1: These were the tools we used during the model making

1. Pen knife and Scissors :

Pen knife and scissors used in the model

making process to cut the fettuccine into

specific dimension needed.

2. Rulers

Used to measure the fettuccine members,

clear span of the bridge and the total length of

fettuccine accurately.

3. Kitchen Balance

Measuring equipment for weighing the

fettuccine to ensure it did not exceed the

restricted weight by following the brief given.

(70gm)

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4. S-Hook

Used as connection between fettuccine bridge

and the load (weights) at the center part of the

bridge.

5. Bucket

Equipment used to hold the loads (water)

during the load testing.

6. Phone Camera and Tripod Stand

Used to document and record the working

process and the testing of bridges.

7. Calculator

Equipment used to solve all the calculations

accurately during the model making.

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4.1 Material Strength Study

4.1.1 Adhesive Types

Experiment of different types of glue were carried out before starting design the fettuccine

bridge in order to obtain the best result for our connections :

Table 4.2. : Comparison between different types of adhesive.

(Ascending order from strongest adhesive properties to weakest)

Types of Adhesive Analysis

Super Glue

(Elephant brand)

Fast bonding time about 10 seconds (slower than 3-second glue)

High bonding strength High efficiency Strength of bonding strong and lasting for

few days after built Clean connection of joints Easy to apply

502 (3-Second Glue)

Fastest bonding time (about 3 seconds) High connection bond strength High tendency of cracking after few days.

(Fettuccine brittle faster than other glue) High efficiency Clean connection of joints Easy to apply

UHU Glue

Slow bonding time (about 40 seconds) Easy to apply Average connection bond strength Average efficiency

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Hot Glue Gun Troublesome to use (easy to get hurt) High connection bond strength Finishing are bulky and messy Heavy compared to other glue (increase

bridge weight)

White Glue Long bonding time taken Low connection bond strength Low efficiency

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4.1.2 Adhesive Strength Test

Table 4.3: Comparison adhesive strength of different types of glue by using same type of

fettuccine (San Demo regular type fettuccine) and applied on whole fettuccine within one day.

According to the data recorded in the table above, it shows that 502 (3-second glue) have the

highest efficiency of adhesive strength among all of the other glue. Besides, the result showed

that UHU glue have same adhesive strength efficiency with Super glue (Elephant glue).

Type of

Glue:

Clear

Span

(mm):

Length

(mm):

Layer

of

pasta:

Weight

Sustained (g):

Weight of

fettuccine (g):

Efficiency

Super

glue

(Elephant

glue)

15 25 5 1016 9 112.89

502 (3-

second

glue)

15 25 5 1016 8 127

UHU glue 15 25 5 Cannot sustain 416 9 0

Hot glue 15 25 5 1016 9 112.89

White

glue

15 25 5 416 9 46.22

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Table 4.4: Comparison adhesive strength of different types of glue by using same type of

fettuccine (San Demo regular type fettuccine) and applied on whole fettuccine more than one

day.

After fettuccine layers left to settle for more than one day, we carried out another test to

examine whether the fettuccine layer can sustain more or less load than what it could be that

shown in table 4.4. From the test result, it shows that Super glue( Elephant glue) could sustain

even more weight, while the 502 (3-second glue) and UHU glue sustain less.

In conclusion, this two experiments prove that 502 (3-second glue) is the most suitable adhesive

media for our fettuccine bridge. It is due to the 502 (3-second glue) takes fastest bonding time

with just about 3 seconds compared to Super glue( Elephant glue). And it has high connection

bond strength and high efficiency that very close to Super glue( Elephant glue). While Hot glue

was not being accepted due to it is heavy than other types of glue , bulky and messy finishing

and troublesome to use. Moreover, the issue of 502 (3-second glue) with high tendency of

cracking and brittle faster than other glue after few days being overcome by our planning on

making the fettuccine bridge within a day before submission to ensure the best performance of

the fettuccine bridge.

Type of

Glue:

Clear

Span

(mm):

Length

(mm):

Layer

of

pasta:

Weight

Sustained (g):

Weight of

fettuccine

(g):

Efficiency

Super

glue

(Elephant

glue)

15 25 5 1040 9 115.56

502 (3-

second

glue)

15 25 5 1000 8 125.00

UHU glue 15 25 5 Cannot sustain 416 9 0

Hot glue 15 25 5 1000 9 111.11

White

glue

15 25 5 350 9 38.89

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4.1.3 Fettuccine Types & Strength Study

Strength test on fettuccine used for the bridge also being carried out to determine which brand

and type of fettuccine was the strongest to carry loads since it is our main construction material.

This is an important part to test our main construction material before we start making the

physical model.

Table 4.5: Fettuccine brands and the weight they could sustain under same type of glue and

layers of pasta.

Fettucci

ne

brands

and

types

Type of

Glue:

Clear

Span

(mm):

Length

(mm):

Layer

of

pasta:

Weight

Sustained

(g):

Weight of

fettuccine

(g):

Efficiency

San Demo

regular

type

502 (3-

second

glue)

15 25 5 1016 8 127.00

Kimball

regular

type

516 6 86.00

San Demo

spinach

type

1150 9 127.78

San Demo

regular

type

Super

glue

(Elepha

nt glue)

15 25 5 1016 9 112.89

Kimball

regular

type

516 7 73.71

San Demo

spinach

type

1150 9 127.78

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Image

Brand Types Max.Weight

Sustained (g)

within 5 layers

San Demo Regular type 1016

Kimball Regular type 516

San Demo Spinach type 1150

As table 4.5 illustrates, we can conclude that San Remo was our choice of fettuccine brands for

the final bridge. While the type of fettuccine chose for the final bridge was Spinach type of

fettuccine. It is because Spinach fettuccine has slightly higher efficiency than San Demo original

type fettuccine with just 1 gram heavier than original type.

After decided San Demo Spinach type fettuccine as our main constructed material, a test in the

way we layered the fettuccine was carried out to find out the strongest type of layering which

can sustained highest load.

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Table 4.6: The test results of different layers of fettuccine and the load each could sustain.

Structural

members

Length

of

fettucci

ne (cm)

Clear

span

(cm)

Load

sustained,

horizontal

facing (g)

Weight

of

fettucci

ne (g):

Efficiency

5 layers 25 15 1300 9 144.44

4 layers 25 15 750 6 125.00

3 Layers 25 15 516 4 129.00

C-beam 25 15 416 4 104.00

L-beam 25 15 Cannot sustain

416

2 0

3 Layer I-beam 25 15 516 5 103.20

4 layer I-beam 25 15 1000 6 166.67

5 Layer I-beam 25 15 1000 8 125.00

6 Layer I-beam 25 15 1250 11 113.64

8 Layer I-beam 25 15 1616 22 73.45

Based on the table above, it is clear that four layer I-beam has the highest efficiency and follow

by five layer structure then is three layer structure. After evaluation, we decided to use four

layer I-beam and three layers structure as three layer structure has slightly lower efficiency than

five layer structure but with just half of the weight of five layer structure.

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CHAPTER 5

BRIDGE TESTING 5.0 Test Bridge 1 Analysis

Date: 25 April 2016

Figure 5.1, 5.2

Efficiency

= Load / Weight of the bridge

=1800g / 115g

=15.65

Warren Truss

Bridges Clear Span:35cm

Weight: 115g

Total length: 45cm

Test Load 10-Second Test

1 500g Ok

2 1000g Ok

3 1200g Ok

4 1400g Ok

5 1600g Ok

6 1800g Ok

7 2000g Not ok

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Failure

Figure 5.3, 5.4, 5.5, 5.5 (from left)

Using Sam Remo Spinash Fettucini with super glue for the bridge after we have done our all

experiments. In the other way, we are going to chose to do a warren truss for our first bridge.

After figuring and testing up different types of member and their strenght, we decided to use 4

layer I-beam as our base and the columns, 3 layers for our top and secondary members as we

found that although the efficiency for both of them are not the higher one but we used these

members is because it can carry a certain weight and achieve a standard effiecency level. We

designed a ‘X’ at the middle bottom part of the bridge to hangthe S hook. At last, the bridge

failed at some of the connection parts and the base part due to imperfect connections and too

thin to carry the loads.

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5.1 Test Bridge 2 Analysis

Date: 30 April 2016

Efficiency


=170g/100g

=17

Figure 5.6

Figure5.7

Figure 5.8

Failure

Warren Truss


Weight: 100g

Total length: 45cm


1 500g Ok

2 1000g Ok

3 1200g Ok

4 1400g Ok

5 1600g Ok

6 1800g 7s

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Figure 5.9

Figure 5.10

For the second testing, we still remained the 4 layer I-beam at the bottom, but the bottom was then

rest on the end of the beams at the end of the column and the beams will rest on the table, means

that the bottom was lifted from the table and didn’t touch the table directly. We believed that this

way can helped the forces transferred in a more proper way. We had rearranged all the orientation

of the fettuccini which are lying in vertical orientation because we found that placed the fettuccini

vertical orientation could effort more forces than normal. Furthermore, we also picked out some

necessary vertical members to reduce the weight. For the failure, the bottom part, beside the “X”

part broken first then following by the rest of the members.

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5.2 Test Bridge 3 Analysis Date: 30 April 2016

Efficiency


=1500g/79g

=18.99

Figure 5.11

Figure 5.12, 5.13, 5.14

This time we changed our hooked place from bottom to the top. We wanted to figure out was the

bottom or the top will be more suitable to hook. We also enlarged the “X” part and rested on the

top part. Design became simpler due to the weight. Lastly, the big X broken as it is too big and just

rested on the top bream, it may disturbed the forces transmition.

Warren Truss


Weight: 79g

Total length: 45cm


1 500g Ok

2 1000g Ok

3 1200g Ok

4 1400g Ok

5 1500g Ok

6 1600g Not ok

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5.3 Test Bridge 4 Analysis Date: 6 May 2016

Figure 5.15

Figure 5.16, 5.17

Efficiency


=2200g/70g

=31.43

Because we will hooked from the bottom, so our bottom should be thicker than the previous failure

bridge. So, we changed the bottom structure members from 4 layers I-Beam to 8 layers I-Beam so

that it could enough to effort the load. We also changed the ‘X’ hooked part become “H” in 8 layers

I-Beam and they are rested on the base column so that they can transferred the load to the base and

let the base transferred to the other members or directly to the surface. We cut all the extra

fettuccini from 2 or 3 layer to 1 layer as they just act as a support or secondary member due to the

overweight problems.


1 1000g Ok

2 1500g Ok

3 2000g Ok

4 2200g Ok

5 2400g Not ok

Warren Truss


Weight: 70g

Total length: 45cm

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Date: 7 May 2016

Figure 5.18, 5.19, 5.20

Efficiency


=3400g/88g

=38.64

Compare to the others, our bridge only can carried 2 kg (highest record) until this stage. So, we

decided to deduce the width and the height of the bridge. We knew that, height and width might

affect the streghten of the bridge just like we use 2 slices of fettuccini to tested out will the shorter

or longer piece more sustainable and we come out will the shorter will better when placed in vertical

orientation but longer will better when placed lying horizontally. The ‘V’ shape members we add

more so that it can helps to divide the forces.

Warren Truss


Weight: 88g

Total length: 45cm


1 1000g Ok

2 1500g Ok

3 2000g Ok

4 2200g Ok

5 2400g Ok

6 2600g Ok

7 2800g Ok

8 3000g Ok

9 3200g Ok

10 3400g Ok

11 3600g Not ok

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Date: 7 May 2016

Figure 5.21, 5.22, 5.23 Efficiency


=4500g/83g

=54.22

Still remaining the 8 layers I-Beam and the ‘H’ hooked at the middle. This time, we added the “V”

structure to 8. We realized that, the “V”s were really worked well to distribute the forces properly.

The most important part to let the “V” performed well was the connections. The connections has to

rest and connect between the base beam and the columns, so that the forces will only passed to the

columns and the beams. For this failure, only the “H” hooked broken, the whole structure is still

remained perfectly. From this point, we tried to asking ourselves, was the structure too strong or we

didn’t design all the structure members to distribute the forces properly.

Warren Truss


Weight: 83g

Total length: 45cm


1 1000g Ok

2 1500g Ok

3 2000g Ok

4 2500g Ok

5 3000g Ok

6 3500g Ok

7 4000g Ok

8 4500g Ok

9 5000g Not ok

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Figure 5.24, 5.25, 5.26

Warren Truss


Weight: 91g

Total length: 40cm


1 1000g Ok

2 1500g Ok

3 2000g Ok

4 2500g Ok

5 3000g Ok

6 3500g Ok

7 4000g Ok

8 4500g Ok

9 5000g Ok

10 5500g Ok

11 6000g Ok

12 6500g Ok

13 7000g Ok

14 7500g Ok

15 8000g Ok

16 8500g Not ok

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Efficiency


=8000g/90g

=88.89

Failure

Figure 5.27, 5,28, 5.29

This bridge failed due to the incorrect position of s hook located and week top beam used.

After experiments many of the bridges, we found that the more the warren truss members, more weight can be carried. So, we decided to add structural truss members from 10 into 13 on our next design. We also realized the problems of balancing the forces throughout the overall structure. The trusses need to be upright and symmetrical to another side. Hence, equilateral triangle was used in the design to distribute force equally. Moreover, proper design of fettuccine use is important to solve overweight problem.

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Figure 5.30, 5.31, 5.32

Efficiency


=11200g/87g

=128.74

13 trusses members of warren Truss show the best efficiency among all the test bridges. The main

failure of this bridge is the main supportive core. The separated 8 layer I beam that carry s hook

failed after 11 kg but the whole structure is still remain strong and steady. Moreover, over weight

was one of the main problems.

Warren Truss


Weight: 87g

Total length: 40cm

Test Load

1 1119g

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Figure 5.33, 5.34, 5.35

Efficiency


=11883g/81g

=146.7

Using the same structural and material as 10th test bridge, but only shorten the main core and also

re-position to center part. As a result, the shorter the core, the stronger it is.

Improvement:

Decreasing all the necessarily structure and thinner the main structure from 8 layer I beam to 6

Layer I beam. Beside that, replace the bracing and connecting members from Sam Remo Spinash

Fettucini to the Original Sam Remo Fettucini.

Warren Truss


Weight: 81g

Total length: 39cm

Test Load

1 11883g

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Date: 8 May 2016

Figure 5.36, 5.37, 5.38

Efficiency


=9374/81g

=115.73

First of all, we have successfully design a 70g warren bridge. Due to the limited weight,by mixing of

fettuccine and decrease the core members into 4 layer stack beam and re-position of center core

have improved the efficiency of the truss bridge. Whereas, this bridges sustain until it maximum

weight and fail at the top and bottom main beam.

Warren Truss


Weight: 70g

Total length: 39cm

Test Load

1 9374g

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CHAPTER 6

FINAL BRIDGE

6.1 Amendments

The final bridge design is same as the 9th fettuccini bridge we made previously as its efficiency is the

highest among the bridges we made that withstand 10kg. However, the previous bridge can only

withstand 9.3kg. This might caused by the decreased weight compared to the best bridge. 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 within 70g.

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6.2 Top 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 (8-layers I-Beam as the

top main diagonal member and double layer members as horizontal member), 7th bridge (4-layers

member as the top main diagonal member and single layer member as horizontal member), we

found out that the main supporting members that withstand the highest weight among other

members is the top main diagonal member, but it is not necessary to use the 8 layers I-Beam as it is

quite heavy for diagonal members. However, the horizontal member is a must to add in but single

layer member is enough to support both side of members.

Figure 6.1 6th bridge (using 8-layers I-Beam as main diagonal member)

Figure 6.2 7th bridge (using 4-

layers member as main

Figure 6.3 Top chord of final design diagonal member)

Figure 6.4 Top view of final design

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

reduce the weight of the whole bridge. After several tests on the types of beam, we concluded that

3-layers member is enough to withstand the force. For the horizontal, we decided to use single layer

member to reduce the weight of the bridge.

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6.3 Bottom Chord

Base is the most important among the whole structure as it carries most of the load and transfers

the load to the top. After all experiment for the base structure, we concluded that heavier base

support more load. We did try 8-layers I-Beam as our base, it did withstand the highest load but it is

quite heavy and exceed our limitations. So, we decided to change it to 6-layers I-Beam. For the

horizontal element, we use single layer member to support both side of the beam.

Figure 6.5

Figure 6.6

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6.4 Core Horizontal Element

Figure 6.7 Perspective view of core horizontal Figure 6.8 Elevation of core horizontal element

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

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

force from the load. Therefore, the core horizontal element is amended into 6-layers member as it

provides more stiffness for the load to fix in its direction. The core elements sit on the bottom chord

as it direct transfer the load to the nearest and strongest member (Bottom Chord). The two

members have been put near each other so that the core horizontal can fit the S hook accurately.

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6.5 Vertical & Diagonal Truss

The diagonal and vertical members form the truss web, and carry the shear force. Individually, they

are also in tension and compression, the exact arrangement of forces is depending on the type of

truss and again on the direction of bending. In our truss bridge, the vertical members are in tension

and the diagonals are in compression. After comparing the 7th bridge (without vertical) & 8th bridge

(with vertical), we found that the vertical members did helped to carry the tension force from the

top and bottom. Besides that, the diagonals should be placed inside both top and bottom members

so that they can help to carry the compression force instead of putting outside.

Figure 6.9 7th bridge , 6.10 8th

bridge

Figure 6.11 vertical member,

6.12 diagonal member

Amendments are made in the

trusses as well. Adding more

diagonals and verticals help in

withstand more loads. These

members do not need to have

lots of layer as they act as

aiding members.

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6.6 Joint

A :

Both side of the bottom part of diagonal bracing cut precisely and lay on the base structure of

Fettuccine bridge with butt joint. And, both diagonal bracing attach to each other in order to

distribute the force equally.

B :

Both left and right top part of diagonal bracing cut precisely and joined with butt joint to the top

part of vertical member. It formed a equilateral triangle structure between the top and base of

fettuccine bridge. The rigidity of equilateral triangle structure provide stability and strength to the

force acting on the bridge.

C :

The bottom part of diagonal bracing cut precisely and lay on the end part of the base structure of

the Fettuccine bridge with butt joint.

A

B

C

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The top and bottom joists are placed between its perspective beams to prevent the bridge from

shearing and twisting from external forces. The edges of the joist are inserted into the beam beside

so that they can distribute the force evenly.

Horizontal hooked member of the fettuccine bridge is simply laid perpendicularly on the base 6 layer

I-beam structure. This horizontal hooked member (6 layer I-beam) function as the load distribution

member to channel and balance the downward loads along the whole fettuccine bridge.

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6.7 Final Bridge Test

Figure 6.13

Bridge weight : 70g

Load carried : 10.5kgDuring the final bridge test, our bridge can withstand 10.5kg and reach

efficiency of 150, which is about 5 times compared to the 7th bridge we made. This is due to the

presence of more tension force than compression force especially the part where the 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.

Green line : Tension

Red line : Compression

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6.8 Failure Analysis

In our final bridge model testing, the centre of the base where the S hook put on is the first part to

break. It caused the base breaks afterwards. We concluded that our structure is quite useful to

withstand the force. We realized that the parts that broke on the bridge were completely on the left

side and also the centre of the long span of the base that distributed the entire load to the base. The

bridge started to buckle after 4 minutes and as we added more weight to it, we could see the bridge

slowly bending and falling apart.

Test Result:

Effectiveness of = Load /Weight of bridge

= 10500g /70g

= 150

Figure 6.14

Figure 6.15

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6.9 Final Drawing Calculation

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CHAPTER 7

CONCLUSION Throughout this project, we had constructed a total number of 11 fettuccine bridges includes the final test model. We had experimented all of them with many factors such as types of beams, orientation of members, design of trusses and ways to limit the weight of the bridge. We then chose the best result to build our bridge to make it stronger to withstand more loads. Other than understanding how those members work, we also learnt how important is tension force and compression force were in making the bridge more effective. On top of that, we understood the importance of the diagonal bracing member. These members are strengthen using double layered beams. The precision of each connecting joints were achieved as we had built the bridge based on the computer aided drawing we had prepare. Each connecting point is milled evenly using sand paper to prevent imperfect connecting joints. Upon understanding, our final model achieved the highest efficiency among the previous bridges model which we have done. An efficiency of 150E is achieved withstanding a total load of 1050g and its weight 70g. In conclusion, it has been a great experience to construct a bridge that can withstand heaviest load with the minimum weight using fettuccine. We are lucky to study the strength of the pasta and how can it join to get the best results. Although the process was long and tedious, requiring lots of patience putting the whole thing together, but it never fail to amaze us how fettuccine is able to withstand load. We really enjoyed the whole process.

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CHAPTER 8

CASE STUDY

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CASE 1 BY FUNG HO YENG 0319473 page 1

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CASE 2 BY LIONG SHUN QI 0315942 (page 1)

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CASE 3 BY LEONG VUI YUNG 0320362 (page 1)

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CASE 4 BY LO JIA WOEI 0318585 (page 1)

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CASE 5 BY IVY VOO VUI YEE 0319534 (page 1)

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CHAPTER 9

REFERENCES 1. Clem Lowell Road Bridge. (n.d.). Retrieved May 5, 2016, from

http://bridgehunter.com/ga/carroll/clem-lowell/

2. SRT251 Group 2. (n.d.). Retrieved May 5, 2016, from http://srt251group2-blog.tumblr.com/

3. SiteSolutions News. (n.d.). Retrieved May 5, 2016, from http://www.conteches.com/our-

company/news/ctl/viewitem/mid/2784/itemid/135

4. What is Warren Truss? (n.d.). Retrieved May 5, 2016, from

http://www.innovateus.net/transportation/what-warren-truss

5. Warren Truss. (n.d.). Retrieved May 5, 2016, from

http://www.garrettsbridges.com/design/warren-truss/

http://bridgehunter.com/ga/carroll/clem-lowell/

http://srt251group2-blog.tumblr.com/

http://www.conteches.com/our-company/news/ctl/viewitem/mid/2784/itemid/135

http://www.conteches.com/our-company/news/ctl/viewitem/mid/2784/itemid/135

http://www.innovateus.net/transportation/what-warren-truss

http://www.garrettsbridges.com/design/warren-truss/

fettuccine truss bridge report

Engineering