SCHOOL OF ARCHITECTURE, BUILDING & DESIGNResearch Unit for Modern Architecture Studies in Southeast AsiaBachelors of Science (Honours) (Architecture)

Building Structures (ARC 2523)Prerequisite: Building Construction 2 (ARC2213)

Project 1Fettuccine Truss Bridge

Tutor: Mr. Adib

Astari Razak 1101P11983Celine Tan Jean Inn 0303669

Feiven Chee 0312004Tang Hui Ying 0312089Hong Si Mun 0312643

Wong Jia Xin 1101G13277

Table of Content

1. Introduction 1.1. Aim of Objectives1.2. Perfect Truss1.3. Scope of Study1.4. Limitation

2. Methodology

3. Precedent Study3.1 History and Background3.2 Structure3.3 Construction

4. Equipment and Material Study4.1 Material Strength Study 4.1.1 Types of Fettuccine 4.1.2 Orientation4.2 Equipment Study

4.2.1 Glue Types4.2.2 Gluing Method

4.3 Model Making4.4 Working Schedule

5. Design Process5.1. Proposed Design - Part 15.2. Truss Analysis - Part 15.3. Proposed Design - Part 25.4. Truss Analysis - Part 25.5. Proposed Design - Part 35.6. Truss Analysis - Part 35.7. Final Design

6. Model Testing6.1. Observation6.2. Efficiency

7. Analysis7.1. Structural Analysis7.2. Failure Analysis7.3. Design Modification

8. Conclusion

9. Appendix

10. References

1.0 Introduction

1.1 Aim & Objectives

Aim

For this project, we were to design a fettuccini bridge with the requirements of a clear span of

600mm length and a maximum of 150g in weight. Our aim was to construct a bridge with high

efficiency with minimal material weight and high load.

Objectives

To develop and be able to apply our understanding of tension and compressive strength of

construction materials

To develop our understanding of force distribution in a truss

To design a high efficiency perfect truss bridge with high level of aesthetic value

1.2 The Perfect Truss

Truss:

A structural member that is usually found in a framework used to support a structure. By definition,

a truss can be various structural frames based on the geometric rigidity of the triangle and composed

of straight members subject only to longitudinal compression, tension, or both.

Perfect Truss:

A truss is considered perfect if the condition 2J = m + 3 is fulfilled, whereas J is the number of

joints, m is the number of members. A perfect truss can be analysed to get the internal and external

member forces by using the three conditions of static equilibrium.

1.3 Project Scope

This project has the requirements of building a fettuccini bridge of a clear span of 600mm

length and a maximum of 150g in weight. Precedent studies were carried out to study a truss bridge

of our choice. The studies were then used to apply our understanding to the design of our bridge.

Structural analysis were carried out through the observation of load test to design several bridges and

then selecting the best bridge.

1.4 Limitations

This project limit us to design a perfect truss bridge with the use of fettuccini as our only

material, with any adhesive of our choice. The properties and method of construction of the

fettuccini bridge vary from our precedent study due to the size and nature of our material. Therefore,

the relationship of the fettuccini bridge and a life-size bridge of another material dissimilar.

In reality, a well constructed bridge is subjected to lateral loads, mobile loads and other

factors compared to a single point load which is used in our fettuccini bridge. As a result, the design

of our fettuccini bridge cannot be assumed to be functionally adequate for life size bridges.

2.0 Methodology

Precedent Study

Research on truss bridge design is carried out from books and internet to demonstrate existing bridge

styles and construction. Information of bridge’s connection, arrangement and orientation of truss

member is collected and applied to the bridge design.

Material Strength Testing

Material properties of fettuccine is tested with its tensile strength, compressive strength and bending

strength before model making in order to provide the material its highest performance.

Model Making

Only fettuccini may be used for construction of bridge and any adhesive may be used in jointing. A

2-D AutoCad drawing of all the elevations, including top layer, bottom layer, sides layer and cross

section is done before executing bridge model making. The drawing are printed out and used as a

pattern for the bridge design. This helps in cutting the fettuccine precisely tot the right size by laying

it down on the drawing and cutting it.

Model Testing

The bridge is centered on support and a “s” hook is hanged at the center of the bridge where load is

applied. Failure of the bridge is defined as the inability of the bridge to carry additional load and the

bridge is tested to fail.

Structural Analysis

Other than efficiency evaluation, it includes design drawing and calculations of internal force for

each member at every joint to further evaluate compression and tension members of the bridge

design. It also

3.0 Precedent study – The Sydney Harbour Bridge

3.1. History and background

Figure 1: The Sydney Harbour Bridge, Australia

The Sydney Harbour Bridge is a steel through bridge that spans across Sydney harbour which

consists of two railway lanes, eight vehicular, a bicycle lane and a pedestrian lane. It is the world’s

largest steel arch bridge with a total span of 1149 metres and an arch span of 503 metres, with the top

of the arch 134 meters above the harbour.

It was not originally thought of as an arch bridge. Dr Bradfield initially had a cantilever

bridge in mind to span the harbour. However, on a trip to New York he was inspired by the Hell Gate

Bridge and he realised the cantilever design was inferior to an arch for his proposed bridge.

3.1. Structure

The Sydney Harbour Bridge is a two-pin arch construction, made up of two arches side by

side, joined by horizontal cross-members. The arch is composed of two 28-panel arch trusses; their

heights vary from 18 m at the center of the arch to 57 m at the ends next to the pylons. The arch has a

span of 504 m and its summit is 134 m above mean sea level.

An arch bridge functions quite differently from a cantilever bridge (or beam bridge). In an

arch bridge, the vertical loads (live and dead loads) tend to flatten the arch and push out against the

abutments, creating both vertical and horizontal reaction forces. A beam bridge, by comparison,

exerts only vertical forces at its supports. This means that an arch must have significantly stronger

abutments than a beam bridge.

RHA = Horizontal reaction force at point A RVA = Vertical reaction force at point A

RHB = Horizontal reaction force at point B RVB = Vertical reaction force at point B

The truss of the arch of the bridge resembles the Pratt truss bridge design. The road deck is placed

underneath the arch, supported by tension members, and the deck ties the two ends of the arch

together, forming a tied arch. The tension tie takes the horizontal thrust, therefore, the

foundations need only to support the gravity loads on the bridge, which allow arches to be

used where there may not be otherwise suitable subsoil conditions.

Diagram 1: Showing the compression and tension forces acting in the bridge

The Pratt truss bridge designThe Sydney Harbour Bridge

The bridge structure is supported on four horizontal, cylindrical forged steel pins in the main

bearings, one at each end of the two arches. This allows the movement in the arch caused by

temperature variations and dynamic loading to be accounted for. The arch may rise up to 180 mm

due to heating during the day.

Abutments at the base of the pylons are essential to hold its span firmly in place and most

importantly, support the loads from the arch by taking the lateral thrust. However, the pylons

themselves have no structural purpose.

Figure 2: The massive hinges against the abutment, supporting the load from the arch.

The bridge structure rests on four large concrete skewbacks, two on each side of the shore.

The excavation made was directly into the solid sandstone. Each skewback is 40 feet wide (12.192

m), 90 feet long (27.432 m) and up to 30 feet (9.144 m) deep. The upper surface of these, for the

main bearings, is at an angle of 45° to take the main bearing casting.

Diagram 3: The thrust of the main arch below the main bearings is at an angle of 45˚.

Figure 3: Construction of Sydney Harbour Bridge’s main bearing.

Rivets (permanent mechanical fasteners) were extensively used in the construction of the

Sydney Harbour bridge, the largest scale use of rivets in any steel structure in Australia. The rivets

used were mild steel with UTS of 413-482 MPa and high shear strength. More than 6 million rivets

were used to assemble the bridge. Rivets with a head on one end were inserted into the plates and the

headless end is rounded over whilst the rivet is still very hot using a pneumatic riveting gun.

Diagram 5: When a hot rivet cools, it contracts imposing a compressive (clamping) stress on the plates. The rivet itself is

then in tension the tensile stress is approximately equal to the yield stress of the rivet material.

3.2 Construction

The tied arch is particularly difficult to construct, because the arch thrust is not resisted until

the road deck is constructed, but the road deck is unsupported until the arch is built.

Each half arch was built out from each shore supported on each of the main bearings to

prevent it from falling into the harbour.

Figure 4: The pneumatic riveter is operated by hand, and is used both inside and outside the workshops.

Diagram 4: Grain Flow in a rivet (right) machined from hot rolled bar. Note the sharp change in grain flow under the rivet head. Favourable grain flow in rivet (left) after inserting and rounding while hot, analogous to hot forging.

The southern head of the bridge was constructed a month ahead of the northern head to

ensure no errors would be repeated when constructing the northern head.

Figure 5: The early construction of Sydney Harbour Bridge.

4.0 Material and Equipment Study

4.1 Material Strength Testing

4.1.1 Types of Fettuccini:

Several types of fettuccini were tested for this project: i) Divella Fettucciniii) San Remo’s standard fettuccini

Results:

Before carrying out the experiment to determine the strength of different types of fettuccini,

we weighed one fettuccini and found that Divella Fettuccini is heavier than San's Remo Standard

Fettucini, which are 2g and 1g respectively. Besides, the surfaces of Divella Fettuccini is slightly

rounded compare to San Remo's Standard Fettuccini which causes the surface area for gluing is

lesser. Therefore, we chose San Remo's Standard Fettuccini as the material for bridge construction in

the concern of lighter in weight and flatten surface area for gluing.

Diagram 6: Example of each brand of fettuccini's surface

4.1.2 Orientation

Testing of different orientations of single fettuccini to determine which orientation would

have more strength to be put into the model design. This was done by placing the fettuccini evenly

over a gap of 100mm with pressure applied on both ends of it for support. Weights were placed in a

5g plastic bag that hung in the centre of the fettuccini member.

Surface of Divella of San Remo's Standard FettucciniFettuccini Surface /

Figure 6: Divella Fettuccini Figure 7: Standard Fettuccini

Figure 8: Placement of fettuccini over 100mm gap

Results:

Layer 1Load(g)/Face Horizontal Vertical

50 / /100 / /150 / /200 / /250 / /300 X /350 - /400 - X

Table 1 : Breaking point of horizontal and vertical orientation fettuccini members

The outcome of the test was that the horizontal oriented piece broke after 300g of weight

were placed and the vertical oriented piece broke after 400g of weight were placed. This concluded

that fettuccine has very little bending strength in horizontal orientation. Thus, horizontal member in

bridge design would consider using vertical facing.

4.2 Equipment Testing

4.2.1 Glue Types

The use of glue on surfaces of fettuccini that binds them together to resists separation and

create a rigid joints. The ability of different types of glue to bind the fettuccini, distribution of stress

across the joint and aesthetic value of workmanship will affect the efficiency of the bridge. Test of

glue is taken to get the efficiency and best result on connection.

Figure 9 : Horizontal Orientation Figure 10: Vertical Orientation

Figure 11: Glue Gun Figure 12: Adhesive Glue Figure 13: 3-Second Glue Figure 14: Epoxy Glue

Results:

Type of Glues Advantages Disadvantages

Hot Glue Gun - Easy to use - Joints too flexible- Low Effieciency- Weight increase significantly

Adhensive Glue (UHU) - Dries Quickly - Joints slightly flexible when dry

3-Second Glue

- Dries quicker than adhensive glue- Rigid Joint- Clean Joint- Highest Effiency

- Cracked joint found after Storing in room temperature- Expand and shringe occures

Expoxy Glue - Rigid Joint- High Effiency

- Takes longer time to dry- Require careful mixing- Messy

Table 2: Comparison of advantages and disadvantages each type of glues

From the above table, it can be concluded that different type of glue would have different

result on joint and aesthetic value in gluing. As result, 3-second Glue has the best result for rigid

joint with clean connection yet has fastest solidify time between connection which result higher

efficiency compare to other type of glues.

4.2.2 Gluing Method

After get the result of using 3-second glue that create a rigid joint and vertically orientation

able to carry greater load, a testing of different way of gluing method is taken to determine does the

gluing method affect the load carried and excessive weight of 2 layer of fettuccini. The experiment

was done by gluing the joint of fettuccini in two ways :

a) spot glue at intervals

b) glue entire length

Results:

Diagram 7: Spot glue at intervals Diagram 8: Glue entire length

Layer 2

Load(g)/Face Point Entire Surface50 / /100 / /150 / /200 / /250 / /300 / /350 / /400 / /450 / /500 / /550 / /600 / /650 / /700 X X

Table 3: Breaking point of gluing method in point and entire surface of fettuccini

As the result, both gluing method does not affect the load carrying as the breaking point of

both gluing method are the same. However, if a number of strands of fettuccine are to be used

together as single member, it is suggested to “spot” glue them at intervals of about 1cm as this will

provide adequate strength without adding excessive weight as compared to gluing the entire lengths.

4.3 Model MakingWe used different method to construct our bridge. Our very first bridge, we started by

drawing the bridge template on paper. Then we measure the length of each members then cut

accordingly. However, to increase the accuracy and efficiency of the other bridges, our next few

proposed bridges are first drawn in AutoCAD then printed out on paper. The length of the members

are then cut accordingly.

Figure 15: Segments of cut fettucinni

Figure 16: Assembling and gluing the pieces together.

As a group, we constructed the bridge together.

Figure 17: Holding the members together as dries

Figure 18: Group working together to build the bridge

4.4 Working Schedule

Date Tested TasksMarch 31, 2014 - Brief of Project 1, Fettuccine Truss Bridge

- Get tools and material before started prototype bridgeApril 7, 2014 - Study and Experiment of fettuccini strengthApril 9, 2014 - First bridge design test model making (based on case study)April 13, 2014 - 2nd bridge design test model making (Redo first model with lighter weight)April 16, 2014 - Tutorial with Lecturer regarding the design and load distribution of bridgeApril 18, 2014 - Third bridge design with improvements from second bridge

- Load carried is testedApril 21, 2014 - Discussion among group members by analysing the bridge design and load

distribution of each trussesApril 25, 2014 - Final bridge design making and testing

Table 4: Working schedule

5.0 Design Process

5.1 Proposed Design - Part 1

1ST BRIDGE DESIGN

Figure 19: First bridge design

2nd BRIDGE DESIGN

Figure 20: Second bridge design

The first and second bridges resemble the design from precedent study —Sydney Harbour

Bridge, relying support from the curved arch. The arrangement for bracing members and number of

layers of fettucine are tested from both designs. As the load is meant to hang at the bottom, there are

7 hanging members on each side connected to the arch to support the whole the structure. The

hanging members are designed in tension to favour the characteristic of fettucine. Not only

enchancing aesthetic value of the design, the width is reduced from 8cm to 1cm when going higher

as a way to reduce its weight, which in turn contributing to higher efficiency. However, the major

support from the arch is in compression which serves as the key drawback to this design.

5. 2 Truss Analysis - Part 1

Diagram 9: Truss analysis of 1st and 2nd bridge LOAD

CompressionTension

Diagram 10: Orthographic drawing of the 1st and 2nd bridge

1st Bridge Design 2nd Bridge Design

Length : 80cm Length : 80cmMax. height : 14cm Max. height : 14cmMax. width : 8cm Max. width : 8cmMass : 113g Mass : 0.103kg

Max. load : 1.48kgEfficiency : 21

Figure 21: Model testing of 2nd bridge Figure 22: 2nd bridge’s failure.

5.3 Proposed Design - Part 2

3rd BRIDGE DESIGN

Figure 23: Perspective view of the 3rd bridge

Figure 24: Facade of the bridge

After considering the existence of forces pushing outwards in the triangular shape of previous

designs, we intended to focus on achieving higher efficiency rather than on its aesthetic. Thus, a

normal truss bridge was experimented, with 5 panels on each side, spanning a length of 14cm on

each. The heavier structure with thicker layering is compensated with reducing length and height in

the design. Gathering information from precedent study and some other existing bridge, this design

follows a height to span length of 1:7. However, due to the 4-side structure, more bracing members

are needed to provide overall stability, which could be disadvantage in reaching higher efficiency.

5.4 Truss Analysis - Part 2

Diagram 11: Truss Analysis of 3rd bridge

LOAD

CompressionTensionCompressionTensionCompressionTension

CompressionTension

Digram 12: Orthographic drawing of the 3rd bridge

3rd Bridge Design

Length : 70cmHeight : 10cmWidth : 8cmMass : 0.125kgMax. load : 2.79kgEfficiency : 62

Figure 25: Model testing of 3rd bridge.

Figure 26: Joint detail of 3rd bridge.

Figure 27: 3rd bridge’s failure.

5.5 Proposed Design - Part 3 4th & 5th BRIDGE DESIGN

Figure 28: 4th and 5th bridge in comparism

These two designs are merging the strength and advantages of previous designs, combining

the truss arrangement from design 3 and triangular shape from design 1 and 2. Further exploration on

the jointing methods and the proportions to width and height are carried out.

5th Bridge Design

4th Bridge Design

4th Bridge Design 5th Bridge Design

Cross section :

Jointing :method

Overlaid Joint Butt Joint

Figure 29: Excess material can be cut off after assembly

Figure 30: Require careful sizing

5.6 Truss Analysis - Part 3

Figure 31: Weak point in the 4th bridge joint

The 4th design failed at its joint before it buckled under a load of 4.4kg. It was believed that if that

particular joint was properly glued and bonded with other members, it

could withstand a much higher load before it collapses. However, the

5th design was a total failure. The horizontal member on the top broke

off from other parts while the rest of the bottom part was still in good

condition under the load. It was proved that the jointing method

between the diagonal truss and the top horizontal member is not

workable.Figure 32: Close up of weak point

4th Bridge Design

Figure 33: 4th and 5th bridges’ failure.

5th Bridge Design

4th Bridge Design 5th Bridge Design

Length : 70cm Length : 70cmMax. height : 7cm Max. height : 8cmMax. width : 8cm Max. width : 5cmMass : 0.11kg Mass : 0.095kgMax. load : 4.4kg Max. load : 3.5kg

5.7 Final Design

Figure 34: Perspective view of final bridge design

The final bridge design is a modification of the 4th design by adding number of panels from 5

to 7 as reducing panel length could contribute higher strength to the structure. Moreover, a panel

length of 10cm stays in the range of panel length to span length ratio equals to 1: 6-8. By

understanding that fettuccine has a weak compression strength, the truss members which in

compression are designed with added layer. The bottom members in T shape are cut with calculated

angle in order to be properly glued and bonded with the horizontal strip of both sides to counteract

the outward-pushing forces. Also, every surface at joints are worn flat to provide maximize area of

bonding. Further strengthening work is applied at the midpoint of the bridge as well as at the point

meeting the edges of supporting body at the both sides.

Diagram 13: No bending force in triangular elements Diagram 14: Presence of bending force in rectangular elemetns

Design Idea and Reasoning

All the members at both sides of the bridge are arranged in triangle as there is no bending

moment in triangular element. However, in a cubic or rectangular element, the truss strength depends

on the bending strength of each member, which is unfavourable for the fettuccine’s properties.

Furthermore, as the weight of the bridge is indirectly proportional to the efficiency, bracing members

needed to stabilize the cubic or rectangular structure could increase the weight, decreasing the

efficiency.

Final Bridge Design

Length : 70cm

Height : 7cm

Width : 8cm

Mass : 0.131kg

Diagram 15: Truss Analysis for final bridge design

Diagram 16: Orthographic drawing of final bridge

Figure 35: Joints at the middle of the bridge. Figure 36: View of joints from bottom.

Diagram 17: Detail 1 Diagram 18: Detail 2 Diagram 19: Detail 3

3-layered

2-layered

CompressionTension

LOAD

Detail 1 Detail 2

Detail 3

6.0 Model Testing

A raffia string was used to tie at the top of the horizontal interconnecting member in the

centre between the two planar trusses of the bridge and a 'S' hook was hung onto the raffia string.

Starting at 2kg, we continued to put 500g load into the load carrier with 10 seconds intervals until we

reached 8kg. At this point, there is no more 500g load to be use, so we exchanged our 500g weights

that was already in the bag with two 2kg disc for 8 pieces of 500g load. We used the 500g loads until

the our bridge reached its breaking point.

Figure 37: A raffia string used to tie at the top of the bridge

6.1 Observation

As the experiment goes on, and the load gets heavier. There is a slight creaking sound and

also, the top part of the fettuccini started to bend. This may be due to the compression acting at the

top. The fettuccini bridge reached its breaking point at 12kg.

Figure 38: The top fettuccini bending upward

7.0 Analysis

7.1 Structural Analysis

A typical warren truss was selected as our fettuccine bridge design. The tension and

compression of the final bridge design were identified and calculated. As the strength of material,

type of adhesive, joining method, and orientation of fettuccine is tested in the beginning of the

assignment, we came to a conclusion that fettuccine is strong in tension and weak in compression.

Therefore, the member with compression force were build with thicker fettuccine (total 3 fettuccine

layer) while the member with tension force were joined with thinner fettuccine (total 2 fettuccine

layer). The reason is to maintain the strength of the truss in the compression part so that it will able

to hold the load for longer period.

We studied and analysed our bridge by doing some calculations and this is what we obtained.

Diagram 20: Labels of each member

Diagram 21: Bridge with complete calculations

The top and bottom horizontal part of the fettuccine act as main structure of the bridge.

Therefore, it need to be the strongest part of the whole structure. We built the structure with total 4

fettuccine with alternative joining to avoid failure in certain edges.

Diagram 22 : Compression (red) and tension (blue) acting on the bridge when load is applied.

The force from the load tends to move to the end of the bridge and to the table. The bracing

in the middle part of the bridge were designed to hold tension force so that the bridge can support the

maximum load. The bracing of the bridge helps to transfer load to both end. Therefore, there is a

difference in force in both side of the triangle bracing.

In this fettuccine bridge, we tried to make a equilateral triangle in the facade part as well as the

sectional part. In the final fettuccine bridge model, our bridge reach the similarity of 92% of the

equilateral triangle which the angle is 54.46⁰ in both side and 71.08⁰ in another side. These enable

the bridge to reach the higher efficiency of transferring load.

7.2 Failure Analysis

In the final model testing, result is stated as below:

Weight of the bridge: 131g

Maximum load: 12kg

Efficiency: 1099

After obtaining the result, an investigation of the failure of the bridge is carried out. We

found out the reasons for failure with several factors that could be improved.

Reason 1: Uneven load distribution in each members

We understand that fettuccine is good in tension and weak in compression. In our bridge

design analysis, we found that one side of the bridge is in compression, therefore, we decided to

enhance the members under compression by adding the fettuccine up to 3 layers, where the members

in tension is only 2 layers.

Diagram 23: Members in tension used 2 layers, while members in compression used 3 layers.

The strategy of additional layer on members under compression was not a good idea.

Although adding more layers would strengthen the compression members, it is very limited as

fettuccini has weak ability to withstand compression force.

Reason 2: Condition of external span on two side of table

Diagram 24: Members that rests on the table plays an important role in supporting the whole bridge

We also realize that the member that rests on the table (external span) plays an important role

as a base for supporting the whole bridge. In the final bridge design, only 10cm of the bridge were

placed on the table, therefore, when load were added on the bridge, strength of the lower horizontal

member results in shear force. The external span of the bridge is not stable enough to perform well in

supporting more load as it was not designed to address this issue.

Reason 3: Height of Fettuccine using ratio of Sydney Harbour Bridge in smaller scale

In order to achieve better dimension of the bridge, we calculated the height and width of the

bridge in ratio with Sydney Harbour Bridge. This results in the height of Fettuccine Bridge being

3-layered

2-layered

3-layered

2-layered

CompressionTension

7cm. After the final model testing, we found out that although the triangle shape is a very rigid

structure and it is able to transfer the load from one point to another. The lower height of our bridge

does not have a higher opposite force against the load carried. The bridge would be able to withstand

a higher load if the height was higher.

7.3 Design Modification

After several model making processes, it is evident that the critical thinking and observation

has helped us improve in the final outcome of our model with a 131g fettuccini bridge being able to

carry a load up to 12kg, which has the highest efficiency compared to our earlier designs. The

strategy is to use minimal material in order to maximize efficiency. However, after the final model

testing, we discover that the broken point of the bridge started from base member which 10cm away

from the centre point, thus, it is obvious that this bridge design has achieved its maximum load

carried as the breaking part are in tension and fettuccini are good in tension.

Figure 39: Broken member of the bridge after testing.

Diagram 25: Lower bridge (left) withstands a lower load as compared to the higher bridge (right)

Load Load

During the final model testing, the placement of external span of bridge was not placed at

the centre perfectly as the broken point of bridge is slightly at the side. In the process of loading

the weights into the load carrier, the moving hook caused the bridge to move a few centimetre

more to another side of table, causing the distribution of the load to be uneven to supporting

members. Therefore, a fixed point should be used on both sides to prevent to bridge from

moving.

Diagram 26: Green boxes representing a fixed point.

Moreover, there were 3 layers of fettuccine which were used for base members and heading

members where it was join vertically because it has better strength in tension. Adding another layer

would not be a better solution to carry a higher load as the weight of bridge will increase and the

efficiency will decrease respectively.

On the other hand, we must take into account that the bridge is exposed to different

temperature, affecting the strength of the fettuccine. Although, we have tried to avoid the difference

in outdoor and indoor temperature, in some circumstances, a minor crack is still seen after changing

the surrounding temperature from studio (cold and moist) to outdoor (hot and humid). Therefore, the

temperature of the working place for model making should avoid low temperature (16’C – 26’C).

Fettuccini is a biodegradable material. Therefore, the opened fettuccini must be kept in a air

tight box to avoid air exposure. The fettuccini cannot be exposed to direct sunlight as it will damage

the material. Moreover, we cannot construct the bridge too early as it will weaken with time. We

cannot construct the bridge too late as the glue needs time to dry. The time estimated to construct the

bridge plays an important role in determining the strength of the bridge.

8.0 Conclusion

The fettuccine bridge was considered as a successful bridge as it can withstand 12kg of loads,

with one of the highest efficiencies which is 1099.

In order to have a better understanding of the load distribution of trusses, we have done a structural

analysis of the fettuccine bridge to identify the forces acting upon each member, so as to determine

the critical member that needs to be strengthened.

By constructing a truss bridge using fettuccine, we need to make sure the materials given are

to be used at its full potential. Not to mention that good workmanship is essential to achieve quality,

it is also very important to have a feasible and well-thought construction sequence throughout the

process.

As future architects, it is significant for us to take all these factors into consideration when it

comes to a real design.

9.0 Appendix

A total of 6 trusses are designed for further analysis as an individual task in this assignment. The following are the task distribution for the cases:

Case 1: Wong Jia Xin 1101G1277Case 2: Feiven Chee 0312004Case 3: Tang Hui Ying 0312089Case 4: Celine Tan Jean Inn 0303669Case 5: Astari Razak 1101P11983Case 6: Hong Si Mun 0312643

10.0 References

Australian Government 2008, Sydney Harbour Bridge, viewed 6 April 2014, http://australia.gov.au/about-australia/australian-story/sydney-harbour-bridge

Garrett's Bridges 2011, Pratt Truss, viewed 12 April 2014, http://www.garrettsbridges.com/design/pratt-truss/

RTA timber truss bridge strategy n.d , Allan truss bridge, viewed 13 April 2014, http://www.rms.nsw.gov.au/roadprojects/projects/maintenance/documents/timber_truss_bridges/appendix_1c_bridge_profiles_allan_trusses.pdf

Prof. Markov, I n.d., Truss Simulator, http://ivanmarkov.com/truss-simulator.html