1. The document describes a student project to design a fettuccine truss bridge with a 750mm clear span and maximum weight of 200g.
2. Precedent bridge studies and material tests were conducted to inform the design process. Several bridge designs were developed and tested, with refinements made to designs that did not meet requirements.
3. A final design was a warren truss bridge with a 980mm length, 216g weight, and efficiency of 0.1531. Failure analysis found issues with workmanship, redundant members, and insufficient adhesive bonding contributed to its lower efficiency than expected.
Organic Name Reactions for the students and aspirants of Chemistry12th.pptx
Building structure (project 1:Fettuccine Truss Bridge)
1. Schoolof Architecture, Building & Design
Research Unit for Modern Architecture Studiesin SoutheastAsia
Bachelor of Science (Honours) (Architecture)
Building Structures[ARC2523]
Project1: Fettuccine Truss Bridge
Tutor: Mr. Mohd. Adib Ramli
Groupmember:
Tan Wei How 0310707
Teh Xue Kai 0317021
How Pei Ngoh 0316929
Ang Jia Pin 0315506
Lucas WongKok Hoe 0309421
WongKah Voon 0317510
2. Content
1. Introduction
1.1 Objective of project
1.2 Project requirement
1.3 Project schedule
2. Precedent studies
2.1 Navajo 1995 Bridge
2.2 Pratt Truss Bridge
3. Equipment and material study
3.1 Types of fettuccine
3.2 Adhesive test
3.3 Layering test
3.4 Clear span test
3.5 Joint test
4. Design process
4.1 Design 1
4.2 Design 2
4.2.1 Initial design
4.2.2 Modified design
4.2.3 Final design
5. Structural analysis of final design
5.1 Comparison between final design and modified design
5.2 Internal forces
5.3 Reflection
6. Reference
7. Appendix
7.1 Structural analysis of Final Design
7.2 Case Study 1
7.3 Case Study 2
7.4 Case study 3
7.5 Case study 4
7.6 Case study 5
7.7 Case study 6
3. 1.0 Introduction
1.1 Objective of Project:
To design a fettuccine trussbridge usingunderstandingon tension, compression andforce
distribution ina truss.
1.2 Project Requirements:
Design andconstructa fettuccine bridge with 750mm clearspan, maximumweight of 200g and
high efficiency.
bridgeofWeight
LoadMaximum
,
2
EEfficiency
1.3 Project Schedule
Date Task
23/03/2015 Precedentstudiesontrussbridge
26/03/2015 Discussiononprecedentstudies
31/04/2015 Preparingmaterials
04/04/2015 Equipmentandmaterial study,eg.adhesive test
08/04/2015 Buildingof Prototype Bridge 1
10/04/2015 Testingof Prototype Bridge 1
15/04/2015 Buildingof Prototype Bridge 2
17/04/2015 Testingof Prototype Bridge 2
20/04/2015 Buildingof Prototype Bridge 3and4
24/04/2015 Testingof Prototype Bridge 3and 4
25/04/2015 Buildingof PartsforFinal Bridge Design
26/04/2015 Assemblingof Final Bridge Model
27/04/2015 Final testingof Final Bridge Model
4. 2.0 PrecedentStudies
2.1 Navajo 1995 Bridge
Figure1 showsNavajo 1995 Bridgeperspectiveview.
Navajo Bridge crosses the Colorado River's Marble Canyon near Lee's Ferry in the
US state of Arizona. It carries U.S. Route 89A. Spanning Marble Canyon, the bridge
carries northbound travellers to southern Utah and to the Arizona Strip, the otherwise
inaccessible portion of Arizona north of the Colorado River.
The Navajo 1995 bridge is 143 meters height above the Colorado River. It has 11 spandrel
panels within the main span, which is 221 meters span. Each panel is 10 meter from each
other. (Godaddy software, 2010)
8. 2.2 Little Walnut River Pratt Truss Bridge
Figure 12 showsLittle River Pratt TrussBridge elevation.
The Little Walnut River Pratt Truss Bridge is a Pratt truss bridge. It was constructed
shortly after 1885, in Bois d'Arc, Kansas. The bridge was constructed by the Kansas City
Bridge and Iron Company as a carriage, horse and pedestrian bridge over the Little
Hickory Creek. The bridge connects the Walnut River in southern Butler County. It was
added to the National Register of Historic Places in the year 2003.
The height limitation of the bridge is 6 feet and 6 inches. Consisting of two distinct
spans, one span of 102 feet and the other 75 feet in length, using the Pratt Truss bridge
design. The bridge is iron manufactured by the Carnegie Steel Company. The road surface
is made of heavy timber. The total length of the bridge is 196.8 feet and the width of the
deck is 13.4 feet.
9. Figure13 illustrateselevation of Little WalnutRiver PrattTrussBridge, 1885.
Figure14 illustrates reaction force.
LOAD
Tension
Compression
11. 3.0 Equipmentand MaterialStudy
Figure19 showsaveragethicknessofa singlefettuccineis 10 mm.
Figure20 showsfettuccine comesin different length with an averageof 250 mm.
3.1 Types of Fettuccine
Constant Length = 60mm, clear span = 40mm, no. of layers = 2,
adhesive
Manipulated Brand
Responding Ability to withstand load for 10 seconds.
Brand Load withstand/g Cross-section of fettuccine
Kimball 200
San Remo 165
Barilla 105
Average length: 250mm
Average thickness: 10mm
12. Conclusion: Barilla fettuccine is the strongest, but San Remo is the most
suitable for bridge making as it has flatter surface which enables larger contact
adhesive surface.
Figure 21 illustrates how surface condition influences strength of fettuccine.
3.2 Adhesive Test
Figure 22 shows how test is being carried out.
Constant Length = 60mm, clear span= 40mm, no. of layers = 2
Manipulated Adhesive
Responding Ability to withstandthe load for 10 seconds
*Remark:V=vertical, H=horizontal, load [=water+150g (container+hook + thread)]
Adhesive
Water /g
300 800 1300
V H V H V H
3-seconds √ √ √ √ √ √
Bossils √ √ √ √ √ x
Dunlop √ √ √ x x x
PVC √ √ √ x x x
Super glue √ √ √ √ √ x
UHU √ √ √ x √ x
White glue √ √ √ x x x
3s+Dunlop √ √ √ √ √ x
3s+PVC √ √ √ √ √ x
3s+UHU √ √ √ √ √ x
Bossils+Dunlop √ √ √ √ √ x
13. Bossils+PVC √ √ √ √ x x
Bossils+UHU √ √ √ √ √ x
Conclusion: 3-secondsglueis the mosteffective glue. White glue is water-basedglue soit
actually softensfettuccine by a certain degree andmakesits joints weak.
Constant Length = 255mm, clear span= 110mm, no. oflayers= 4, water = 500g
Manipulated Adhesive
*Remark:V= vertical, H= horizontal
Adhesive V H
3s √ √
3s+Dunlop √ x
3s+UHU x x
Conclusion: 3-secondsglueperforms well even in longer clear span.
3.3 Layering Test
Constant Adhesive= 3-seconds, load(water= 500g), length= 255mm
Manipulated No. of layers
*Remark:V=vertical, H=horizontal
No. of layers
Clear span /mm
110 130 150 170 190 210 230
V H V H V H V H V H V H V H
2 x x x x x x x x x x x x x x
3 √ √ √ √ √ x x x x x x x x x
4 √ √ √ √ x x √ √ √ √ √ x x x
5 √ √ √ √ x x √ √ √ √ √ √ √ √
Conclusion: Numberof layers needed increases as clear spanincreases.
3.4 Clear Span Test
Constant Adhesive= 3-seconds, load(water= 500g), length=255mm, no. oflayers= 4
Manipulated Clear span
*Remark:V=vertical, H=horizontal
Clear Span /mm V H
70 √ √
90 √ √
110 √ √
130 √ √
150 √ √
170 √ √
190 √ √
210 √ x
230 x x
14. 3.5 Joint test
Figure 23 shows three different typesof joint. They are commonly used
in timberconstruction and fettuccine comesin shapesimilar to timber. No
fixture is required for thesejoint thusdamageto fettuccineisavoided.
Figure 24 shows how test is being carried out using frame, strap with
chain and plastic bag filled with water. Water is weighed using electric
balance.
Constant Dimension offrame =50 x50 mm, no. oflayers =3, adhesive=3-seconds
Manipulated load [= water +80g(plastic bag + strap)]
Responding Ability to withstandthe load for 10 seconds
*Remark:fettuccineframe is tested vertically, load [= water+80g (plasticbag + strap)]
Joint
Load /g
500 1100 1500 2000 2400
Butt
√ X (2.60s) X X X
Lap
√ √ √ √ X (1.00s)
Mortiseand tenon
√ √ √ X (3.93s) X
Conclusion: Lap joint has less contact adhesive surface than mortise and tenon but it is the
strongest.
Butt Joint Lap Joint Mortise andTenon
15. 4.0 Design Process
4.1 Design 1
Figure 25 shows the reaction force diagram of the bridge. Inspiration of this design is taken from
Navajo TrussBridge.
Force
750100 100
60
Front View
Top View
Tension
Compression
100 750 100
40
140
Figure 26, 27 & 28
show testing of
Design 1.
16. Total Length = 950mm Clear Span = 700m
Weight of Bridge = 260g Load Sustained = 1600g
Efficiency = 0.0098
Design 1 is inspired by the Navajo 1995 Bridge (Precedent Study), which is the deck arch
truss. This design has high aesthetic value but it exceed the 200 grams to 260 grams.
Problem Identification:
1. The bridge is over-weight, 260 grams.
2. The bridge experienced twisting when load applied.
3. The end of the bridge was not strong enough and it broke.
4. The forces are not fully distributed to some of the members of the bridge as the
joints are not connected properly.
5. Efficiency of bridge is not satisfied yet for us although there is improvement.
4.2 Design 2
`
Figure 29 illustrates the reaction force of the bridge.
42
58
950
60
75
60
100
100
950
Forces
Tension
Compression
17. Figure30 showstesting of Design 2.
Total Length = 950mm Clear Span = 700m
Weight of Bridge = 200g Load Sustained = 6180g
Efficiency = 0.1910
Design 2 used back the same design as Design 1, which is the deck arch truss with some
improvement. Thus, its efficiency is getting higher compared to Design 1. However, its
aesthetic value is still remained the same
Improvement:
1. Decrease numbers of panel and layers of the tension members in order to
decrease the weight of the bridge. (The weakness of design 1)
2. Add bracing of the top. (The weakness of design 1)
3. Strengthen the both the ends of the bridges, adding more layers to make it
thinker. (The weakness of design 1)
4. Add three triangular members to the centre of the bridge to strengthen it.
5. Improve the way of connecting the joint by using mortise and tenon joint. (The
weakness of design 1)
Problem Identification:
1. The middle part of the bridge is still not strong enough to withstand the load.
2. Efficiency of bridge is not satisfied yet for us although there is improvement.
18. 4.3 Design 3 - SpaceTruss
Figure30 illustratesreaction force in SpaceTruss.
Total length = 800mm
Weight of bridge = 140g
Efficiency = 0.0926
Clear span= 750mm
Load sustained= 3.6kg
Efficiency = 3.62
/140 =0.0926
Figure31 showstesting of Design 3 – TrussBridge.
800
80
800
50
50
Tension
Compassion
19. Figure32 showsfailure of TrussBridge.
Problem identified:
1. The joint of the bridge is not strong enough to withstand the load.
2. Mortiseand Tenonjoint methodused is goodfor fixing the members together however
the strengthof the joint is low.
3. The members turnedbrittle and weak after 2 days
4. The height of the bridge is toohigh in relation to the width.
5. Unevenload distributiondueto the toppointof trussdid notmeet with anotherside and
form a pyramid.
20. 4.4 FinalDesign 1
Figure33 illustratesreaction force of thebridge.
ProblemIdentified:
The top chordwas not properly glued to the membersof the truss.
Improvement suggested:
1. The height of the bridge is decreased.
2. Buttjoint is used.
3. More layers are addedto trussmembers andchord.
Top View
Front View
Cross-section
60
60
55
55
980
55
980
55
Compression
Tension
Forces
21. Final Design 2
Figure 34 illustrates reaction force of the bridge.
ModelTesting
Two lanyards were used at two points of the top horizontal interconnecting member in thecenter
between thetwoplanar trussesofthebridge. Thenthelanyards weretiedtoa pail. Startingat530g
(the weight of the pail) we pouredin water tothe pail ourbridge re
Figure 35 shows
testing of Final
Model.
Top View
Front View
Cross-section
60
60
55
55
980
55
980
55
Compression
Tension
Forces
22. Modified Design 2 Final Design 2
Total
length
/mm
900 980
Clear
span
/mm
750 750
Total
weight
/g
160.0 216.0
Load
withstand
/kg
8.100 5.750
Efficiency
/kg2
g-1
8.12
/ 160 = 0.4101 5.752
/ 216 = 0.1531
Time
between
completio
n and
testing
/ hr
48 3
Cross-
section
Elevation
Adhesivemedium added ontopof
base chord toincreasecontact
adhesivesurface.
23. Failure Analysis
1. Time between completion and testing of final bridge is too short. Fettuccine truss
has lower load bearing when adhesive is still wet.
2. Base chord should be perpendicular to desk surface to ensure maximum surface
area is used for load transfer. Diagonal base chord is due to poor workmanship.
3. Weight of 20cm fettuccine is 1.30g. 17 pieces of 5cm doubled-layer hanging
member contribute to redundant members of approximately 11g.
4. Adhesive medium added to enable greater contact adhesive surface is not glued
tightly to base chord. This is the paramount reason for lower truss efficiency.
Structural Analysis
Our final fettuccine bridge model is designed based on a warren (with verticals) truss
design. The reaction forces of the bridge were calculated and identified. The bridge was
tested with multiple types of adhesive and joining methods. We obtained different levels
of strength in different types of design. The result of the testings showed that fettuccine
is strong against tension and weak against compression forces as fettuccine is higher in
elasticity. The strength is also determined by the amount of fettuccine used per part. The
top and bottom chords of the bridge were using more layers than the posts and the
braces. After testing the final model of the fettuccine bridge, we obtained calculations of
forces and reaction forces acting upon the bridge. (Garrett, B., 2011)
Aspect ratio or lower span to longer span ratio for truss frame is 1-1.5, 1.5-2.0 will affect
effective load transfer in space frame member. In final design, ratio of 1.1 (5.5/5) is
within the range. (Tian, T.Lan, 2005)
Figure 36 illustrates how Final Model is was bent during final testing.
24. Figure 37 showslabelling of Final Model in StructuralAnalysis(refercalculation in Appendix:Final
StructuralAnalysis).
Conclusion
After all it was a good experience to construct a truss bridge by using fettuccine because
it is a totally new material for us to explore. We carried out tests to study the material’s
tensile and compressive strength. By understanding the nature of the material, we can
utilize it to its full potential in making a stronger bridge. Not to mention the type of
adhesive, we also learn that workmanship plays an important role in increasing the
bridge’s strength and efficiency. This reflects in reality, the stability and strength of a
construction is massively affected by the adhesive too. Furthermore, we learned that the
procedures in a construction need to be well-planned and organized. It is very important
to have a well-thought construction sequence throughout the process.
As a conclusion, I think that our group did a good job although the final testing is a failure
compared to the previous one. We explored 4 prototypes by developing and improvising
them based on two main designs from precedent studies. Analysis was done on the load
distribution and at the same time, we successfully determined the critical members and
enforced them by adding layers and pushing the weight of the bridge to 200gram which is
the limit because our previous design weighed only 180gram. This is responding to the
efficiency formula which has square for the maximum load, so by increasing the weight in
order to strengthen it, the bridge can support heavier load, then the efficiency can be
increased by higher rate.
As a designer, it is not a big deal if once in a while our design does not work well or even
fail, it is just that we have to absorb the lessons and learn from it so that in upcoming
projects we can address it. This is because after all designing is a life-long process and we
should always enjoy it by living it to the fullest.
7.0 Reference
Godaddy software. (2010). Highestbridges. Retrieved 6 April, 2015, from
http://www.highestbridges.com/wiki/index.php?title=Navajo_1995_Bridge
Garrett, B. (2011). Garrett's Bridges. Retrieved 3 May, 2015, from
http://www.garrettsbridges.com/design/pratt-truss/
Tian, T.Lan. (2005). Space Frame Structure. Retrieved 3 May, 2015, from
http://www.gfsmaths.com/uploads/1/0/0/4/10044815/ch24spaceframestructure.pdf
8.0 Appendix (Attachment)