Building Structure (BLD61003)
Project 1:
Fe;uccine Truss Bridge Ting Peng Hang
0313515
Benard Chin
0313355
Wee Boon Bing 0313569 Liew Chung Hooi 0314126 Kelvin Cheong 0310354 Eric Lai Yiew How 0313843
Table of Content
IntroducPon Methodology Precedent Study Analysis TesPng Conclusion Appendix References
INTRODUCTION General purpose of the project This project aims at evaluaPng, exploring and improving a;ributes of construcPon through designing an efficient truss bridge. This is done through the exploraPon of different truss systems and construcPon material [fe;uccine], adhesives, types of joints. By applying our understanding of tensile and compressive strengths of the bridge constructed throughout the project, we are able to calculate load distribuPon in a truss system. High level of aesthePc value and minimal construcPon material are the criteria to design a perfect truss bridge.
Project Outline In a group of 6 person, we have to construct a bridge using fe;uccine and adhesive materials [glue]. The bridge has limitaPon of maximum 80g and 350mm clear span. It is the tested using a point load. The hypothesis is the higher the amount of load carried, the more efficient the bridge. And also, the lighter weight of bridge, the higher its efficiency. These are what we aim to achieve for maximum efficiency. This report consists of a precedent study – Deep River Camelback Truss Bridge. In this case study, we look the bridge’s connecPons and joints, arrangement of each member and how forces are transferred throughout the truss bridge. Sets of tesPng results and development of our designated bridge through several trial-and-error experiments and failure analyses are included. Furthermore, calculaPon on the given quesPon and the truss of bridge itself. •
Bridge requirements:
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350mm clear span and maximum weight of 80g.
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Fe;uccine and glue are allowed.
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Point load; focus on specific point of the bridge.
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Must be able to withstand each weight that is put on for 5 seconds.
Methodology There’s several ways that we’ve carried out in order to achieve our objecPves: Phase 1 : Precedent Study By understanding what kind of bridge there are around the world, the approaches allow us to get ideas of how we should create and modify our bridges according to the precedent studies we have done. Next, we’re to refine our design ideas through several precedent studies that we have researched and analyzed how to apply it into our final design to get be;er results in the end.
Phase 2 : Materials & Adhesive Strength Test Firstly before construcPng our bridges, we’re to look into what kind of materials we should be using for the best results. Moreover, we did researched on what sort of fe;uccine materials we should use best for our design in order to achieve be;er results in the end. For Fe;uccine Bridge, we are to consider and test out what kind of materials/ how thick our materials goanna be & what kind of bridge design we should do in order to not exceed our total weight for the final bridge. Lastly we’re also looking into how the behavior of each materials reacts to the tension and compression in the bridge.
Phase 3 : Model Making For the design of Fe;uccine Bridge, we did several design to test out what’s the best for our final bridge. Hence we did generate a few designs through sketches and also from autoCAD. In the progress of making each model, we also taking consideraPon what way should the trusses be in order to allow the compression and tension to react to each other.
Phase 4 : Tes:ng & Analysis Aier all the designs & approaches we had, we did mock-up models for tesPng. With all the evidence & try-outs for our model, we had 6 tesPng bridges and slowly went down into one final design conclusion. All the trials and errors we had is to understand how the trusses and compression is transferred. Lastly, the final bridge is constructed aier we did all the try-outs and also we did some calculaPon and observaPon of our errors.
Working Timeline:
( Week 1 ) 29th August 2015 : -
Gekng materials ;
1. Several types of Fe;uccine 2. Several types of Super glue / Elephant glue ( Week 2 ) 5th September 2015 -
Building bridge 1 & TesPng out
( Week 3 ) 12th September 2015 -
Building bridge 2 & 3
( Week 4 ) 19th September 2015 -
Building bridge 4
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TesPng bridge 2 & 3 ( wait for glue to dry )
( Week 5 ) 27th September 2015 -
TesPng bridge 4
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Building bridge 5
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TesPng bridge 5 ( test for ďŹ nal )
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Final building bridge 6 ( aier all conclusion is made )
( Week 6 ) 28th September 2015 -
Bridge test at Campus E5
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Prepare for report compilaPon for all results taken.
Materials There’s several types of fe;uccine we’ve used.
Organic Brown Rice Pasta -Slightly Greenish Yellow -Quite soi -Slightly shorter than other fe;uccines
San Remo FeEuccine -Gold Yellow -Slightly soier / easily break -Flat & long shape
San Remo Spinach FeEuccine -Dark Greenish Yellow -Harder compared to other fe;uccine -Flat and long
Dumbbell -For weight tesPng on S-shape hook -0.5kg to 2kg dumbbells -Put on middle point load of the bridge
S Shape Hook -Be placed in the center of bridge for tesPng -Used together with dumbbell -For model tesPng
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- Kitchen Weight Machine •
- Used for weighPng bridge
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- Measuring equipment for bridge
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- Recording the weights of bridge
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Super Glue (Elephant) - Joining material for bridges - The strength is tougher than other glues / 3 second glue
Water Bucket - For tesPng bridge strength purposes - Dumbbell / Water bo;le to be placed for tesPng 

Water BoEle ( 500 ml ) -For tesPng the bridge strength -Each bo;le considered as 0.5g

Analysis Strength of Materials 1) Experiments with Fe;uccine Experiments were conducted to determine the strength of the fe;uccine by using different kind of laminaPon as well as different kind bonding. Different kind of bonding and laminaPon were tested at a minimum load of 500g. The table below show the Pme of different kind of layers of fe;uccine laminated to break. LaminaPng
Time
LaminaPng of beam
Time
1 layers
1 second
I- Beams 1 layers
4 seconds
2 layers
1 second
I- Beams 2 layers
6 seconds
3 layers
4 seconds
I- Beams 3 layers
Did not break
4 layers
More than 40 seconds
I- Beams 4 layers
Did not break
We tried 3 types of bonding methods, which are using, UHU glue, super glue and cello tape.
1) UHU glue – doesn’t really sPck both of fe;uccine, very weak bond, as it sPll lei gap at some point of the fe;uccine 2) Super glue – very sPcky, and doesn’t leave any gap 3) Cello tape – very strong bonding, but heavy and when it come to the joint, it cannot join properly
As a conclusion, I-Beam that with 3 layers and 4 layers laminaPng doesn’t break during the tesPng, but it become very heavy compare to the 4 layers normal laminaPng fe;uccine, so we have chosen 4 layers normal laminaPng method because it almost achieve the same result, yet very light weight. For the bonding methods, we used super glue as our methods, and it can sPck two fe;uccine firmly as well as when it come to the joint.
Mock-up Trusses Before we decide which kind of truss to apply in our bridge, we tested out a few Mock-Up bridge, and we tested unPl it break, and from there we try to idenPfy the reason for the bridge to break.
Warren Truss Break at 1kg 65g
Howe Truss Break at 5.5Kg 93g
PraE Truss Break at 6kg 71g
Aier we tried out 3 kind of trusses, we decided to use Pra; Truss as it can withstand more loads (6KG) than the other two reasonable weight at 71g. We also compared Pra; Truss and Howe Truss and we found out that, Howe Truss need a lot of reinforcement in member to withstand more loads, comparing to Pra; Truss, and then we assume that most of the Howe Truss member are in compression.
PraE Truss Mockup model The first mode we make was constructed by overlapping pieces of fe;uccine overlapping others member, and then we realized this joint is not good enough, it make the façade very fragile. This cause the force distribuPon unevenly and difficult. Aier the test we find out that some of the member doesn’t really transfer the loads as they only there to prevent the buckle and some of it is not strong enough and break. First we noPce that the beam in the middle that use to hold the load are not strong enough at the first place, it break when we tried to put more load while other member remain the same.
Aier the second test, we found that, on the top member and the base is break, so we reinforce the top member and the bo;om member to 4 layers, and the rest we remain, 2 layers, so the weight of the bridge wouldn’t excced the recquirement of 80g. And also to ensure the force can be distributed evenly, we change our joining method to bu; joint.
Final Model
So we idenPfy a few criPcal member based on the mockup model so, for the ďŹ nal model, we reinforce the member that break during the mockup from 3 layers to 4 layers, to help withstand even heavier loads, and we change our joining method to bu; joint to the force to distribute evenly.
Failure Analysis
We observed that the bridge failed at the center point, which is the beam that we hang the loads, and other member remain the same. The reason is because the middle beam is not strong enough to hold up the loads when it`s at 11 kg, while the rest of the member sPll can distribute the loads effecPvely. Based on the mockup model, the member we reinforced are the top compression member, and the bo;om one which is the tension member, as well as the V-shape truss member in the middle of the bridge.
Efficiency
In conclusion, the higher loads a bridge can hold with minimal weight the higher the efficiency, and calculaPng efficiency allow us to understand whether is this bridge a good design? Do it achieve or do it withstand the loads effecPvely.
Truss Analysis For analyzing purposes, the diagram below indicated the, TENSION, COMPRESSION, and ZERO FORCES member.
Blue – Compression Red – Tension Green – Zero force Bridge details: Weight of bridge : 83g Clear Span : 35mm Overall width : 40mm To double confirm our analysis, we use an apps called “Truss me” to help us to idenPfy the characterisPc of each member.
CONCLUSION We managed to keep the bridge around 80g weight limit with load capacity of 11.6kg. We realizes that is the significant to idenPfy the truss form, joints and point load members would increase work producPvity with correct calculaPon to interpretaPon of load on respecPve member. Adhesive and workmanship is important to ensure the member are strong and do not crack half way. We have using the same structure with bad workmanship and the result obvious different. Via this project, we have learnt to manipulate fe;uccine to construcPng a bridge and study the structural analysis regarding our truss. We have gained professional knowledge of truss design and do the math to understand capability of bridge structure. We believe the knowledge would beneficial in our future architecture design.
REFERENCES Boon, G. (2015). Garre<'s Bridges » Pra< Truss. Garre<sbridges.com. Retrieved 2 October 2015, from h;p://www.garre;sbridges.com/design/pra;-truss/
Lamb, R., & Morrissey, M. (2000). Truss Bridges: Beam Bridges With Braces. HowStuffWorks. Retrieved 1 October 2015, from h;p://science.howstuffworks.com/engineering/civil/ bridge4.htm
Nardon, J. (1996). Bridge and structure es:ma:ng. New York: McGraw-Hill.