Bridge report final

BUILDING STRUCTURE (ARC2523) PROJECT 1: FETTUCCINE TRUSS BRIDGE ONG WEI HOOW GAN SZE HUI TAY REN SIONG BRANDON ANG EE SHEN TIE SING KIONG NICHOLAS TIONG ING JUN

0304468 0303709 0303286 0302955 0304054 1103p11824

Content 1. Introduction 2. Methodology 3. Precedent Studies 4. Materials & Equipment 5. Model Making & Design Development 6. Structural Analysis 7. Conclusion 8. Appendix 9. References

1 Introduction Truss is a structure built up of three or more members which are normally considered being pinned and hinged at the joints. The following figure shows different types of trusses. Load applied to the truss is transmitted to joint so that each individual members are in either pure tension or compression.

1.1

General Brief of Truss

Truss is a structure built up of three or more members whose ends are being pinned and hinged at the joints referred to as nodes. Load applied to the truss is transmitted to joint so that each member is in either pure tension or compression.

1.2

Aim of Study

a)

To develop student’s understanding on the construction materials in term of tension and compressive strength.

To develop student’s understanding on a truss in term of force distribution.

To design a perfect truss bridge that consists of high level of aesthetic value and minimal construction material.

b) c)

1.3

Learning Outcomes

The learning outcome of this project is to evaluate, explore and improve attributes of construction materials (fettuccine). In addition, we can explore and apply understanding of load distribution in a truss bridge. Not only that, we can explore different arrangement of members and apply the understanding of load distribution in a truss structure within the project.

2 Methodology 2.1

Precedent Study

We have to research for a truss bridge and study on its connections, arrangement of members and orientation of each member. The fettuccine bridge will be designed and constructed based on the information of the precedent study.

2.2

Materials Testing & Equipment Preparation

Exploration on the materials used in term of its strength by different types of testing. Equipment is prepared before the testing of truss bridge.

2.3

Model Making & Design Development

The Fettuccine Bridge is designed in AutoCAD software and is printed out to scale for model making.

Requirements of Fettuccine Bridge: a) 600mm clear span bridge. b) Maximum weight of 150g. c) Only fettuccine and glue can be used. d) The bridge will be tested to fail.

The strength of the model will be maintained and the weakness will be eliminated for further development.

2.4 Structural Analysis Structural Analysis is the determination of the effects of load on the Fettuccine Bridge and its members by calculation.

2.5

Bridge’s Efficiency Calculation

Efficiency of the bridge is calculated after it is tested to fail by using formula: Efficiency, E = (Maximum Load) 2 Mass of Bridge

3 Precedent Study Klang Kota Bridge

Kota Bridge, Klang or Jambatan Kota, Klang is the first double-decked bridge in Malaysia. It is located in Klang, Selangor. It was built in May 1957 by British Dorman Long Bridge and Engineering Ltd Company. The bridge’s main span over the Klang River is 500 meter. It was a reinforced steel truss girder bridge.

The bottom deck is a pedestrian walkway bridge while the top deck is a motor vehicle bridge. However, in the year 1990s, the top deck of bridge was renovated into bridge square called Dataran Jambatan Kota.

It is a double decker truss girder bridge that uses Warren truss with verticals as members to distribute load above.

LOAD

REACTION FORCE Compression Tension

Diagram 3.1 shows the compression & tension forces acting on Warren Truss.

Truss Members & Connection Parts

Diagram 3.2 shows the detailed connection parts of the bridge.

Exterior View

Interior View

Rigid Connection with Gusset Plate

4 Materials & Equipment 4.1 Fettuccine (Main material) Two types of Fettuccine are used for testing to determine their strength and suitability for model making.

Red Packet

Green Packet Strength Testing (200mm clear span)

Number of Fettuccine used

Weight sustained/ ml (Green Packet)

Weight sustained ml (Red Packet)

1

200

210

2

300

330

3

405

460

4

520

600

*100 ml = 100 grams Table 4.1.1 above shows the analysis of fettuccini strength by applying point load (water) on middle point of the fettuccine.

Suitability

Curve Surface

Flat Surface

Fettuccine from Red Packet is more suitable and easy to stick together as the surface is more flat compared to Green Packet.

4.2 Glue (Adhesive Material) Exploration on several types of glue to determine which one is the most suitable as the adhesive material in term of efficiency for the model making.

Types of Glue

Observation & Description

3-seconds Glue

1) High efficiency 2) Fastest solidify time 3) Lighter in weight

Elephant Glue

1) High efficiency 2) Longer solidify time 3) Lighter in weight

2

Hot Glue

1) Low efficiency 2) Longer solidify time 3) Heavier in weight

3

UHU Glue

1) Low efficiency 2) Longest solidify time 3) Heavier in weight

4

Table 4.2.1 above shows the efficiency of different types of glue.

Efficiency Ranking 1

4.3 S-Hook & Raffia String The S-Hook is used to hang the load with the aid of Raffia String on the Fettuccine Bridge. Hence, all the forces are applied on one point of the bridge.

4.4 Weight & Water Bottles Weight and water bottles act as the load to test the strength of Fettuccine Bridge. Remark that 100ml is equal to 100 grams.

4.5 Weighing Machine It can be used to weigh the mass of the Fettuccine Bridge to ensure that we did not exceed maximum weight of 150 grams.

4.6 DSLR Camera DSLR Camera is used to record the making process and result of the Fettuccine Bridge as the evidences.

5 Model Making & Design Development Requirements of Fettuccine Bridge: a) 600mm clear span bridge. c) Only fettuccine and glue can be used.

Fettuccine Bridge Design 1

b) Maximum weight of 150g. d) Bridge will be tested to fail. * Assumption Made Compression Tension

Load

Reaction Force

Reaction Force

Joint that was broken

Total Length Weight of Bridge Efficiency

=600mm =260g =311.54

Clear Span Load Sustained

=400mm =9kg

Design 1 has high aesthetic value and efficiency but it exceeds the 150 grams and does not reach 600mm clear span as required.

Solution: 1) Extend the clear span of bridge up to 600mm to fulfil the requirement.

2) Decrease the layer for each member is the solution to lower the weight of bridge which does not exceed 150 grams.

Fettuccine Bridge Design 2

* Assumption Made Compression Tension

Reaction Force

Reaction Force

Load

Joint that was broken

Total Length Weight of Bridge Efficiency

=800mm =200g =125

Clear Span Load Sustained

=600mm =5kg

Design 2 has achieved 600mm clear span but still exceeds the 150 grams as required. However, it has high aesthetic value but has low efficiency.

Solution: 1) Decrease more layers for each member to achieve the maximum weight of 150 grams.

2) Due to less load can sustained and low efficiency of the bridge, the bracing system from Warren Truss (Precedent Study) will be applied to next design.

Fettuccine Bridge Design 3

* Assumption Made Compression Tension

Reaction Force

Reaction Force

Load

Triangle Bracing on the tip

Joint that was broken

Total Length Weight of Bridge Efficiency

=800mm =160g =156.25

Clear Span Load Sustained

=600mm =5kg

Design 3 applies bracing system from Warren Truss (Precedent Study). Thus, its efficiency is getting higher compared to Design 2. However, its aesthetic value is slightly lower compared to Design 2.

Problem Identification: 1) Weight of bridge still exceeds 150 grams.

2) Efficiency of bridge is not satisfied yet for us although there is improvement.

3) The joint on the tip and also on the centre of bridge are the weakest part.

Solution: 1) Remove the bottom part of the bridge to decrease the bridge mass.

2) Increase the number of layer for all critical members of the bridge.

3) Apply rectangular bracing instead of triangle on centre of bridge.

Fettuccine Bridge Design 4

* Assumption Made Compression Tension

Reaction Force

Reaction Force

Load

Rectangular Bracing

Lack of Bracing Horizontally

Total Length Weight of Bridge Efficiency

=665mm =144g =250

Clear Span Load Sustained

=600mm =6kg

The efficiency of design 4 has good improvement after the application of rectangular bracing on the centre and the decrease of bridge mass.

Problem Identification: 1) The bridge experiences twisting when load applied.

2) The forces are not fully distributed to some of the members (top part) of the bridge when the load pulling downwards.

Solution: 1) Apply bracing system horizontally to avoid twisting.

2) Change the load hanging point from bottom to top of bridge.

3) Turn the arrangement of members (bracing) oppositely due to the changing of load hanging point to the top.

Fettuccine Bridge Design 5

* Assumption Made Compression Tension

Load

Reaction Force

Reaction Force Load Hanging Point

Bracing is added horizontally.

Side part of the bridge was broken.

Total Length Weight of Bridge Efficiency

=665mm =140g =257.14

Clear Span Load Sustained

=600mm =6kg

Design 5 applied bracing horizontally to avoid twisting of bridge. Load is hanging on the top and transfers all the forces from top to bottom fully. The efficiency has improved as well.

Problem Identification: 1) When comes to 6kg, one of the sides of the bridge broke instead of the centre part.

Solution: 1) Add the vertical members on the both side of the bridge to ensure that the force can be transfer to the table (ground).

Fettuccine Bridge Design 6 (Final Design)

* Assumption Made Compression Tension

Load

Reaction Force

Reaction Force Vertical members are added.

Total Length Weight of Bridge Efficiency

=665mm =143g =1006.99 / 1007

Clear Span Load Sustained

=600mm =12kg

Summary Apparently, the efficiency of final design (Design 6) is boost up from 257.14 to 1007. Good workmanship and good design for load transfer are the main reasons to achieve that level of efficiency for Fettuccine Bridge. In addition, the final model is done just one hour before the final testing to reduce the chemical side effect of 3-seconds glue on the Fettuccine Bridge. The longer the time after Fettuccine Bridge has being done, the more the chemical side effect of 3-seconds glue will react on the bridge, the lower the efficiency will be.

6 Structural Analysis

Diagram 6.1 shows the structural analysis in term of tension, compression & zero force. With the aid of diagram, we can identify the critical members of the bridge and strengthen them by adding layers of Fettuccine.

6.1 Calculation

6.2 Strengthen of Members 4 layers member (top & bottom part as critical members)

Side View

3 layers member (vertical support)

Side View

2 layers member (bracing & horizontal support)

Side View

Top View

7 Conclusion As a result, it is a very satisfactory outcome we made for our Fettuccine Bridge with the efficiency = 1007. This efficiency is quite high among the class.

To achieve that, we explore further on the properties of Fettuccine in the process of bridge making. To achieve a better bridge efficiency, we also keep trying and exploring different types of Fettuccine Bridge. With that, we can identify the critical members in the bridge and strength them. In addition, we also use Newton’s law as reference to design the bridge as well. Moreover, good workmanship and good team work are also the keys to success in this project. In conclusion, this project teaches us the proper way to construct a truss structure.

8 Appendix Final Bridge Photos

Group Photos

ONG WEI HOOW 0304468 (CASE 1)

TIE SING KIONG 0304054 (CASE 2)

GAN SZE HUI 0303709 (CASE 3)

TAY REN SIONG 0303286 (CASE 4)

BRANDON ANG 0302955 (CASE 5)

NICHOLAS TIONG 1103p11824 (CASE 6)

Case Study Analysis

Number of 0 Force Member Highest Critical Force

Case 1 & 2

Case 3

Case 4 & 5

Case 6

2

1

0

1

252.1kN 228kN 252kN 228.05kN

Conclusion Truss system in case 4 & 5 is the most effective because it has no zero force member in it. Hence, all the forces are transferred fully to the whole system, every members are transferring the load.

9 References B. Onouye. 2005. Statics and Strength of Materials: First Edition. Upper Saddle River, New Jersey: Prentice Hall, Inc. BS 8110: Part 1: 1985. British Standard: Structural Use Of Concrete. Part 1.

Code Of Practice For Design And Construction. British Standards Institution (BSI) C. K. Wang.1993. Intermediate Structural Analysis. New York: Mcgraw Hill Book Company.

D.F Mccarthy. 2002. Essentials Of Soil Mechanics & Foundations: Basic Geotechnics, 6th Edition. New Jersey: Prentice-Hall, Inc. R. C. Coates, M. G. Coutie, F. K. Kong. 1997. Structural Analysis: Third Edition. London: Chapman & Hall R. Whitlow. 2001. Basic Soil Mechanics 4th Edition. UK: Prentice Hall.