B. Structure project 1 report

FETTUCCINE TRUSS BRIDGE

Kimberly Wong

0315145

Lai Chi Mun

0319463

Lau Wei Ling

0315389

Lim Chin Yi

0315627

Lim Shu Ting

0320102

Architecture Semester 4 March 2016 Intake Building Structures ARC 2523

Content No.

Page

1.0

Introduction

3

1.1

Precedent Studies

5

2.0

Analysis of Material Strength

9

 Modular test  Truss test 3.0

Construction of Bridge

13

4.0

Bridge Testing

14

5.0

Structural Analysis of the bridge

18

6.0

Conclusion

24

7.0

References

25

8.0

Appendix

26

2

1.0 Introduction In a group of 5, we were assigned to construct a fettuccine truss bridge. To understand the tension and compressive strength of truss system, we were to construct a perfect truss bridge.

Research and preparations were done before construction of the truss bridge.

To conduct the testing and construction of fettucine truss bridge, materials and equipment were prepared: A) Construction Material Different types of materials are prepared and tested. The material with the best compressive strength and adhesive strength are chosen for the construction of fettuccine truss bridge. 

Different brands of Fettuccines

San Remo Fettuccine

Kimball Fettuccine



Prego Fettuccine

Different types of glues

UHU glue

Superglue

PVC Glue

Hot glue

3

B) Construction Equipment The following equipment is used to construct the fettuccine truss bridge.

Sand paper

Cutter and cutting mat

For the initial stage of construction, cutter is used to cut the fettucine. The edge of the fettucine members is sand by using sand paper to make it fit to the flat surface.

C) Weight Testing equipment

S hook

Bucket

Water as weight

The load test was carried out by hanging the s hook to the middle of the fettuccine truss bridge. The other end of S hook will hang a bucket. Water that are measured to a certain weight will be added into the bucket slowly.

Adhesive Technique By applying point to point technique, the adhesive strength is compromised. It can support only 475g of compression force.

By applying in a line, the adhesive strength is much better. It can withstand 1537g of compression force.

4

1.1 Precedent Study Introduction to Truss Bridge Truss bridge is the bridge that uses truss as main element and they form into triangular unit when connected. Truss bridge structure is used widely due to its rigidity and it can distribute loads from a single point to a much wider area (Truss Bridge - Types, History, Facts and Design, n.d.). The bridge members are usually stresses from tension and compression force. Truss bridges can be categorized into 2 group, the perfect truss and imperfect truss.

Perfect Frame Frames that can be analysed to get the internal member forces and external support reactions through the three conditions of static equilibrium (Shiva, 2015). The formula N=2j-3 can be used to determine a perfect structure where ‘N’ is the number of members and ‘j’ is the number of joints.

Flat Pratt Truss

Waddell A Truss

Warren Truss

Howe Truss Warren With Vertical Truss

5

Fredericktown Bridge

Fredericktown Bridge is built in 1840 to 1844 and closed in 1907 and it collapsed 20 years later. This bridge is an 1893 truss bridge built by the Penn Bridge company of nearby Beaver Falls, PA. It was rehabilitated in 2004 and the deck replaced.

6

Warren Truss

The bridge that is with an equilateral truss, all panel lengths and diagonals are of equal length creating a series of equilateral triangles. When the panel lengths are shorter than the equal length diagonals, it was sometimes called an isosceles or isometric truss.

Warren Truss with verticals

As the length increases so does the height of the truss, compression is acted towards the members and bracing is needed to minimize buckling and to provide support for the vertical direction. The verticals are position from the lower chord panel points up to the midpoint of the chord member directly above. The deck structure stringers will lengthen in order to help the heavier members or any addition of verticals from the top chord panel points dropping down, to be able to shorten panel lengths.

7

2.0 Analysis of Material Strength 1. Modular Test

A) Material test using different brands of fettuccine and glue.

Load Test Brand

Glue

San Remo

PVA

100g

200g

300g

400g

500g

600g

700g

800g

Superglue Hot glue UHU Prego

PVA Superglue Hot glue UHU

Kimball

PVA Superglue Hot glue UHU

The test was done by stacking 3 pieces of fettuccine together with different types of glues. This is repeated with different brands of fettuccine.

From the result of the test, San Remo brand of fettuccine is the strongest among the 3 types of fettuccine while superglue has the strongest bonding strength. The combination of San Remo fettuccine with superglue can withstand 600g of load.

8

B) Compression strength test

San Remo Prego Kimball

Force exerted 0.50N 0.27N 0.25N

Compression strength is tested for different brand of fettuccine. The test is done by exerting force on fettuccine placed vertically on a weight balance. From the test, San Remo Fettucine has the best compression strength.

The compression strength is further tested by doing test on different number of layers of fettuccine Force exerted 1 layer of Fettuccine

Force exerted 3 layers of I beam

0.45N

2 layers of Fettuccine

14.67N

4 layers of I beam 2.68N

3 layers of Fettuccine

18.93N

5 layers of I beam 11.11N

47.73N

The 5 layers of I beam has the best structural strength. Thus, it is used as the bottom layer of the truss structure where it will carry the total weight of the structures.

9

2. Truss Test A) Trusses with different vertical members

Load Test

3000g

2750g

2500g

2250g

2000g

1750g

1500g

1250g

1000g

750g

500g

250g

San Remo Fettuccine

5cm (63g)

6cm (69g)

7cm (74g)

The truss is tested with different vertical members with various height. The horizontal members are kept constant. The diagonal member length is dependent on the vertical members’ height.

Height of Truss

đ??żđ?‘œđ?‘Žđ?‘‘ ) đ?‘€đ?‘Žđ?‘ đ?‘ đ?‘œđ?‘“ đ?‘‡đ?‘&#x;đ?‘˘đ?‘ đ?‘

Efficiency, E= (

5cm

39.68

6cm

32.61

7cm

23.64

The truss with 5cm vertical members is stronger compared to 6cm and 7cm, it can withstand 250g of load.

From the height test, all of the trusses failed and collapsed at the similar parts of the members.

Referring to the diagram below, the truss members will be strengthen by using double layers for the next test.

10

B) Different design of trusses Load Test

3000g

2750g

2500g

2250g

2000g

1750g

1500g

1250g

1000g

750g

500g

250g

Trusses Design

6cm (69g) Warren with verticals

6cm (68g) Howe

6cm (71g) Pratt

Types of Truss

đ??żđ?‘œđ?‘Žđ?‘‘ ) đ?‘€đ?‘Žđ?‘ đ?‘ đ?‘œđ?‘“ đ?‘‡đ?‘&#x;đ?‘˘đ?‘ đ?‘

Efficiency, E= (

Warren with verticals

32.61

Howe

22.05

Pratt

24.64

With the members of same height and length, different types of trusses were tested. In a nutshell, Warren truss with verticals is the strongest among the 3 trusses, it has the highest efficiency.

11

3.0 Construction of Bridge

Step 1 The bottom chord is built by a few stacking layers of fettuccine to form I beam.

Step 2 Vertical members of the truss are attached to the bottom chord from the middle.

Step 3 Top chord of the truss was then attached to the vertical members.

Step 4 The remaining vertical members are added to the truss bridge.

Step 5 The diagonal members are added into the truss members.

Step 6 Step 1 to step 5 is repeated to build the opposing side of the truss bridge.

Step 7 The horizontal members that connects both sides of the truss bridge are added together with the core at the bottom chord.

Step 8 Lastly, the horizontal members are also added at the top chord.

12

4.0 Bridge Testing 1.

Bridge Width=5cm

The bridge broke at the middle part.

Load=2500g Efficiency =2500g/63g =39.68

No I beam was used in the construction.

50mm 450mm

2.

Bridge Width=5cm Load=2250g

Different height of bridge used in 1st and 2nd bridge to test their strength.

Efficiency =2250g/69g =32.61

60mm 450mm

3.

Bridge Width=5cm

Different designs of trusses were constructed.

Load=1750g Efficiency =1750g/74g =23.65

Bottom chord was changed to I beam

50mm 450mm

13

4.

Bridge Width=4cm

Warren truss bridge are added with I beam.

Load=5000g Efficiency =5000/70 =71.43

Some vertical members are double layers.

Only the middle member that is hanging hook breaks.

40mm 450mm

5.

Bridge Width=4cm Load=5800g Efficiency =5800/77 =75.32

More vertical and diagonal truss members are added.

Some vertical members are double layers.

Only the middle member that is hanging hook breaks.

40mm 450mm

6.

Bridge Width=4cm

6 horizontal members support at bottom cord.

Load=4800g Efficiency =4800/70 =68.57

The middle part of the truss breaks in halves.

50mm 450mm

14

7.

Bridge Width=4cm Load=3000g

The I beam was left overnight and became brittle.

Efficiency =3000/70 =42.86

The members to hang S hook is too small. Thus, the S hook breaks the bridge.

Bridge Width=4cm

The I beam was left overnight and became brittle.

40mm 410mm

8.

Load=3000g Efficiency =3000/70 =42.86

The warren truss ends before the table edge.

Hence, the truss breaks easily.

50mm 410mm

15

9.

Bridge Width=4cm Load=5000g

The truss breaks because of S hook exerting force horizontally.

Efficiency =5000/7 =71.43

Considered increase the width of members to place S hook.

Bridge Width=4.5cm

The span of gap to place the bridge is reduced from 350mm to 300mm

50mm 410mm

10.

Load=11200g Efficiency =11200/71 =157.75

50mm

The S hook is not directly hang at the truss member.

Ropes are used to tie on the truss and hanged the S hook.

The truss bridge break at the members that hanged S hook.

410mm

16

5.0 Structural analysis of the Bridge Truss system of the final model bridge

17

18

19

20

21

The internal forces for all the vertical members are 0. However, the horizontal and diagonal members are either in tension or compression. From conclusion, the vertical members are redundant in the truss system with the load exerted at point M.

22

6.0 Conclusion Throughout the whole project, we have constructed 9 experimental fettuccine truss bridges and one final fettuccine truss bridge. For every structural failure, we investigated the construction of fettuccine truss bridge to improvise the strength of the fettuccine truss bridge. From what we learnt from experience, we are able to construct the best fettuccine truss bridge with the highest efficiency. Our final model achieves an efficiency of 157.75 and it is able to withstand 11kg of load.

During the process, we are able to learn knowledge and constantly improve our understanding on truss bridges. This project had trained us to be attentive to the details of every test and construction. We learnt about the different types of perfect trusses, load distributions and also able to identify the types of internal forces in the truss members. Other than that, we also realized that every mistake and failure are the stepping stones for our next success.

In a nutshell, this project is an eye opener to all of us. We learnt a lot about structural design of a bridge where both aesthetical and structural value are equally significant. The understanding of structural system is definitely beneficial to all of us in the future.

23

7.0 References

Boon, G. (2011, April 1). Warren Truss. Retrieved May 2, 2016, from http://www.garrettsbridges.com/design/warren-truss/ How to Build a Spaghetti Bridge. (2016). Retrieved May 1, 2016, from http://www.wikihow.com/Build-a-Spaghetti-Bridge Mettem, C. (2011). Timber bridges. Abingdon, Oxon: Spon Press.

Schweige, P. (1999, September 19). Fettuccini Physics Contest. Retrieved April 24, 2016, from http://teachertech.rice.edu/Participants/pschweig/lessons/BridgeProject/pastacontest/page4.html Shiva. (2015, May 22). Perfect Truss & Imperfect Truss. Retrieved May 12, 2016, from http://semesters.in/perfect-truss-imperfect-truss/ Tension and Compression. (2016). Retrieved April 25, 2016, from http://science.howstuffworks.com/engineering/civil/bridge2.htm Truss Bridge - Types, History, Facts and Design. (n.d.). Retrieved May 12, 2016, from http://www.historyofbridges.com/facts-about-bridges/truss-bridge/ Warren Truss Bridge | Definition | Advantages and Disadvantages. (n.d.). Retrieved April 25, 2016, from http://www.transtutors.com/homework-help/civil-engineering/trussapplication/warren-truss/

24