Project 2: Straw Bridge

1. Project 2: Straw Bridge Situation: We should across the river safely. Design brief: To design and make a straw bridge model for practicing purpose Group :3 or4members Duration:3 cycles

2. Project 2: Straw Bridge Material provided:plastic straws – 40 (200mm long) Colourless Self Adhesive Tape Requirement : 1) You are free to design the structure. The product must be made of plastic straw and is fastened by colourless self-adhesive tape.

3. 100mm >500mm Project 2: Straw Bridge 2) The bridge model should be 100mm wide and over 500mm long. This is a sample only. Don’t copy!

4. 500mm 175mm 180mm Testing platform Project 2: Straw Bridge

5. Project 2: Straw Bridge Requirement : 3) Straws parallel overlapping design is not allowed.

6. Juice Pack Project 2: Straw Bridge Requirement : 4) Weights are placed one by one on the straw structure model until it breaks down so as to test the loading ratio. (Weight: 250ml juice pack, @275g)

7. Loading Ratio = Maximum Loading Weight of the bridge model Project 2: Straw Bridge Requirement : 5) Weights are placed one by one on the bridge until it breaks down so as to test the loading ratio.

8. Project 2: Straw Bridge Requirement : 6) The bridge should not consist any component touching the ground of the testing platform and nothing can be used to fix the model on the platform.

9. Project 2: Straw Bridge • Testing procedures: • Measure the weight of the bridge model by the electronic balance.

10. 500mm Testing platform Project 2: Straw Bridge Testing procedures: 2) Place the bridge model on the testing platform which is designed for holding a bridge of over 500mm long.

11. Project 2: Straw Bridge Testing Methods: 3) Place weights one by one on the central of the bridge model until it breaks down. Testing sample

12. Project 2: Straw Bridge Testing Methods: 3) Place weights one by one on the central of the bridge model until it breaks down. Testing sample

13. Loading Ratio = Maximum Loading Weight of the bridge model Project 2: Straw Bridge Testing procedures: 4) Count the number of weights used. 5) Calculate the loading ratio. Higher loading ratio is recorded, higher mark will be given.

14. Sample http://pghbridges.com/basics.htm Project 2: Straw Bridge Information: Search the information about frame, structure and bridge via internet.

15. Project 2: Straw Bridge Design consideration: Weight of the bridge model Stability Information Solution Bridge structure Special features of straws

16. Project 2: Straw Bridge Suggested Procedures Design Considerations Initial Ideas Final Idea Solution Make a bridge model (Cycle 2) Testing (Cycle 3) Evaluation (Cycle 3)

17. Loading Ratio Size Marks < 5 Not fit 0 5 and <10  - - - 1 10 and <15 Fit in 2 15 and <25   - - -  - - - 3 25 and <35   - - - 4 35 and <45   - - -  - - - 5 45 and <55   - - - 6 55 and <65   - - - 7 65   - - - 8 Total 8 + 2 Project 2: Straw Bridge Assessment:

18. 35 and <45 5 Project 2: Straw Bridge Assessment: e.g. The model’s size fits the testing platform Weight = 25g Loading = 4 x 275g = 1100g Loading ratio = 1100 / 25 = 44 Marks = 2 + 5 = 7

19. Weights Bridge model Range = 500 mm Project 2: Straw Bridge Information:

20. Weights Bridge model Range = 500 mm Project 2: Straw Bridge Information:

21. Weights Bridge model Range = 500 mm Project 2: Straw Bridge Information:

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