1. Problem statement:
Design and fabricate a suspension- bridge through popsticks.
2. BRIDGE SPECIFICATION:
2.1 Structure details
This type of bridge will comprise of the following five parts:
· Towers
· Main suspension cable
· Anchorage
The deck of the bridge is supported by the main suspension cables which in turn rest on the towers which bears the compression stress. The main suspension cables are anchored to the anchorages on both sides of the bridge.
- 2.2 Construction details
1. Construction of a suspension as well as movable bridge involves sequential construction of these major components: the towers, cable anchorages, the support cables and the static deck structure
2. The structure required in the competition will have a minimum of four towers and total length of the suspended bridge should be in between should be of 1000 mm in length.
3. The cable anchorage will be provided by the organizer. They will be C shaped clamps fixed in the towers of 200 mm height at the top.
4. The length of the bridge extending outside the end tower and the anchorage will be 125 mm on each side.
5. All the cables in the suspension bridge will be made up of single layer of string. Use of multiple layers of strings is not allowed.
6. The string can either be glued to the deck or you can knot the string.
7. Total number of cables between the two anchorages (1250 mm clearway) should not more than 126 i.e. a maximum of 63 strings on each side is allowed.
8. The width of the bridge will be equal to the 200mm. The width will be measured at any length of the bridge.
9. The minimum clearance of the bridge from the bottom should be 200 mm.
10. The suspension bridge must have a level, seamlessly constructed roadway.
2.3 Materials specifications
1. Popsicle sticks and cotton threads should only be used to build the structure.
2. Sticks can be joined using threads or glue or both; however glue can’t be used to reinforce the individual sticks by applying on the free surface.
3. The max. diameter of thread should not be more than 1mm.
4. The towers should be made of wood only.
2.4 Plot specifications
1. Two steel sections are provided to which clamps will be attached, they will be 1250mm apart at their closed pts. They will be 225mm high
2. Of the total 4 clamps 2 will be attached on either section.
3. The positions of slots for fixing of towers are as shown in fig.
4. All the above mentioned setup will be fixed in a tank.
3. COMPETITION DETAILS:
3.1 Testing conditions:
1. Prior to the competition the participants will be given time to assemble and fix the structure in the plot.
2. Each team will be given 5 trials to move the 5different weights across the bridge
3. The weights will be of 7,8,9,10,11,12,13,14,15,16,17,18,19 and 20kg
4. Participants will decide how much weight will be placed.
3.2 Scoring criteria:
1. Strength ratio is the ratio of maximum weight fully passed and the self-weight of bridge
2. Strength ratio=(maximum weight fully passed)/(self weight of bridge)
3. The team with maximum strength ratio will be declared as winner
3.3 Definition of failure:
1. The structure is defined as failed if it is unable to satisfy any of the above conditions
2. Any part of the structure breaks or cracks i.e. strings, popsicle sticks, etc. or is in not in a position to carry load
4.RULES:
1. The shape of structure could be any shape satisfying the above factors.
2. The structure will be weighted first and no changes in it will be allowed after weighing and between rounds
3. If the structure fails to satisfy any of the above constraints it will be rejected
4. Any team not ready during the time specified will be rejected
5. Judges decision will be final and binding to all.
5. TEAM SPECIFICATIONS AND ELIGIBILITY CRITERIA:
1. Number of participants in a team should not be more than four
2. Students from any institute can form a team
The organizers reserve all the rights to change or modify any or all the rules as they deem fit
Any changes will be highlighted on the website
