Investigative Science Skills
SCHOOL OF SCIENCE AND TECHNOLOGY, SINGAPORE
INVESTIGATIVE SKILLS IN SCIENCE
Names: Bryan Ho, Ang Yue Sheng, Tan Jian Qing and Javier Ng
Group Reference: E
1. Indicate the type of research that you are adopting:
[ ] Test a hypothesis: Hypothesis-driven research
[ ] Measure a value: Experimental research (I)
[ X ] Measure a function or relationship: Experimental research (II)
[ ] Construct a model: Theoretical sciences and applied mathematics
[ ] Observational and exploratory research
[ ] Improve a product or process: Industrial and applied research
2. Write a research proposal of your interested topic in the following format:
Title: The Investigation of the factors affecting the stability of a bridge under extreme weight.
A. Question being addressed
Many bridges around the world has collapsed due to many factors. Some bridges collapsed due to the material used in the bridge. One example from Wikipedia is the Tuo River bridge in Fenghuang, Hunan which collapsed on 12 August 2007 as shoddy materials was used to build the bridge, in an effort to cut costs. Other reasons for bridges to collapse is due to the design of the bridge, like the Myllysilta bridge in Turku, Finland which collapsed on 6 March 2010, according to Wikipedia. A structural failure of both piers led to the bridge to bend 143 centimeters, causing the bridge to collapse.
Thus, there have been many measures to allow bridges to be more sturdy, such as ensuring proper initial construction, more thorough inspections, painting protective coatings and paints, such as epoxy resins and polyurethanes onto bridges to prevent corrosion from happening. These measures work towards reducing the chances of the bridges from collapsing due to different circumstances.
Other than these measures which have already been implemented in existing bridges, what other ways are there to reduce the chances of the bridge collapsing? Does the design actually help to increase the amount of weight the bridge can hold? What design has the greatest efficiency? Through our research, we aim to find out the answers to these questions.
We aim to find out if the design of a bridge affects the maximum loading capacity of the bridges. We intend to do so by building 3 bridges with different designs with ice cream sticks for to see which bridge design would have the highest efficiency.
Our independent variable:
-the structural design of the bridge
Our dependent variable:
-the amount of weight the bridge can sustain before it collapses.
Our controlled variables:
-type of material used to build the bridge (balsa wood)
-the amount of glue that is applied onto the bridge
-the height of the bridge
-the length of the bridge
-the thickness of the material.
The hypothesis is:
-The bridge design with the X-shaped truss will be able to withstand the most amount of weight as compared to the other designs.
After compiling and comparing our data, we expect to find the bridge with the truss shaped like an X to support weight the most and we expect the conclusions we make to be supported by other previously-completed research papers.
C. Description in detail of procedures
-Ice Cream sticks
-White multipurpose glue
-Weights (2.5kg, 5kg, 10kg)
-Strong nylon strings
- Use a bridge simulation software (West point bridge design 2014: 2nd edition) to virtually build the bridge design.
- Plan out the designs in the bridge simulation software (West point bridge design 2014: 2nd edition).
- Choose the 3 best designs from the bridge simulation software (West point bridge design 2014: 2nd edition) and plan out the physical design for the bridge.
Building the bridge
- Buy the necessary materials needed to build the bridge.
- Refer to the plan of the bridges for building the 3 bridges.
- Build 3 identical bases of length 69cm and width 11.5cm.
Placing ice cream sticks onto the structure of the bases
Design of final base
- For bridge 1, it acts as a constant, therefore there will be neither deck nor truss on it.
Sticking the sides of bridge 1
Glueing of bridge 1
Top view of completed bridge 1
Side view of completed bridge 1
Other side view of completed bridge 1
3/4 view of completed bridge 1
- For Bridge 2, build a through truss.
- For bridge 3, build a deck truss.
- To make a through truss for bridge 2, 48 pairs of ice cream sticks in the shape of an X are to be made.
The X-shape ice cream sticks
- Stick 2 pairs of 6 individual Xs together to form the truss of the bridge.
The design of the truss
- Stick the truss design to the side of the base of bridge 2
Sticking the design to the sides of the bridge
- Leave the truss to dry for 24 hours.
- After the truss is dried, stick ice cream sticks on top of the bridge to make the top of the bridge. Wait for it to dry. When it is dry, bridge 2 is completed.
The drying process for the top of the bridge (bridge is laying by the side for this photograph)
Top view of completed bridge 2
Side view of completed bridge 2
Other side view of completed bridge 2
3/4 view of completed bridge 2
- For bridge 3, stick 4 ice cream sticks that are made up of ice cream sticks which are glued together to form 17.25cm and a cross made up of ice cream sticks which are glued together to form 17.25cm sticks onto the side for the base to form one side of bridge 3.
Planning of the sides for the 3rd bridge
The side of the third bridge (note that protruding edges at the top of the sides were not sawed off yet)
- Saw off the protruding edges at the top of the sides.
- Repeat step 15 and 16 for the other side of bridge 3.
- Stick the sides of bridge 3 to the base of bridge 3.
The sticking process of the side of bridge 3 to the base of bridge 3
- Leave the sides to dry for 24 hours.
- When the sides have dried, stick ice cream sticks at the bottom of the bridge to create the bottom of the bridge. Wait for the bottom to dry. After the bottom of bridge 3 has dried, bridge 3 is done.
Top of completed bridge 3
Side of completed bridge 3
Other side of completed bridge 3
3/4 view of completed bridge 3
- Leave all the bridges for 48 hours before testing them.
Testing the bridge
- After 48 hours, measure the weight of bridge 1 using a weighing machine.
Weight of bridge 1
- After measuring the weight of bridge 1, place bridge 1 onto a bridge testing machine.
Bridge 1 on the bridge testing machines
The support beams for the bridge testing machine
- Place a 2.5 kg weight on the bridge every 10 seconds if the bridge shows no sign of cracking, breaking or collapsing and record the entire process on video.
- Continue step 24 until the bridge cracks, breaks or collapses.
Broken bridge 1
- Record the weight that the bridge broke under and calculate the efficiency (the mass that the bridge is able to hold divided by the mass of the bridge) of bridge 1.
- Repeat steps 22-26 with the other 2 bridges designs.
Testing of bridge 3
- Compare the datas recorded for the 3 different designs (Weight of the bridge, weight the bridge can hold, efficiently of the bridge).
- Collect the data and represent them in a table.
- Plot a table of values of mass of bridge, the maximum mass of bridge, and the efficiency if the bridge.
- Efficiency is defined as the mass that the bridge is able to hold divided by the mass of the bridge.
- The bridge with the highest efficiency can then be found.
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Moore, R. (2013, March 28). Understanding Bridges. YouTube. Retrieved July 8, 2014, from http://www.youtube.com/watch?v=hwzXXXUAKVU
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