Physics Olympics
Paper Bridge
Instructions Poster - Simulation - Grading


Paper Bridge Record
487 kilograms
(1071 pounds)

Overview - Each student will enter a Paper Bridge and Full Scale Drawing with Force Analysis Poster to compete in Physics Olympics.  Each student is to complete his or her project according the design requirements and due dates. Students may bring their project to class prior to competition day for approval and inspection by his or her teacher as well as to check their project for minimum supporting mass requirements.

Purpose - To construct a bridge from paper and glue that will support the heaviest load (minimum supporting mass requirment is 5 kilograms).

ATTENTION PARENTS AND STUDENTS

The bridge project requires the fabrication of bridge components which may require the use of hand or power tools. Common tools used are scissors, knife, electric drill and handsaw or power saw. Follow all manufacture safety guidelines and directions including the use of safety goggles. Tools should be used under adult supervision.

The bridge project requires the fabrication of bridge components which may require the use of white glue. Follow all manufacture safety guidelines and directions.


Requirements
1. The bridge is to be constructed from white 8.5" X 11" or 8.5" X 14" computer/zerox paper
NO OTHER PAPER PRODUCTS ARE ALLOWED.

2.
ONLY Elmer's glue (generic white glue) or Elmer's glue stick (generic glue stick) are allowed. Paper mache' is NOT allowed.

NOTE - White glue will not discolor or change the opaque characteristic of the paper. Any white glue or glue stick that discolors the paper is NOT allowed.

3. Tape of ANY type is NOT allowed.

Allowed Glues

Key to Joint Construction

Since most bridges will fail at the joints, joint construction should demand maximum attention. Although researching joint construction is an excellent idea, that alone is not enough. One should experiment with various joining techniques before deciding on the best technique for that person. Due to differing mechanical skills, a joining technique that is great for one student may be difficult for another. Excessive use of tape and adhesive are not the key to building a robust joint. Tape and adhesive should be used sparingly. Joints that are mitered and fit flush along with reinforcement techniques have proven to be superior to poorly engineered joints reinforced with excessive amounts of tape and adhesive. Reinforcement techniques may include but are not limited to the following: pinning, slotted connections or plating. What will work best for you? Experiment and find out!

4. Glue restrictions and usages are as follows:
Allowed:
- Glue may be used to laminate sheets of paper together.
- Glue may be used to bond 2 or more members together.
- Glue may be used to bond the roadway to support members.
Disallowed:
- No more than 50% of the bridge's truss surface area and roadway may be covered/coated in glue.
- No facades may be used to hide excessive glue.

5. Member bonding restrictions are as follows:
- Glue used for the purpose of bonding two of more skew or perpendicular members together.may not extended more than 2 cm beyond the joint.
- There is no member bonding restriction for the joining of parallel members.

Key to Member Construction

Second to joint construction, member construction should demand considerable attention. Although researching member construction is an excellent idea, that alone is not enough. One should experiment with various sized and shaped members before deciding on the best design for that person. Due to differing mechanical skills, a member design that is great for one student may be difficult for another. Bridges that take compression and tension into consideration and build the appropiately sized and shaped members are superior to bridges with uniformly constructed members. What will work best for you?
Experiment and find out!

6. The bridge shall be free-standing and must SPAN two level surfaces which are half a meter apart. It is recommended that the minimum length of the bridge be no less than 54 cm.

7. The bridge MUST incorporate a truss design. Students MAY select one of the basic truss designs illustrated below or DESIGN THEIR OWN unique truss design. If a student selects to design their own unique truss design, it is recommended that the design be reviewed by his/her teacher. NO inverted bridges (trusses are beneath the roadway).

Bowstring
Camelback
Howe
     

Pratt
Waddell "A"
Warren

8. All students are REQUIRED to use the bridge design simulation shown below. For the bridge design simulation, Click here.

9.The support for the bridge shall be from the top of the level surface. The edges of the level surface cannot be used in any way for support.

ACCEPTABLE
(table provides only vertical support)
UNACCEPTABLE
(table is providing horizontal support)

10. The bridge must include a decking of paper to provide a suitable road surface at least 5-cm wide across the full span of the bridge. Four conditions must be met:
- The deck may not have any gaps.
- A block of wood 5-cm x 5-cm x 1-cm representing a car must be able to move along the length of the deck unobstructed from end to end.
- The highest point of the deck may be no higher than 5 cm above the tabletop to allow for loading zone reinforcement.
- The deck of the bridge must either be flat across its entire span or inclined upwards towards the loading zone.

Key to Loading Zone Construction

Finally, consider reinforcing the loading zone. A poorly designed and reinforced loading zone may result in structural failure ONLY at the loading zone. This unfortunate over site may leave the rest of the bridge structurally intact. Loading zone reinforcement should not be limited to excess use of glue but may include the construction of additional members (i.e. layers and/or joint construction). Remember the entire weight supported by the bridge is applied at the loading zone. What will work best for you?
Experiment and find out!

11. You must incorporate a "loading zone" at the midpoint of the span along the centerline of the bridge. The loading zone must be 5-cm x 5-cm and receive a flat block of wood called the loading platform. A half-inch hole must be located at the center of the loading zone and pass completely through the deck and all bridge supports beneath the deck. A bolt will be inserted through the hole from beneath the deck and attached to the loading platform. Your instructor will provide the bolt and loading platform.

The purpose of these pictures is to aid in the explanation of the bridge project requirements.
These pictures are NOT intended to be examples of quality construction or design.



Loading Platform

The purpose of these pictures is to aid in the explanation of the bridge project requirements.
These pictures are NOT intended to be examples of quality construction or design.

12. The maximum vertical height of the bridge, from the highest point in the structure to the lowest point, cannot exceed 30-cm.

13. The MASS of the bridge shall not exceed HALF A KILOGRAM.

14. The bridge may not be COLORED in any fashion (paints, canyons, markers, etc.). The color of the bridge may reflect the color of the paper and tape/glue used.

15. Failure to meet these specifications will result in grade penalities. See grading rubric for details.

Helpful Hints
How Stuff Works
Force Lab
ABC's of Bridge Design

Topics on Bridge Construction

Bridge Testing
1. The load will be applied on the roadway surface at the mid-span along the centerline of the bridge by means of a loading platform.
2. A mass cradle will be attached to the loading platform and be suspended below the bridge.
3. Mass will be loaded into the mass cradle until structural failure is reached.
4. The final grade will be determined by the greatest mass held without partial or complete structural failure. Refer to the bridge rubric for details.

Poster - Simulation - Grading

This activity may be reproduced in any form for use in a classroom, but under no
circumstances may any portion be reproduced for publication without written consent.