RULES:

1. The contest will be for students only. The objective is to design and build a double decker composite bridge using an assortment of pultrusions, cores, fabrics and other materials supplied in kit form. Minimum bridge dimensions will be 24" long by 4" wide. During testing, the bridge will be supported by 2 posts placed 23" apart. The bridge will be center loaded on the bottom deck and have a distributed load on the upper deck. The most weight efficient bridges will be judged winners.
2. The contest is divided into four material categories. These are Kit and Non-Kit Carbon, Kit Glass, and Kit Natural Fiber. Kit will be limited to the materials supplied in the kit or "equivalent materials" as allowed by the judging committee. Non-Kit will include any other materials available to the competing team. The Natural Fiber bridge cannot use any glass or carbon fiber. Nor can it use any wood not supplied in the kit. The GLASS bridge cannot use any carbon fiber. The CARBON bridge can use glass and carbon and natural fiber. No boron fiber is permitted (boron can only be used in the Wing contest).
3. A kit consisting of the pultrusions and fibers, fabrics, honeycombs, adhesives, foam cores, and epoxy resin will be shipped to all participants by mid March, 2006. The kit will specifically contain uni-directional and bi-directional carbon, glass, and natural fiber fabrics and mats, and a variety of glass and carbon braids. It is anticipated that by mid-February, a list of all fiber products to be shipped will be made available to all registrants. The list will contain information sufficient for preliminary design calculations.
4. Materials: "Equivalent materials" for the kit class must be approved in advance of the testing by submittal of an equivalent materials list in writing. If the judging committee does not approve the equivalence, then the bridge becomes a Non-Kit entry (for the carbon category) where the use of any composite or non-composite material is permitted.
5. Bridge Geometry: The overall bridge envelope is given in the figures. Minimum bridge dimensions must be 24.0" (length) and 4.0" (width). Lower roadway surface across a centered 3.5" width must be flat and continuous and opaque and must be constructed so as to support a 3.5" wide vehicle. The bridge may be arched but the lower roadway surface may not rise more than 4" above the top of the end support posts. The upper roadway surface must also be flat across the width and continuous across the width and may be arched. There must be a minimum 4 inch clearance between the top of the bottom roadway surface and the bottom of the top roadway surface. The upper bridge will have a centered 1.5 inch diameter hole through the surface so that the test machine loading rod may pass through to apply load to the lower surface. Also the upper roadway must be constructed so as to support a 50 pound distributed load in the form of either 4.5 inch long rectangular steel bars or four 12.5 pound shot bags, to be determined later. Total bridge height from the top of the bottom road surface to the top of the upper road surface must be less than 9 inches. The width of any structure should be less than 6 inches to insure fitting with end posts. See figures.
6. All reinforcement for the lower level must be contained in a 2.5 x 6.0 inch envelope as shown in the figure, except forany superstructure that may be constructed on the sides (outside of the 4.0 inch center). The envelope may be arched.
7. The bridge weight, WT, will be measured immediately prior to test. The 50 pound upper load surface weights will be applied first. A member of the team will apply the distributed load over the entire upper surface by hand. The bridge will be mechanically loaded at center span. Deflection W will be measured by crosshead motion. Maximum load P is defined as the mechanical load at failure or the mechanical load at 1" crosshead deflection, whichever event occurs first. Note: The upper surface must maintain its integrity as the distributed load is applied. The "tunnel" clearance under load must be at least 3 inches or the bridge has failed.
8. Bridge efficiency is computed as P/WT. The bridge with the highest value of P/WT in each category shall be judged the winner. A loading machine having a 20000 pound capacity will be used.
9. Load testing will be conducted on the exhibition floor during open exhibition hours on Tuesday, May 2. Each bridge will be loaded to failure once. No retests are permitted. A team may submit only one bridge for testing per entry fee. Multiple entries are permitted.
10. All student team entries must also submit a poster presentation highlighting some material, process and/or design aspect of their bridge. Bridges without posters will be tested but will not be eligible for prizes. Each bridge requires a poster. The posters must be submitted by 10 AM Tuesday at the "Bridge Prep" room near the conference registration area. The posters will be prominently displayed in the main registration area on Tuesday, Wednesday and Thursday. A committee will judge the posters, based on technical merit. General guidelines for poster presentations are available from the Business Office. NOTE: Posters may not be removed until Thursday afternoon. If you want it to be returned but have left early, please provide an addressed envelope or shipping container to the staff.
11. Multiple prizes will be awarded for the best efficiencies in each category. In addition, prizes for best posters will be given out. All prizes will be awarded at the Wednesday morning student awards breakfast. Door prizes will be awarded on Tuesday 5 PM on the balcony above the registration area. (Same as last year.)
12. The entry form along with a $40 fee to defray contest costs must be received no later than March 10, 2006.
13. A useful website has been developed by P.Joyce at USNA. Please note that it was developed for earlier contests and there are differences with the present contest.

Example #1
Example #2
Example #3
Registration Entry Form