Dr. Gajendra Tulsian

  



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Bridge Building


OBJECTIVE

The objective is to build a balsa wood bridge that weighs 110g or less, and supports a load. The bridge supporting the largest weight, wins. Teams of 1 to 3 students can enter this event.

CONSTRUCTION RULES:
  • Total mass of the bridge plus cement shall not exceed 110.0 grams.

  • The bridge shall contain no element wider than 0.953 cm nor thicker than 0.635 cm commercial balsa stock. Two or more pieces, each separately qualifying, may be attached without violating this requirement.

  • Balsa wood and glue are the only materials that can be used.

  • No fastening mechanism except mechanical interlock of the balsa pieces or gluing with commercial glue is allowed.


DESIGN RULES:
  • The bridge shall allow a 10.0 cm cube to slide underneath its span without touching.

  • The bridge shall allow a 40.0 cm wide 2.0 cm tall board to slide underneath without touching.

  • The bridge must be "free standing."

  • The bridge must provide an approximately horizontal "roadway" above the 10 cm level and extending at least 40 cm upon which a small car of the Hot Wheels or Matchbox variety can roll if given a slight push by hand.


TESTING:
  • The bridge will be placed upon a test stand which will consist of two flat, level surfaces, which the bridge will span.

  • Two one-inch (1.27 cm radius) dowels will be rested on the roadway separated by 6.0 cm and the test block (10.5 cm long X 3.68 cm X 2.54 cm high) will be rested upon them. Either a single steel rod on the middle of the test block, or two rods 6.0 cm apart (thus 3.0 cm from center in either direction) will be rested on the block extending beyond the sides of the bridge in either direction. Load will be applied to the bridge on these projecting rods.

  • A hopper will be hung from the rods and weight added slowly.

  • Testing will end, either at a catastrophic collapse of the bridge or at any loud crackling sound indicating that collapse is imminent.

Balsa Wood Bridge

Office: (386) 506-3779
Cell: (386) 569-7773

Daytona State College
School of Biological & Physical Sciences
1200 W International Speedway Boulevard
Daytona Beach, FL 32114

Gajendra.Tulsian@DaytonaState.edu