Project Objective:
The objective of this event is to evaluate student knowledge of statics, force vectors, and balancing torques. Model bridges are intended to be simplified versions of real-world bridges, which are designed to accept a load in any position and permit the load to travel across the entire bridge.
Physics Concepts:
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- Students will investigate the various forms of stress including:
- Compression
- Tension
- Shear
- Students will examine the relationship between stress and strain and be able to make informed decisions about their bridge design according to these principles.
- Students will investigate the concept of torque, moment arm, and beam stresses.
- Students will use the concept of vectors to calculate the directions and magnitudes of two dimensional forces.
- Students will resolve two-dimensional vectors into their components and calculate the magnitude and direction of a vector from its components.
- Students will solve two-dimensional problems involving balanced forces (statics).
- Students will investigate the various forms of stress including:
Specifications:
- The bridge must span a minimum gap of 50 cm and should not exceed 60 cm.
- The loading platform is 10 cm wide, 10 cm tall and 45 cm long. It has two 1.5 cm by 7 cm slots milled 8 cm apart in the center. The loading bucket hangs from two “J” hooks inserted in the platform. The platform MUST rest on a minimum of five interior floor beams of the bridge.
- No portion of the bridge may project below the elevation of the support surfaces.
- The bridge will be centered on the support surfaces.
- The loading plate will be placed at the specified loading location.
- The load will be applied from below, as described above.
Performance Metrics:
- Strength:
The bridge will be statically loaded with a weight of 50 N or until failure occurs. - Efficiency:
Bonus points may be awarded to the designs that support the most weight per gram of structure.
Materials:
- All the component materials will be made from supplied manila folder stock. You may supply colored folders as you wish to personalize your bridge.
- White PVA glue and mandrel materials will be supplied. No other adhesives are allowed.
- No other materials may be used. The bridge may not be stained, painted or coated in any fashion with any foreign substance including PVA.