6. Bridge Design

This one is nice! J You will see J

In this activity, you will construct a simple span bridge and you will use an interactive computer simulation model to design a truss bridge to carry the load of a truck. You will also build a scale model of their bridge design.        

 Looks nice!  Doesn’t it?

OK! Let’s see!

Background:

Bridges have been used for over 3,000 years to cross rivers and valleys.  Their design ranges from simple planks, to complicated arches and suspension bridges.  They are used in both urban and rural areas.  

 

Paper Bridge Challenge:

 

To build a bridge that can support 50 pennies, using a single sheet of paper and five paper clips that can span a river 23 cm (about 8 inches) wide and withstand the weight of at least 50 pennies. The bridge will rest on top of supports and cannot be taped or attached to the books, table, or desk.

 

 

 

 

 

 

 

 

Instructions

 

 

6a. Paper Bridge Challenge

1.      Divide your team into groups of two. Have one student in each group collect the materials.

 

2.    .Before starting ask yourself :  What do you think might work?

 

3.    Once the group has completed a bridge design, set it up across the book supports, placed 23 cm apart. One of the group members places the pennies on the bridge until it collapses. The group should record how many pennies their bridge supported.

6b. Computer Simulation Model

4.    Run the West Point Bridge Designer program for each group member.  You are able to change the size and type of steel members. Print out your results and cost of construction.

 

6c. Build a model

5.    Using K’nex, build a model of the bridge you designed on the computer, using the blueprints you printed out.  Change your original design a little if you need to.

6.    Answer questions on worksheets

 

 

Discussion

Define the following terms:

1.      Tension

2.    Compression

3.    Bending

4.    Shear

5.    Torsion

6.    Cable

7.    Strut

8.    Beam

9.    Arch

10.Slab

11. Pier

12.Abutment

Answer following questions:. 

·        Why do we need bridges?

·        What do bridges look like?

·        What shapes have you seen in bridges?

·        What are qualities a bridge should have?

·        Describe how the bridge behaved.

·        Was it as strong as you thought?

·        Can you identify where their bridge failed?

·        How could they redesign the bridge to be stronger?

·        Are there similarities in the designs of each group’s strongest bridge?

 

Additional Information:

“Web sites” for more information:

http://bridgecontest.usma.edu/

http://www.nireland.com/bridgeman/Dictionary.htm

http://www.richmangalleries.com/bridges.htm

http://www.lyndonroad.com/pphotos.html

http://www.ci.nyc.ny.us/html/dot/html/bridges/opener.html#swing_span