1. Critical Load

2. Learning Objectives Learn about structural engineering
Learn how to reinforce the design of a structure to hold more weight.
Use mathematical calculations for testing
Practice communication skills through written and oral exercises

3. Critical Load Great Structures of the World Millau Viaduct
Millau, France
World’s Tallest Bridge
2460m long 434m pylon height 270m road height
December, 2004

4. Critical Load Great Card Structures of the World Skyscraper of Cards
2010 World Record House of Cards
Made of 218,792 cards, measuring 10.39m long, 2.88m tall and wide. No glue or tape; just cards
Built by Bryan Berg in 2010
Venetian Macao-Resort-Hotel in Macau, China, on 10 March 2010.

5. Critical Load What is Critical Load? Force is placed on a structure
Structure can support up to a certain force created by the weight
At a certain point, the structure will fail, breaking
The maximum force the structure can sustain before failure is known as the “Critical Load”
Force
Force

6. Critical Load Efficiency
A high critical load is not the only parameter to consider
Is the best bridge made by filling a canyon with concrete? It certainly would have a high critical load!
Consider also the weight of the structure
Lighter is better, given the same critical load
These two parameters are combined in an “Efficiency Rating”:

7. Critical Load Your Turn Groups of 2 Up to 10 cards + 1m tape
Devise a plan to build a load bearing structure
Should have a flat top
Support load with base area of 10x10cm at least 8 cm above the table
No altering of cards allowed – just tape!
No wrap-ups of tape
Tape is used to connect cards only

8. Critical Load Your Turn
Your efficiency rating: [Load at Failure] / [# of cards used]
Predict what the rating of your design will be
Build your design
Test it!
Discuss improvements, then repeat exercise for a second design