Critical Load

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

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

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.

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

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”:

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

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