Building Bridges Become an engineer!
Competition You are a group of engineers challenged to make a new bridge across the Thames to the houses of parliament. The government has very little money, so you have limited materials. The best bridge will win a contract to make their bridge.
Rules Design and make a bridge to cross a 30cm gap across two stools, using 40 straws. Sticky tape can not be wrapped around and around. Test the maximum mass the bridge can take. The bridge that can take the most weight is the winner!!
Engineering project: Design Research Construct Test Criticise and Improve!
Research When starting our engineering project, we need to consider three important things.... Economics
Economics • Take less time • Have less staff • Use less materials Money it will cost to build Vs Money it will generate when built How can we keep costs low? Golden gate bridge The project cost more than $35 million to build and took over four years. Provided essential route to mainland San Francisco
Safety How safe is it for the public to use? How safe is it to build for workers? Ethics Where is it being built? Will people lose out if a new bridge is made?
Science - Forces and Physics!! Simple beam bridge - rigid horizontal structure that is resting on two piers The weight is acting directly downward, through the centre of mass
Science – Forces and Physics!! Compression is a force that acts to compress or shorten an object. Tension is a force that acts to expand or lengthen an object. If the compression is too large we get buckling. If the tension is too large we get snapping.
Truss - Creates both a very rigid structure It transfers the load from a single point to a considerably wider area
Arch bridges Always under compression. The force of compression is pushed outward along the curve of the arch to the piers. This greatly reduces the effects of tension on the underside of the arch. The smaller the semicircle of the arch, the greater the tension relief effect.
Sydney Harbour Bridge Australia Kintai Bridge Iwakuni, Japan
Design Research Construct Test Criticise and Improve!
Rules Design and make a bridge to cross a 30cm gap. Use as much of the materials provided as you like. Test the maximum mass the bridge can take. Divide this by the weight of the bridge to get the score for the bridge Max. Mass Bridge score = Bridge Mass