Definitions
A supporting framework with a specific size, shape, and purpose, that holds a load.
Is a birds nest a man-made structure or a natural structure?
Natural Structure
Is a desk stable or unstable?
Stable
If you had to build a long bridge across a river, what material would you choose?
Steel - it is strong and durable
What is a load?
A weight that a structures must support.
Man-made!
Is a hammock stable or unstable?
What is a strong shape to build with?
Triangles
What does stability mean?
What are man-made structures?
Man-made structures are human built structures.
Is a motorcycle a stable or unstable structure?
Unstable
How can you alter or change a material to make it stronger?
1. Fold
2. Twist or braid
3. Add layers
What is compression.
Compression is a force that pushes down on a structure (tension is a pulling force).
Give an example of a man-made structure?
(desk, chair, buildings, cars, pencils)
How can you increase the stability of a structure?
(Make a wider base, build a deep foundation, lower the center of gravity)
What can you add to a structure to work against compression and tension?
Struts and ties
What is the center of gravity?
The point on a structure where there is equal weight above and below.
Give an example of a natural structure.
(tree, birds nest, cave, egg, bee hive, iceburg)
Are structures with a higher center of gravity or a lower center of gravity more stable?
Lower center of gravity - adding mass or width to the base lowers the center of gravity.
A truss