1. Structures

2. Classification of structures
Natural structures and manufactured structures
Natural structures
Structures that already exist in nature. For example. A tree
Manufactured
Structures that is manufactured by people, e.g. Window frame

3. 3 Types of structures Frame structure Shell structure
Mass-or solid structure

4. Frame structure
This structure exist of rods and bars that are connected together in a certain pattern, eg. Window frame, Eifel tower, etc…
Triangulation
Frame structures are most of the time connected in triangles, because it is very strong.We call it TRIANGULATION

5. Properties of Frame structures
It is not the strongest structure.
Support loads, span areas, or both.
Is connected in triangles.

6. Shell structure
It is a structure that protects or enclose something, eg. Hat, Shoe box, Coffin, Car, etc…
Properties of shell structure
Lighter than frame structure but can support the same load.
Bigger weight-to force ratio than frame structures
Is hollow.

7. Mass- or solid structure
This structure is solid and consist of the same type of material stacked on each other, eg. Pillar, Brick, concrete slab, candle, iron block, etc…

8. Properties of structures
The reason why a lot of buildings or frameworks break or fail, is because of choosing the wrong material.
Therefore we need to keep the properties of a material in mind when we build something.

9. 8 Properties Elasticity Plasticity Ductility Malleability Hardness
Stiffness
Flexibility
Toughness

10. Elasticity
The ability of a material to regain its original position after being deformed, e.g.
If you kick a soccer ball it will deform, but it will regain its original shape again.

11. Plasticity
The ability of a material to change its shape permanently, e.g.
Clay or cool drink cans can be melt or reshaped into new forms.

12. Ductility
The ability of a material to stretch without breaking and regain its original shape, e.g.
A rubber can be stretched when you pull on both sides.

13. Malleability
The ability of a material to be deformed in all directions without cracking, e.g.
If you press clay in all directions
In the old days they heated steel rods and hit it with a hammer in all directions to get a sword.

14. Hardness
The ability of a material to withstand scratching, deforming and wear and tear.
A hard material will scratch a softer material, e.g.
Diamantes is the hardest material that exists, and it will scratch other material.

15. Stiffness
This is the ability of a material to not bend when a external force is applied, e.g.
Window frame bars wont bend, because of its stiffness.
A Straw we use to drink cool drink don’t have a lot of stiffness and it will bent easily.

16. Flexibility The ability of a material to bend without breaking, e.g.
Soft plastic ruler can bend a lot.
A golf club and fishing rod also has a good flexibility.

17. Toughness The ability of a material to resist breaking, e.g.
A plate that falls on the ground will break because of a weak toughness.
Tennis ball will hop on the floor, because of a good toughness

18. Test What is the two classifications of structures?
What is the definition of a frame structure?
Give the 8 properties that can work in on materials.