1. Type of stucture
1.1. Shell Structure
1.1.1. Shell Structure is a type of structure that is hollow and strong,but very light.
1.2. Solid Structure
1.2.1. Solid structure is a type of structure that has a very large mass. Solid structures can hold heavy loads.
1.3. Frame Structure
1.3.1. Frame structure is a type of structure that can be very strong and lighter than solid structure. Frame Structure looks like a skeleton for building.
2. Internal Force
2.1. internal forces is a force from the inside of a structure. there is four type of internal force: tension ,compression, torsion, and shear.
2.1.1. compression: pressing or squishing in the opposite dircection object is compression
2.1.2. -tension: stretching or pulling an object in the opposite direction is tension.
2.1.3. torsion: twisting an object in different directions
2.1.4. shear: breaking something in half by ripping the object in different directions.
3. External force
3.1. External forces is something that impacts a object or a structure on the outside. for an example a push or pull
3.1.1. for an example this man is pushing the lawn mower to cut the grass
3.1.2. Another example is this man is pulling on this rope to gain something he wants/needs.
4. Loads
4.1. loads can be two things. a static load and a dynamic load.
4.1.1. Static loads are caused by gravity. like for an example the gravity is pushing against the rocks.
4.1.1.1. there are also dead loads. Dead loads ais gravity acting on the structure. For an example, gravity is pushing down the house.
4.1.1.2. live loads is the weight the structure /object holds. for an example this person is a live load
4.1.2. Dynamic load
4.1.2.1. Dynamic load can be caused by the wind, tornado, earthquake etc.
5. purpose, form, and function
5.1. Purpose: For example, a dam's purpose is to water supply, flood control, hydropower etc. another example is a school, it's purpose is to let us use the classrooms to learn, and let the teacher to teach us things.
5.2. form: the form of a structure dependence on object's function, for example a pencil sharpener have a sharp blade because it uses the blade to cut the wood of the pencil.
5.3. function: the function of a pencil sharpener is it sharpen pencils, and a eraser's function is to erase pencil marks.
6. Center of gravity
6.1. center of gravity is the point of an object that gravity pushes down on. on the center of gravity you are able to spin the object around and it will stay still.
6.1.1. like for an example when you balance the ruler on your finger the center of gravity is in the middle. this is because most amount of gravity is pushing in the middle than the two ends.
6.1.2. another example is when you balance a broom stick the most amount of gravity is near the broom part of your stick. since the two ends of the stick is heavier than the other side, the center of gravity has changed on to one side.