# Structures and Forces Max Tan
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o registrati con il tuo indirizzo email Structures and Forces da ## 1. Types of structures

### 1.1. Shell Structures

1.1.1. Shell structures are hollow, light and strong structures.

1.1.1.1. An example of a shell structure can be an igloo.

1.1.1.1.1. Igloo

1.1.1.2. Another example could be an egg.

1.1.1.2.1. Egg

1.1.1.3. Another example could be a balloon.

1.1.1.3.1. Balloon

### 1.2. Solid Structures

1.2.1. Solid Structures are structures that are solid all the way through. Solid structures are heavier and use up more materials to make.

1.2.1.1. An example of a solid structure can be a sandcastle.

1.2.1.1.1. Sandcastle

1.2.1.2. Another example could be a banana.

1.2.1.2.1. Banana

1.2.1.3. Another example could be a mountain.

1.2.1.3.1. Mountain

### 1.3. Frame Structures

1.3.1. Frame Structures are parts put together. A frame structure connects itself to different parts of the structure.

1.3.1.1. An example of frame structures can be a skeleton.

1.3.1.1.1. Skeleton

1.3.1.2. Another example could be a car.

1.3.1.2.1. Car

1.3.1.3. Another example could be a spider web.

1.3.1.3.1. Spider Web

### 1.4. Combination structures

1.4.1. Combinations structures are made up of combinations of the different types of structures(shell, frame and solid structures).

1.4.1.1. An example of combination structures can be a house.

1.4.1.1.1. House

1.4.1.2. Another example could be a person.

1.4.1.2.1. Person

1.4.1.3. Another example could be the One World Trade Center.

### 1.5. Strength

1.5.1. The strength of a structure is the structure's capability to hold off forces.

1.5.1.1. An example of a structure's strength can be a house not getting knocked down by the wind.

1.5.1.1.1. House pushing against wind

1.5.1.2. Another example of a structure's strength could be a bridge not collapsing under a truck's weight.

1.5.1.2.1. Bridge with truck

1.5.1.3. Another example could be a building being able to withstand the force of snow hitting it..

1.5.1.3.1. Snow hitting building

## 2. Types of Forces

### 2.1. Internal Forces

2.1.1. An internal force occurs when one part of a structure puts force on other parts of the structure.

2.1.1.1. Compression

2.1.1.1.1. The force of a structure being pressed together.

2.1.1.2. Tension

2.1.1.2.1. The force of a structure being pulled apart.

2.1.1.3. Torsion

2.1.1.3.1. The force of a structure being twisted.

2.1.1.4. Shear

2.1.1.4.1. The force of a structure being bended or moved in opposite directions.

### 2.2. External Forces

2.2.1. An external force occurs when any force is acted upon on the outside of the structure.

2.2.1.1. Friction

2.2.1.1.1. When a structure is resisting being slid on another object, usually the ground.

2.2.1.2. Gravity

2.2.1.2.1. The force that brings structures down on earth or any other mass. The bigger the mass, the more gravity it has.

## 3. Design of structures

### 3.1. Center of gravity

3.1.1. The center of gravity is where the center of all the weight is. The structure's weight is balanced the same on all sides from the center of gravity.

3.1.1.1. An example of center of gravity can be the wings of a plane.

3.1.1.1.1. Plane

3.1.1.2. Another example could be the midsection of a giraffe.

3.1.1.2.1. Giraffe

### 3.2. Stability

3.2.1. Stability is the structure's capability to keep it's posture when a external force has been put on it.

3.2.1.1. An example of stability can be a bridge.

3.2.1.1.1. Bridge

3.2.1.2. Another example could be a building/tower.

3.2.1.2.1. Building

### 3.3. Structural Stress

3.3.1. When internal and external forces overloads a structure over some time to cause it to be temporary impaired and may be reversible.

3.3.1.1. An example of structural stress can be a broken bone.

3.3.1.1.1. Broken Bone

3.3.1.2. Another example could be the spine of a book that has been bended too much.

3.3.1.2.1. Spine of Book

3.3.1.3. Another example could be a bookshelf with too many books so it bends.

3.3.1.3.1. Bookshelf bending

### 3.4. Structural Fatigue

3.4.1. When a structure is overloaded with internal and external forces for too long, and the structure cannot return to it's original shape.

3.4.1.1. An example of structural fatigue can be a smashed aluminum can.

3.4.1.1.1. Aluminum Can

3.4.1.2. Another example can be a crumpled piece of paper.

3.4.1.2.1. Paper

### 3.5. Structural Failure

3.5.1. When a structure has experienced such a large amount of structural stress and structural fatigue that it is no longer able to function properly.

3.5.1.1. An example of structural failure can be a collapsed bridge.

3.5.1.1.1. Collapsed Bridge

3.5.1.2. Another example can be a broken car.

3.5.1.2.1. Broken Car

3.5.1.3. Another example could a fallen house

3.5.1.3.1. Fallen house

### 3.6. Structural components

3.6.1. Materials that can help the structure be stabler and have more strength.

3.6.1.1. An example of a structural component can be I beam.

3.6.1.1.1. Beam

3.6.1.2. Another example could be a column.

3.6.1.2.1. Column

3.6.1.3. Another example could be an arch.

3.6.1.3.1. Arch

4.1.1.1.1. Chair

4.1.1.2. Another example could be a pencil case.

4.1.1.2.1. Pencil Case

4.1.1.3. Another example could be a bridge.

4.1.1.3.1. Bridge

4.2.1.1. An example of a live load can be a person sitting on a chair(live load is the person)

4.2.1.1.1. A Person Sitting

4.2.1.2. Another example could be bacon on a pan(live load is the bacon).

4.2.1.2.1. Bacon

4.2.1.3. Another example could be a book sitting on a desk(live load is the book).

4.2.1.3.1. Book on a desk

4.3.1. A dynamic load is a force that is acting upon a structure that can change the shape or directions of the object.

4.3.1.1. An example of a dynamic load can be wind pushing against a building(the dynamic load is the wind).

4.3.1.1.1. Wind

4.3.1.2. Another example could be rain.

4.3.1.3. Another example could be snow.

4.3.1.3.1. Snow

### 4.4. Rain

4.5.1. A static load is a force that is constantly being applied to an object; like weight.

4.5.1.1. An example of a static load is the weight of the tree on the tree.

4.5.1.1.1. Tree

4.5.1.2. Another example could be the weight of the soil on the earth.

4.5.1.2.1. Soil

4.5.1.3. Another example could be the gravity that pulls down on a chair.

4.5.1.3.1. Chair

## 5. Describing Forces

### 5.1. Magnitude

5.1.1. Magnitude is the amount of force being applied to a certain point of a structure.

5.1.1.1. An example of magnitude can be a scale 5 tornado.

5.1.1.2. Another example could be a car traveling at 100 kilometers an hour.

5.1.1.2.1. Car

### 5.2. Direction

5.2.1. Direction is where the force is coming from.

5.2.1.1. An example of direction can be where a foot hits a ball (left, right middle).

5.2.1.1.1. Ball

5.2.1.2. Another example could be where a golf club hits a golf ball (left, right, middle).

5.2.1.2.1. Golfing

### 5.3. Point of application

5.3.1. The point of application is the exact place where the force is hitting the structure.

5.3.1.1. An example of point of application can be the exact point where a wrecking ball hits.

5.3.1.1.1. Wrecking Ball

5.3.1.2. Another example could be the building window being smashed.

5.3.1.2.1. Smashed Window

### 5.4. Plane of application

5.4.1. The plane of application is the invisible line the force is hitting the structure.

5.4.1.1. An example of plane of application can be the front of a building. (The plane of application is the front).

5.4.1.1.1. Building

5.4.1.2. Another example could be a person standing on a building. (The plane of application is going down).

5.4.1.2.1. Standing