Forces and Structures: Exploring the World of Engineering

• Science
• Secondary Education
• Age 13

Forces and Structures: Exploring the World of Engineering

Learning Objective

At the end of the lesson, you will be able to identify and explain the 5 different kinds of forces and understand the basics of various structural designs.

What do you already know about forces and structures?

5 Different Kinds of Forces

Introduction to the 5 different kinds of forces, 

- Compression

- Tension

- Shear

- Torsion

- Bending

Compression

Definition: A force that squeezes or pushes materials together.

Example: The force exerted on columns or beams in a building.

Tension

Definition: A force that pulls or stretches materials apart.

Example: The force experienced by cables in a suspension bridge.

Shear

Definition: A force that causes parts of a material to slide past each other in opposite directions.

Example: The force acting on a beam when a load is applied off-center.

Torsion

Definition: A twisting force that causes a material to rotate.

Example: The force applied to a drive shaft in a vehicle.

Bending

Definition: A force that causes a material to curve or bend.

Example: The force acting on a horizontal beam when a weight is placed in the middle.

3 Types of Structures

Solid Structures:

Definition: Solid structures, also known as mass structures, are made from a solid piece or multiple solid pieces of material. These structures rely on their mass for support and stability.

Examples: Dams, walls, and bricks.

Characteristics: They are generally strong, heavy, and can withstand large forces. They don't have any hollow spaces within them and are often used to support heavy loads.

Frame Structures

Definition: Frame structures are made from a network or skeleton of strong materials arranged to support loads. These structures are often constructed from interconnected parts, creating a framework that can bear weight.

Examples: Bridges, towers, and skeletons of buildings.

Characteristics: They are usually lighter than solid structures and can be more flexible. They can span large distances and are often used in buildings and other constructions where support over a large area is required.

Shell Structures

Definition: Shell structures are thin, curved, and hollow. They are designed to distribute applied forces across their surface.

Examples: Domes, car bodies, and eggshells.

Characteristics: They are lightweight but can be very strong due to their shape. They are efficient in terms of material usage and are often used in architecture and manufacturing for aesthetic and functional purposes.

Bridges

Bridges

Beam Bridges

Overview of beam bridges, including their structural components and how they support weight.

Truss Bridges

Explanation of truss bridges and how their design provides strength and stability.

Arch Bridges

Arch bridges have a unique structural design that distributes weight evenly.

Suspension Bridges

Explanation of suspension bridges, their characteristic features, and the forces at play in their design.

Structural Failures and Famous Examples

Discussion of structural failures, their causes, and notable examples in engineering history.

Write down 3 things you learned in this lesson.

Have students enter three things they learned in this lesson. With this they can indicate their own learning efficiency of this lesson.

Write down 2 things you want to know more about.

Here, students enter two things they would like to know more about. This not only increases involvement, but also gives them more ownership.

Ask 1 question about something you haven't quite understood yet.

The students indicate here (in question form) with which part of the material they still have difficulty. For the teacher, this not only provides insight into the extent to which the students understand/master the material, but also a good starting point for the next lesson.