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4. What is a Truss?

# What is a Truss?

## Truss Definition: What is a Truss?

A Truss is an important structure type in structural engineering. So what are trusses? A Truss is a triangulated system of members that are structured and connected in a way such that they only incur axial force. These members are considered two-force members as the forces are only applied at either end of the member, resulting in either a compression or tension force. They are commonly used as bridge designs, given their ability to efficiently span long distances. A typical truss might look something like this:

Source: Truss Rafter Calculator

The joints are typically pinned connections, such that no shear or moment forces are transferred from member to member. This is a major, yet commonly misunderstood, difference between truss and frame structures. A frame member will typically take a combination of shear, axial, and bending forces; whereas a truss member will only take axial force.

## Benefits of a Truss

When designed correctly, trusses are an efficient way to span long distances whilst minimizing the amount of material used. This is because the internal loads of the members are induced axially (in the direction of the member) in the form of compression or tension. This means less material can be used, and the system as a whole is more efficient, as the force is distributed among a number of members.

Source: Roof Truss Calculator

## Types of Trusses

What are the types of trusses? There are a number of different trusses based on their shapes and layout. Here’s a list of the different types of trusses (click a truss type to learn more about that design):

We hope you have found this definition of a truss useful. Visit our Truss Calculator to use for yourself, and experiment on how trusses work.