A cantilever truss works by extending outwards from a single support, carrying its load through specific force distributions within its structure.
Understanding Cantilever Trusses
Unlike a typical truss supported at both ends, a cantilever truss projects horizontally into space, supported only at one end or point along its length. This unique structural form is designed to handle the bending forces created by the overhanging portion.
Force Distribution within the Truss
According to the provided information, cantilever trusses manage their loads through distinct internal forces:
- Upper Chords: The upper chords of a cantilever truss are under tension. This means they are being pulled or stretched as they support the weight hanging from the cantilever.
- Lower Chords: Conversely, the lower chords are under compression. This means they are being pushed or squeezed together.
This distribution of forces is critical for maintaining the truss's stability and capacity to carry loads over a distance without support from below.
Support Mechanism
The reference explains how the support structure interacts with the cantilever truss:
- Each cantilever truss is often supported by a tower.
- The tower's interior structure is responsible for carrying the compression forces from the cantilever truss downwards to the foundation.
- The tower's exterior structure is designed to handle the tension forces, carrying them outwards to the foundations located further away, typically supporting an adjacent span.
Here's a simplified look at the force distribution:
| Truss Member | Primary Force | Description |
|---|---|---|
| Upper Chord | Tension | Pulled/Stretched |
| Lower Chord | Compression | Pushed/Squeezed |
| Tower Interior | Compression | Carries downward to foundation |
| Tower Exterior | Tension | Carries outwards to foundations |
Practical Applications
Cantilever trusses are frequently used in structures where intermediate supports are impractical or impossible. Common examples include:
- Bridges: Forming spans over waterways or valleys, often meeting in the middle or supporting a suspended span.
- Balconies and Overhangs: Creating projecting structures on buildings.
- Cranes and Industrial Structures: Providing reach and lifting capacity.
By strategically distributing tension and compression forces, cantilever trusses effectively counteract gravity and bending moments to create stable, projecting structures.
