Structural and Pneumatic Systems
How structures carry loads through parts in tension and compression, and how pneumatic systems use compressed air, moving through a compressor, reservoir, valve and cylinder, to create controlled movement.
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Structures and air power
Engineers design systems that carry loads and create movement. A structural system holds a load without falling down, using parts that are pushed or pulled. A pneumatic system uses compressed air to make things move. This module looks at how structural and pneumatic systems work.
Structural and pneumatic terms
Learn these four terms before you study the two systems.
Tension or compression?
Every part of a structure is either being pushed or pulled by the load.
Struts push, ties pull
A quick way to remember: a strut is squashed, and both words start with s, so it is in compression. A tie is pulled tight, so it is in tension. When you look at a structure, work out whether each part is being pushed or pulled, then name it a strut or a tie.
Match the structural part
- strut
- tie
- beam
- triangle
- a tent pole holding a tent up
- a crane cable lifting an engine
- a shelf that spans a gap and bends
- the shape that makes a frame rigid
Match the pneumatic part
- compressor
- reservoir
- valve
- piston
- squeezes air into a smaller space
- stores the air ready for use
- controls the direction the air flows
- slides inside the cylinder to push the load
Push or pull?
A steel cable holds up a heavy sign and is being pulled tight by the weight. How is the cable acting?
- As a tie, because it is in tension.
- As a strut, because it is in compression.
- As a beam, because it bends in the middle.
- As a piston, because it slides.
Facts about pneumatics
Select the TWO statements that are true about pneumatic systems.
- They use squeezed air to create movement.
- A compressor raises the pressure of the air.
- They run on electricity flowing through wires.
- They change speed using a gear train.
The path of the air
Put the flow of air through a pneumatic system in order, earliest first.
- Air is drawn into the compressor
- The compressor squeezes the air
- The air is stored in the reservoir
- A valve sends air to the cylinder to move the piston
Complete the systems facts
A tent pole holding a tent up is acting as a _____. A cable lifting a heavy load is acting as a _____. A pneumatic system is powered by squeezed _____. The part that squeezes the air is the _____. The squeezed air is then stored in the _____.
Work out the pressure
A force of 200 newtons acts on a piston with an area of 4 square centimetres. Pressure = force divided by area. What is the pressure in newtons per square centimetre?
Find the parts in tension
Tap the TWO parts that are in tension, meaning they are being pulled.
- a crane cable lifting a load
- a table leg under a heavy top
- a rope holding up a swing
- a pillar holding up a roof
Strut, tie or neither?
Decide whether each part is a strut, a tie, or neither.
- A vertical pillar holding up the weight of a roof
- A cable stopping a tall mast from falling by pulling it tight
- The squeezed air inside a pneumatic reservoir
Explain a pneumatic system
Explain how a pneumatic system uses compressed air to create movement, and describe what the main parts do.
- Name the main parts of a pneumatic system
- Explain what the compressor and reservoir do
- Explain how the cylinder and piston create movement