Specific stiffness - Specific strength
Metals and alloys
Wood and wood products
- Specific properties are properties that have been divided by the material density.
- This chart is useful for identifying materials for components which require high stiffness and/or strength combined with low weight
- Composites provide a means of achieving good specific properties.
- The bubbles are elongated along the specific strength axis, but not specific stiffness. This is because alloying and heat treatments have a strong effect on strength but little on stiffness and density
- Note that high strength and high stiffness often go together - this is because they are both largely controlled by the atomic bonding
- Bicycle frames require high specific stiffness to prevent bending and high specific strength to prevent failure, at low weight
- Aircraft have many aluminium structures because they offer low weight at sufficient strength and stiffness
- Explain why bike frames are made from steel, aluminium alloy or carbon-fibre reinforced plastic?
- Select materials for a tennis racquet.
- Select materials for a canoe.
- Select materials for a cast for a police truncheon.
- Why are cast-iron cooking pans among the best when they are the heaviest?
- Why are composites used more widely for sports goods than elsewhere?