Shear lag theory

Question 1

How does the interfacial shear stress between fibre and matrix relate to the fibre stress in short fibre composites?

Answer 1

Interfacial shear stress is related to the change in the fibre stress.

Question 2

Why does the fibre stress reach a maximum plateau quicker in short SiC fibres in glass than short C fibres in epoxy?

Answer 2

There is less of a mismatch between the fibre and matrix stiffnesses in the SiC in glass.

Question 3

What is the key difference between shear lag theory and modified shear lag theory for short fibre composites?

Answer 3

Shear lag theory assumes zero stress at the fibre ends, whereas modified shear lag theory does not.

Question 4

The equation for the aspect ratio required for long fibre behaviour to be seen in short fibre composites is what number divided by n?

Answer 4

10

Question 5

What is the correct order of fibre orientations for stiffness (lowest to highest) in short fibre composites?

Answer 5

3D < 2D < 1D

Question 6

Roughly, what aspect ratio is required for short fibres to stop fracturing into smaller lengths under load in polymer matrix composites?

Answer 6

100