Question

A torsion experiment is performed on rods made from glass, a ductile metal and wood. What failure criteria would you use, what do you expect the failure surfaces to look like (including orientation) and why?

Answer 1

Answer:

• when the fracture parts when put together look intergranual ( glass fractures intergranually )

The Failure surface looks flat ( very ) and bright

•   when the fracture is a cup and cone fracture ( Ductile metal )

The failure surface looks dull and also absorbs light

• wood fracture

The failure surface looks like both some fraction brittle and some fraction ductile.

Explanation:

• when the fracture parts when put together look intergranual ( glass fractures intergranually )

The Failure surface looks flat ( very ) and bright

•   when the fracture is a cup and cone fracture ( Ductile metal )

The failure surface looks dull and also absorbs light

• wood fracture

The failure surface looks like both some fraction brittle and some fraction ductile.